The present invention relates to a permanent magnet type AC synchronous
motor including a linear and a rotary motor, wherein initial magnetic poles of
the AC synchronous motor are estimated without using a magnetic pole sensor (pole
sensor).

Background Art

Information on an initial magnetic pole position detected from a
magnetic pole sensor is required when an AC synchronous motor is started, such
that the AC synchronous motor operates in accordance with commands based on correct
information on a detected initial magnetic pole position. There may arise such
problems as when the information on the detected initial magnetic pole position
shifts from the magnetic pole position of the AC synchronous motor by ±90 degrees,
no torque is generated so that the AC synchronous motor does not operate, and when
the shift exceeds ±90 degrees, the AC synchronous motor reversely rotates as opposed
to a command. From such reasons, the correct information on a detected initial
magnetic pole position is critical in the AC synchronous motor, so that a variety
of initial magnetic pole estimating methods have been devised for AC synchronous
motor in order to acquire correct information on a detected initial magnetic pole
position. A relationship between an offset angle of an initial magnetic pole position
and a generated torque (hereinafter, a thrust force of a linear motor is also
shown as a torque) is represented by Equation (1) and shown in Fig. 16.
T = Tm x cos(&thetas;error)
where T is a generated torque, Tm is a maximum value of the torque, and &thetas;error
is an offset angle of the initial magnetic pole position.

A prior art technique described in Japanese Patent Laid-Open No.
153576/1994 applies a voltage corresponding to an arbitrary initial magnetic pole
position angle to estimate the initial magnetic pole position from information
on a rotating direction and a rotational speed of a motor at that time. This initial
magnetic pole estimating method repeats the estimation to find a correct initial
magnetic pole position.

However, the prior art technique involves a repetition-based trial
and error method which approaches from a wide estimation error range to a narrower
estimation error range of the initial magnetic pole position to estimate a true
value for the initial magnetic pole position of an AC synchronous motor, and experiences
the following problems:

(1) a correct initial magnetic pole position cannot be estimated (a magnetic
pole position estimation accuracy range is within ±30°);

(2) a motor operation range can become wider during an estimation of an initial
magnetic pole position;

(3) an estimation time can be long; and

(4) an application to a load is difficult if disturbance such as a large static
friction, cogging and the like exists in the load.

To solve the foregoing problems, it is an object of the present invention
to make full use of the performance and characteristics of an AC synchronous motor
by:

(1) the ability to estimate a magnetic pole position in a short time;

(2) the ability to freely set a range in which the motor can operate;

(3) the ability to minimize a range in which the motor can operate;

(4) the applicability to a load even if disturbance or large cogging torque
exists in the load; and

(5) the ability to correctly estimate a true value for an initial magnetic
pole position.

Disclosure of the Invention

The gist of an initial magnetic pole estimating apparatus for an
AC synchronous motor according to the present invention lies in the following (1)
- (32).

(1) An initial magnetic pole estimating apparatus for an AC synchronous motor,
equipped in an AC synchronous motor controller comprising speed control means for
calculating a command torque (command current) from a command speed, current control
means for driving the AC synchronous motor in accordance with the command torque
(command current), and a PWM power converter, wherein the initial magnetic pole
estimating apparatus is characterized by having speed deviation calculating means
for subtracting the detected speed from the command speed generated by command
speed pattern generating means to calculate a speed deviation, a speed gain control
unit for multiplying the speed deviation by a speed gain to calculate a command
torque (command current), mode section determining means for determining a mode
section (a first cyclic section and a second cyclic section) from the command
speed, a mode switch for switching a mode section to any of the first cyclic section
and the second cyclic section in accordance with a result in the mode section
determining means, data acquisition speed section determining means for determining
whether the command speed is in a data acquisition speed section when the first
cyclic section is selected, a first command torque calculating means (first command
current calculating means) for calculating first command torque data (first command
current data) from the command torque (the command current) in the determined data
acquisition speed section, data acquisition speed section determining means for
determining whether the command speed is in the data acquisition speed section
when the second cyclic section is selected, second command torque calculating means
(second command current calculating means) for calculating second command torque
data (second command current data) from the command torque (the command current)
in the determined data acquisition speed section, and estimated initial magnetic
pole calculating means for calculating an estimated initial magnetic pole position
using information on the first command torque data (the first command current
data) and the second command torque data (the second command current data).

(2) An initial magnetic pole estimating apparatus for an AC synchronous motor
equipped in an AC synchronous motor controller comprising PWM power converting
means for converting a direct current voltage to an arbitrary alternate current
voltage to drive the AC synchronous motor, three-phase current detecting means
for detecting a three-phase current of the AC synchronous motor, an electric angle
detecting means for detecting a relative electric angle of the AC synchronous motor,
three-phase/two-phase coordinate conversion calculating means for performing a
three-phase/two-phase coordinate conversion from a detected three-phase current
to a detected two-phase current using the detected electric angle, detected speed
calculating means for calculating a detected speed from the detected electric angle,
two-phase current error calculating means for subtracting the detected two-phase
current from a two-phase command current comprised of a q-axis command current
and a d-axis command current to calculate a current error, a two-phase current
proportion integration control unit for multiplying the current error by a two-phase
current proportion integration gain to calculate a two-phase command voltage,
two-phase/three-phase coordinate conversion calculating means for performing a
two-phase/three-phase coordinate conversion from the two-phase command voltage
to a three-phase command voltage using the detected electric angle, and PWM gate
pulse calculating means for comparing the three-phase command voltage with a carrier
waver to calculate a PWM gate pulse and outputting the PWM gate pulse to the PWM
power converting means, wherein the initial magnetic pole estimating apparatus
for an AC synchronous motor is characterized by having default initial magnetic
pole setting means for setting a default initial magnetic pole position to zero,
command speed pattern generating means for generating a command speed as a two-cycle
waveform, speed deviation calculating means for subtracting the detected speed
from the command speed to calculate a speed deviation, a speed gain control unit
for multiplying the speed deviation by a speed gain to calculate a command torque
(command current), mode section determining means for determining a mode section
(a first cyclic section and a second cyclic section) from the command speed, a
mode switch for switching a mode section to any of the first cyclic section and
the second cyclic section in accordance with a result in the mode section determining
means, acceleration section determining means for inputting the command torque
(the command current) to the q-axis command current and inputting zero to the d-axis
command current, when the first cyclic section is selected, and determining whether
or not the command speed is in a positive acceleration section, first command torque
calculating means (first command current calculating means) for calculating first
maximum command torque data (first maximum command current data) from the command
torque which is the determined positive acceleration section, first memory storing
means for storing the first maximum command torque in a memory, acceleration section
determining means for inputting zero to the q-axis command current and inputting
the command torque (the command current) to the d-axis command current when the
second cyclic section is selected, and determining whether or not the command
speed is in a positive acceleration section, second command torque calculating
means (second command current calculating means) for calculating second maximum
command torque data (second maximum command current data) from the command torque
which is in the determined positive acceleration section, second memory storing
means for storing the second maximum command torque in a memory, estimated initial
magnetic pole calculating means for calling the maximum command torques (first
and second maximum command torques) from the memories after the command speed
has terminated a second cycle to calculate an estimated initial magnetic pole position
using the information, and compensated initial magnetic pole calculating means
for adding the estimated initial magnetic pole position to the default initial
magnetic pole position to calculate a compensated initial magnetic pole position.

(3) An initial magnetic pole estimating apparatus for an AC synchronous motor
equipped in an AC synchronous motor controller comprising PWM power converting
means for converting a direct current voltage to an arbitrary alternate current
voltage to drive the AC synchronous motor, three-phase current detecting means
for detecting a three-phase current of the AC synchronous motor, an electric angle
detecting means for detecting a relative electric angle of the AC synchronous motor,
detected speed calculating means for calculating a detected speed from the detected
electric angle, three-phase command current calculating means for calculating three-phase
command current comprised of a A-phase command current, a B-phase command current
and a C-phase command current from a command torque (command current) using the
detected electric angle, three-phase current error calculating means for subtracting
the detected three-phase current from a three-phase command current to calculate
a current error, a three-phase current proportion integration control unit for
multiplying the current error by a three-phase current proportion integration gain
to calculate a three-phase command voltage, and PWM gate pulse calculating means
for comparing the three-phase command voltage with a carrier waver to calculate
a PWM gate pulse and outputting the PWM gate pulse to the PWM power converting
means, wherein the initial magnetic pole estimating apparatus for an AC synchronous
motor is characterized by having default initial magnetic pole setting means for
setting a default initial magnetic pole position to zero, command speed pattern
generating means for generating a command speed as a two-cycle waveform, speed
deviation calculating means for subtracting the detected speed from the command
speed to calculate a speed deviation, a speed gain control unit for multiplying
the speed deviation by a speed gain to calculate a command torque (command current),
mode section determining means for determining a mode section (a first cyclic section
and a second cyclic section) from the command speed, a mode switch for switching
a mode section to any of the first cyclic section and the second cyclic section
in accordance with a result in the mode section determining means, three-phase
command current converting means operative when the first cyclic section is selected
for adding a shift angle equal to zero degrees to the detected electric angle
(without phase change), and calculating the three-phase command current from the
command torque (the command current), acceleration section determining means for
determining whether or not the command current is in a positive acceleration section,
first command torque calculating means (first command current calculating means)
for calculating a value of a first maximum command torque (first maximum command
current) from the command torque which is in the determined positive acceleration
section, first memory storing means for storing the first maximum command torque
in a memory, the three-phase command current converting means operative when the
second cyclic section is selected for adding a shift angle equal to 90 degrees
to the detected electric angle (a phase change by 90 degrees), and thereafter calculating
the three-phase command current from the command torque (the command current),
acceleration section determining means for determining whether or not the command
speed is in a positive acceleration section, second command torque calculating
means (second command current calculating means) for calculating a value of a second
maximum command torque (second maximum command current) from the command torque
which is in the determined positive acceleration section, second memory storing
means for storing the second maximum command torque in a memory, estimated initial
magnetic pole calculating means for calling the maximum command torques (first
and second maximum command torques) from the memories after the command speed has
terminated a second cycle to calculate an estimated initial magnetic pole position
using the information, and compensated initial magnetic pole calculating means
for adding the estimated initial magnetic pole position to the default initial
magnetic pole position to calculate a compensated initial magnetic pole position.

(4) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (3), characterized in that the command
speed pattern generating means is capable of arbitrarily setting an acceleration/deceleration
section time and a constant speed section time, arbitrarily setting a speed waveform
in the acceleration/deceleration section, and arbitrarily setting an amplitude
value for a command speed to generate the command speed as a trapezoidal wave,
a triangular waver, a rectangular wave, a zero-speed wave, a sinusoidal wave,
and the like as a two-cycle waveform.

(5) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (4), characterized in that the speed
gain control unit functions as a speed proportion control unit, a speed proportion
integration control unit or a speed integration control unit in a combination of
a speed proportion control unit and a speed integration control unit.

(6) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (5), characterized in that the current
control means is a dq current control means (vector current control means), or
three-phase current control means.

(7) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (6), characterized in that in the dq
current control means used as the current control means, the command current is
inputted to the q-axis command current, and a constant value is inputted to the
d-axis command current in the first cyclic section, and the command current is
inputted to the d-axis command current, and a constant value is inputted to the
q-axis command current in the second cyclic section.

(8) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (7), characterized in that the constant
value is an arbitrary number.

(9) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (8), characterized in that in the
three-phase current control means used as the current control means, in the first
cyclic section, after a shift angle equal to zero degrees is added to the detected
electric angle (without phase change), the command torque (the command current)
is converted to a three-phase command current as shown in the following equations,
and in the second cyclic section, after a shift angle equal to 90 degrees is added
to the detected electric angle (phase change by 90 degrees) , the command torque
(the command current) is converted to a three-phase command current as shown in
the following equations.
Ia* = I* x cos(&thetas;fb - &thetas;shift) Ib* = I* x cos(&thetas;fb - &thetas;shift - 120 degrees) Ic* = I* x cos(&thetas;fb - &thetas;shift - 240 degrees)
where I* is a command torque (command current);

&thetas;fb is a detected electric angle (relative position);

&thetas;shift is a shift angle (zero degrees in the first cyclic
section, and 90 degrees in the second cyclic section);

Ia* is an A-phase command current;

Ib* is a B-phase command current; and

Ic* is a C-phase command current.

(10) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (9), characterized in that in the current
control means, the command torque (the command current) is treated as the command
current in the first cyclic section after a shift angle equal to zero degrees is
added to the detected electric angle (without phase change), and the command torque
(the command current) is treated as the command current in the second cyclic section
after a shift angle equal to 90 degrees is added to the detected electric angle
(phase change by 90 degrees).

(11) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (10), characterized in that the data
acquisition speed section is comprised of a combination of a positive acceleration
section, a negative acceleration section, a positive deceleration section, a negative
deceleration section, a positive constant speed section, and a negative constant
speed section.

(12) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (11), characterized in that the data
acquisition speed section determining means is acceleration section determining
means when the magnetic pole estimating data is acquired in an acceleration section;
constant speed section determining means when acquired in a constant speed section;
acceleration/constant speed section determining means when acquired in an acceleration
section and a constant speed section; deceleration/constant speed section determining
means when acquired in a deceleration section and a constant speed section; acceleration/deceleration
determining means when acquired in an acceleration section and a deceleration
section; and an acceleration/deceleration/constant speed section determining means
when acquired in an acceleration section, a deceleration section and a constant
speed section.

(13) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (12), characterized in that when the
data acquisition speed section determining means is the constant speed section
determining means, the magnetic pole estimating data is calculated after the arbitrary
time set due to the fact that it can be set from zero to an arbitrary time (however,
the arbitrary time is smaller than an end time of the constant speed section) until
the end time of the constant speed section.

(14) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (13), characterized by having first
memory storing means for storing the first command current data calculated in
the first cyclic section in a memory, and second memory storing means for storing
the second command current data calculated in the second cyclic section in a memory.

(15) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (14), characterized by calling the
command torque data (first and second command torque data) from the memory.

(16) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (15), characterized in that the estimated
initial magnetic pole position is calculated as expressed by tan^{- 1}
(the first command current data/the second command current data), or a combination
of cos^{- 1} and sin^{-}^{1}, or the estimated initial
magnetic pole position is calculated as expressed by Σ (tan^{- 1}
(the first instantaneous command current data/the second instantaneous command
current data))/k when the first and second command current data are instantaneous
command currents, or calculated from a relationship between the first command
current data and the second command current data.

(17) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (16), characterized in that the first
command current data and second command current data calculated by the first command
current calculating means and the second command current calculating means are
a maximum command current, an average command current and an instantaneous command
current, wherein the maximum command current is a maximum value calculated from
a command current which is in the data acquisition speed section, the average
command current is an average of the command current which is in the data acquisition
speed section, and the instantaneous command current is a command current which
is an instantaneously calculated command current which is in the data acquisition
speed section.

(18) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (17), characterized in that in the
command speed, a pause section in which the command speed has a zero command speed
is provided when switching between positive and negative, and a time for the pause
section can be arbitrarily set.

(19) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (18), characterized in that in the
command speed, a pause section in which the command speed is zero is provided
between a first cyclic section in a first cycle and a second cyclic section in
a second cycle, and a section is switched during the pause section.

(20) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (19), characterized in that the command
current, a pause section is provided when a forced phase change is performed,
and the phase change is performed in the pause section.

(21) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (20), characterized by having speed
integration gain processing means for performing speed integration gain processing
(clearing, holding and the like of an integration term) of the speed gain control
unit, when the first cyclic section is switched to the second cyclic section,
or when a forced phase change is performed, in the command current.

(22) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (21), characterized in that an axial
direction determining command speed provided for determining a direction (region)
of a torque axis or a magnetic flux axis of the AC synchronous motor uses a first
cyclic waveform of the command speed according to the foregoing (4).

(23) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (22), characterized in that a user
sets one or more of a speed deviation limit level, a torque limit level, a speed
limit level, and a data deviation limit level in a parameter setting memory within
the initial magnetic pole estimating apparatus for an AC synchronous motor.

(24) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (23), characterized in that excessive
speed deviation determining means compares a speed deviation calculated by subtracting
the detected speed from the axial direction determining command speed with the
speed deviation limit level to determine an excessive speed deviation of the motor.

(25) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (24), characterized in that excessive
torque determining means compares a command torque supplied from the speed control
unit with the torque limit level to determine an excessive command torque for the
motor.

(26) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (25), characterized in that excessive
speed determining means compares the detected speed with the speed limit level
to determine an excessive speed for the motor.

(27) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (26), characterized by dividing 360
degrees of electric angle by a certain positive integer n, assuming that
the torque axis exists in a certain direction within 360 degrees, controlling the
AC synchronous motor with an axial direction determining command speed, determining
an excessive speed deviation in the excessive speed deviation determining means,
and estimating a direction of the torque axis from the determination result.

(28) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (27), characterized by assuming that
the torque axis of the AC synchronous motor is in another direction in accordance
with the result of the excessive speed deviation determination, and estimating
the direction of the torque axis of the AC synchronous motor by repeating the
operation of controlling the AC synchronous motor with the axial direction determining
command speed, and determining the excessive speed deviation in the excessive
speed deviation determining means by a predefined subroutine.

(29) An initial magnetic pole estimating apparatus for an AC synchronous motor,
characterized by estimating the direction of the torque axis of the AC synchronous
motor in the axial direction determining means according to any one of the foregoing
(22) - (28), and thereafter estimating an initial magnetic pole position of the
AC synchronous motor in the calculation processing according to the foregoing
(1), (2) or (3).

(30) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (29), characterized in that excessive
data deviation determining means compares a difference between the first command
torque data and the second command torque data (data difference) with the data
deviation limit level to determine an excessive data deviation.

(31) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (30), characterized by determining
an excessive data deviation in the excessive data deviation determining means,
and estimating an initial magnetic pole position of the AC synchronous motor again
by the calculation processing according to the foregoing (1), (2) or (3) after
changing to a predefined phase, when the determination result shows "data deviation
≥ data deviation limit level."

(32) An initial magnetic pole estimating apparatus for an AC synchronous motor
according to any one of the foregoing (1) - (31), characterized in that the AC
synchronous motor is a rotary motor or a linear motor.

Brief Description of the Drawings

Fig. 1 is a general block diagram of a speed control including an initial magnetic
pole estimating apparatus directed by the present invention;

Fig. 2 is a block diagram of a speed control based on a dq current control
(vector control) including an initial magnetic pole estimation method for an AC
synchronous motor according to an embodiment of the present invention;

Fig. 3 is a detailed block diagram related to the initial magnetic pole estimating
method for an AC synchronous motor according to the embodiment of the present
invention;

Fig. 4 is a detailed block diagram related to the initial magnetic pole estimating
method for an AC synchronous motor according to the embodiment of the present
invention;

Fig. 5 is a diagram related to a command speed pattern (trapezoidal wave) having
a command speed over two cycles according to the embodiment of the present invention;

Fig. 6 is a diagram related to a command speed pattern (triangular wave) having
a command speed over two cycles according to the embodiment of the present invention;

Fig. 7 is a diagram related to a command speed pattern (rectangular wave) having
a command speed over two cycles according to the embodiment of the present invention;

Fig. 8 is a diagram related to a command speed pattern (zero-speed wave) having
a command speed over two cycles according to the embodiment of the present invention;

Fig. 9 is a diagram related to a dq mode switch in the detailed block diagram
of the initial magnetic pole estimating method illustrated in Fig. 3;

Fig. 10 is a flow chart related to the initial magnetic pole estimating method
for an AC synchronous motor according to the embodiment of the present invention;

Fig. 11 is a flow chart related to the initial magnetic pole estimating method
for an AC synchronous motor according to the embodiment of the present invention;

Fig. 12 is a flow chart for determining a region of a torque axis or a magnetic
flux axis according to the embodiment of the present invention;

Fig. 13 is a flow chart related to a "subroutine for determining the direction
of the torque axis" at S108 in the flow chart of Fig. 12;

Fig. 14 is a flow chart continued from a position (A) in the flow chart of
Fig. 13;

Fig. 15 is a diagram in which 360 degrees are divided into eight for representing
respective directions in accordance with the embodiment of the present invention;
and

Fig. 16 is a diagram showing a relationship between an offset angle of an initial
magnetic pole position and a generated torque.

In the drawings, * is a suffix indicative of a command; fb is a suffix
indicative of detection; d-q indicates a two-phase coordinate system; a-b-c indicates
a three-phase coordinate system; Vt indicates a carrier triangular wave voltage;
Vdc indicates a direct current voltage of a PWM invertor; Vq*, Vd* indicate command
voltages for a d-axis and a q-axis in the two-phase coordinates; Va*, Vb*, Vc*
indicate command voltages in an a-phase, a b-phase and a c-phase in the three-phase
coordinate system; Va, Vb, Vc indicate output voltages of an invertor in the a-phase,
b-phase and c-phase in the three-phase coordinates; T* indicates a command torque;
I* indicates a command current; Tm, T, Tloss indicates a maximum torque value,
a generated torque (thrust force) and a torque loss; Iq*, Id* indicate command
currents fr the q-axis and d-axis in the two-phase coordinates; Ia, Ib, Ic are
actual currents in the a-phase, b-phase, c-phase in the three-phase coordinates;
Iafb, Ibfb, Icfb are detected currents in the a-phase, b-phase, c-phase in the
three-phase coordinates; Δ Iq, Δ Id indicate current errors on the
q-axis and d-axis in the two-phase coordinates; I1data*, I2data* indicate first
command current data and second command current data; I1data*call, I2data*call
indicate call first command current data and call second command current data;
I1max*, I2max* indicate a first maximum command current and a second maximum command
current; I1ave*, I2ave* indicate a first average command current and a second
average command current; I1inst*[k], I2inst*[k] indicate a first instantaneous
command current at time k and a second instantaneous command current at
time k; &thetas; error indicates an offset angle of an initial magnetic
pole position; &thetas; 0 indicates a default initial magnetic pole position at
an initial setting; &thetas; est, &thetas; comp indicate an estimated initial magnetic
pole position and a compensated initial magnetic pole position; &thetas; estmax,
&thetas; estave, &thetas; estinst indicate an estimated initial magnetic pole
position calculated using a maximum command current, an estimated initial magnetic
pole position calculated using an average command current, and an estimated initial
magnetic pole position calculated using an instantaneous command current; ω*,ω
fb indicate a command speed and a detected speed; Δ ω indicates a speed
deviation; MAX indicates a maximum value calculating function; FNC is an arbitrary
function; ABS is an absolute value calculating function; Gau, Gbu, Gcu, Gad, Gbd,
Gcd indicate pulses of a gate 6 in a PWM invertor; sp_err indicates a speed deviation
determination flag; safe_area indicates an axial direction determination flag.

Reference numeral 1 designates an initial magnetic pole estimating
apparatus and method according to the present invention; 6 a current control means;
7 a PWM power converter; 8 a speed control means; 11 an AC synchronous motor (a
rotary motor or a linear motor); 12 a three-phase alternate current detector (CT);
13 an encoder; 14 a detected speed calculating means; 15 a compensated initial
magnetic pole position calculating means; 61 a 3/2 coordinate conversion calculating
means; 62 a subtractor (current error calculating means); 63 a current proportional
integral control unit; 64 a 2/3 coordinates conversion calculating means; 71 a
PWM gate pulse generator; 72 a triangular carrier wave; 73 a PWM invertor; 74
a direct current power supply; 81 a subtractor (speed deviation calculating means);
82 a speed gain control means; 101 a command speed pattern generating means; 102
a mode section determining means; 103 a speed integration gain processing means;
104 a mode switch; 1101 a first cyclic section (q-axis command current ←.
command torque, d-axis command current ← 0); 1102 a data acquisition speed
section determining means; 1103 a first command current calculating means; 1104
a first memory storing means; 1201 a second cyclic section (q-axis command current
← 0, d-axis command current ← command torque); 1202 a data acquisition
speed section determining means; 1203 a second command current calculating means;
1204 a second memory storing means; 105 a command speed end determining means;
106 a memory calling means; 106A an excessive data deviation determining means;
107 an estimated initial magnetic pole position calculating means; 108 a default
initial magnetic pole position setting means; and 109 a compensated initial magnetic
pole position calculating means.

Best Mode for Carrying Out the Invention

In the following, an embodiment of the present invention will be
described with reference to the drawings.

Fig. 1 is a general block diagram of a speed control including an
initial magnetic pole estimating apparatus directed by the present invention.

In Fig. 1, an AC motor 11 is driven by a current control means 6
and a PWM power converter 7 in accordance with a command torque. The AC synchronous
motor 11 is an AC rotary motor or an AC linear motor which does not have a magnetic
pole sensor (pole sensor).

A current detecting means 12 detects a current Ifb of the AC motor
11, and an electric angle detecting means (encoder) 13 detects a relative electric
angle (relative position) □ fb of the AC motor.

A detected speed calculating means 14 calculates a detected speed
□ fb from the detected electric angle □ fb detected by the electric angle
detecting means 13.

The initial magnetic pole estimating apparatus and method 1 according
to the present invention generate a command speed, calculates a command torque
in a speed control means 8 from information on the command speed and a detected
speed, and performs processing in accordance with the initial magnetic pole estimating
apparatus and method of the present invention from information on the command
torque to find an estimated initial magnetic pole position for an AC synchronous
motor.

Fig. 2 is a block diagram of a speed control based on a dq current
control (vector control) including an initial magnetic pole method for an AC synchronous
motor according to an embodiment of the present invention.

Figs. 3 - 4 are detailed block diagrams related to the initial magnetic
pole estimating method for an AC synchronous motor according to the embodiment
of the present invention.

Figs. 5 - 8 are diagrams related to command speed patterns having
a waveform over two cycles according to the embodiment of the present invention,
wherein Fig. 5 shows a command speed pattern of a trapezoidal wave; Fig. 6 shows
a command speed pattern of a triangular wave; Fig. 7 shows a command speed pattern
of a rectangular wave; and Fig. 8 shows a command speed pattern of a zero-speed
wave. It should be noted that while a command speed increase/decrease pattern
is arbitrary in an acceleration/deceleration section, a first-order increase/decrease
function is used here for purposes of description.

Fig. 9 is a diagram related to a mode switch in the detailed block
diagrams of the initial magnetic pole estimating method illustrated in Figs. 3
- 4.

Figs. 10 - 11 are flow charts related to the initial magnetic pole
estimating method for an AC synchronous motor according to the embodiment of the
present invention.

Sections for the command speed pattern over two cycles illustrated
in Figs. 5 - 8 are defined in the following manner.

(1) t10 - t20 is a first cyclic section, and t20 - t30 is a second cyclic section.
These are shown in Table 1.
First Cyclic Section Second Cyclic Section t10 - t20t20 - t30

(2) t10 - t11 is a zero speed start section; t14 - t15 is a pause section;
t18 - t22 is a mode switching section; t24 - t25 is a pause section; t28 - t30
is a zero speed end section. The foregoing sections are zero speed sections (comprised
of the zero speed start section, pause section, mode switching section, and zero
speed end section), and these sections are also referred to as the pause section.
These sections are shown in Table 2
Zero Speed Start Section Pause Section Mode Switching Section Zero speed End Section t10 - t11t14 - t15, t24 - t25t18 - t21t28 - t30

In each of the sections defined above, a trapezoidal basic waveform
(set time I) - applied waveforms (set time II - set time IV, and others) are contemplated
by performing time settings for the sections in accordance with applications.
These are shown in Table 5.
Command Speed Pattern Trapezoidal Wave Triangular Wave Rectangular Wave Zero-Speed Wave Fig. 5 Fig. 6 Fig. 7 Fig. 8 Set Time I Set Time II Set Time III Set Time IV Amplitude Value of Command Speed5050500 Zero Speed Start Section Time5ms5ms5ms5ms Zero Speed End Section Time5ms5ms5ms5ms Acceleration Section Time50ms50ms0ms50ms Deceleration Section Time50ms50ms0ms50ms Constant Speed Section Time500ms0ms500ms500ms Pause Section Time50ms50ms50ms50ms Mode Switching Section Time50ms50ms50ms50ms

Here, the times 5 ms, 50 ms, 500 ms are arbitrarily set values, and
a command speed amplitude value of 50 is an arbitrarily set value, the unit of
which is r/min (for a rotary motor) or mm/sec (for a linear motor).

The data acquisition speed section provided for acquiring data for
a magnetic pole estimation can be selected from a variety of sections shown in
Fig. 6 based on the command speed patterns defined above. These sections are shown
in Table 6.
(PART 1) Data Acquisition Speed Section Trapezoidal Wave Triangular Wave Rectangular Wave Zero-Speed Wave Positive Acceleration Sectiont11 - t12

Here, ○ indicates that the data acquisition speed section can be set, and ×
indicates that the section cannot be set.

The type of data acquired for magnetic pole estimation in the data
acquisition speed section can be set from the following three:

(1) First and Second Maximum Command Torques (First and Second Maximum Command
Current);

(2) First and Second Average Command Torques (First and Second Average Command
Current); and

(3) First and Second Instantaneous Command Torques (First and Second Instantaneous
Command Current).

The first command current and second command current can be selected
from a maximum command torque, an average command torque and an instantaneous command
torque in setting the type of data acquired for magnetic pole estimation, and
calculations for acquiring the respective data are performed in accordance with
the following equations (2) - (7):
I1max* = MAC(I1*[k]) I2max* = MAC(I2*[k]) I1ave* = Σ (I1*[k])/k I2ave* = Σ (I2* [k])/k I1inst*[k] = I1*[k] I2inst*[k] = I2*[k]
where I1max* and I2max* are a first and a second maximum command current;

I1ave* and I2ave* are a first and a second average command current;

I1inst*[k] and I2inst*[k] are a first and a second instantaneous
command current;

MAX is a function for calculating a maximum value; and

k is an arbitrary number of data.

In the following, the initial magnetic pole estimating method according
to the present invention will be described in an embodiment based on a dq current
control and the following settings:

(1) Setting 1: Command Speed over Two Cycles ⇒ Command Speed Pattern of
Trapezoidal Wave;

(2) Setting 2: Data Acquisition Speed Section ⇒ Positive Constant Speed
Section; and

(3) Setting 3: Data Acquired for Magnetic Pole Estimation ⇒ Maximum Command
Torque (Maximum Command Current)

The embodiment of the present invention performs the initial magnetic
pole estimating method illustrated in Fig. 3 in a speed control loop in a dq current
control means for an AC synchronous motor illustrated in Fig. 2.

The dq current control for an AC synchronous motor comprises a configuration
except for the AC synchronous motor 11 in Fig. 1. Specifically, the AC synchronous
motor 11 is driven by a PWM power converting means 72 for converting a direct
current voltage 74 into an arbitrary alternate current voltage, a three-phase current
of the AC synchronous motor is detected by a three-phase current detector 12,
a relative electric current of the AC synchronous motor is detected by an electric
angle detector 13, a three-phase/two-phase coordinate conversion is performed
by a three-phase/two-phase coordinate conversion calculating means 61 from the
detected three-phase current to a detected two-phase current using information
on the electric angle. A detection speedω is calculated by a detected speed
calculating means 14 using a detected electric angle &thetas; . The detected two-phase
current is subtracted from a two-phase command current to calculate a current error
in a current error calculating means 62, the current error is multiplied by a
two-phase proportional integral gain to calculate a two-phase command voltage in
a two-phase current proportional integral control unit 63, and a two-phase/three-phase
coordinate conversion is performed in a two-phase/three-phase coordinate conversion
calculating means 64 from the two-phase command voltage to a three-phase command
voltage using the information on the electric angle. The three-phase command voltage
is compared with a triangular carrier waver 72 to calculate PWM gate pulses in
a PWM gate pulse generating means 71, and these pulses are outputted to the PWM
invertor 73.

As a next step, a trapezoidal command speed pattern is generated
in a command speed pattern generating means 101, a detected speed is subtracted
from the command speed to calculate a speed deviation in a speed deviation calculating
means 81, and the speed deviation is multiplied by a speed gain to calculate a
command torque (command current) in a speed gain control unit 82.

A mode section determining means 102 determines a mode section for
a first cyclic section and a second cyclic section from the trapezoidal command
speed, and a mode section switching operation is performed in a mode switch 104
in accordance with the determination result.

For switching from the first cyclic section to the second cyclic
section (an operation in which a command current calculated by the speed control
means is switched from an input to a q-axis command current to an input to a d-axis
command current), the switching is performed without fail in a mode switching section
which is a zero-speed section. This is because a defective operational phenomenon
is more likely to occur due to a component accumulated by a speed integration gain
(integration term) when the mode is switched in a section (for example, an acceleration/deceleration
section, a constant speed section) other than the zero-speed section. Specifically,
the mode is switched by the mode switch within t17 - t20. Also, the integration
term of the speed integration gain is cleared at an instance the mode is switched
by the mode switch.

When the first cyclic section is selected, a command torque (command
current) calculated in the speed gain control unit is inputted to a q-axis command
current, while zero is inputted to a d-axis command current.

An acceleration section determining means 1102 determines whether
or not a command speed is a positive acceleration section. A first maximum command
torque (first maximum command current) is calculated from a certain command torque
in the determined section, and stored in a memory by a first memory storing means
1104.

When the second cyclic section is selected, zero is inputted to the
q-axis command current, and a command torque (command current) calculated in the
speed gain control unit is inputted to the d-axis instruction current.

An acceleration section determining means 1202 determines whether
or not a command speed is a positive acceleration section. A second maximum command
torque (second maximum command current) is calculated from a certain command torque
in the determined section, and stored in a memory by a second memory storing means
1204.

Subsequent to the second cyclic section (t30 -) of the command speed,
the first maximum command current data and second maximum command current data
stored in the memories are called from the memories by a memory calling means
106, and an excessive data deviation determining means 106A determines excessive
data from the called first command current data and second command current data.
Subsequently, an estimated initial magnetic pole position &thetas; est is calculated
in an estimated initial magnetic pole calculating means 107 of Equation (8) from
information on the called first command current data and second command current
data. However, the first and second command current data (I1data*, I2data*), when
stored in the memories, have the same values as the called first and second command
current data (I1data*call, I2data*call).

(1) Routine I of Memory: I1data* → Memory → I2data*call;

(2) Routine II of Memory: I2data* → Memory → I2data*call.

where &thetas; est is an estimated initial magnetic pole position;

FNC is an arbitrary function;

I1data* is the first command current data (first command torque
data); and

I2data* is the second command current data (second command torque
data).

Finally, a compensated initial magnetic pole calculating means 109
using Equation (9) adds the estimated initial magnetic pole position &thetas; est
to a default initial magnetic pole position &thetas; 0 set by a default initial
magnetic pole position setting means 108 to calculate a compensated initial magnetic
pole position &thetas; comp:
&thetas; comp = &thetas; 0 + &thetas; est
where &thetas; comp is the compensated initial magnetic pole position; and

&thetas; 0 is the default initial magnetic pole position (arbitrary
value) in the initial settings.

When the first command current data and second command current data
used in the calculation of the estimated initial magnetic pole position are a maximum
command current, an average command current, and an instantaneous command current,
the estimated initial magnetic pole position &thetas; est (&thetas; estmax, &thetas;
estave, &thetas; estinst) is calculated by the following Equations (10) - (12)
:
&thetas; estmax = tan^{- 1}(I1max*/I2max*) &thetas; estave = tan^{- 1}(I1ave*/I2ave*) &thetas; estinst = Σ (tan^{- 1}(I1inst*[k]/I2inst*[k]))/k

Fig. 12 is a flow chart for determining a region of a torque axis
or a magnetic flux axis in accordance with the embodiment of the present invention.

Fig. 13 is a flow chart related to a "subroutine for determining
the direction of the torque axis" at S108 in the flow chart of Fig. 12.

Fig. 14 is a flow chart continued from a position (A) in the flow
chart of Fig. 13.

Fig. 15 is a diagram in which 360 degrees are divided into eight
for representing respective directions in accordance with the embodiment of the
present invention.

A procedure for the aforementioned initial magnetic pole estimation
calculating means is shown as follows, including the processing for determining
the direction of the torque axis of the AC synchronous motor.

First, the direction (region) of the torque axis is determined in
the following manner with reference to the flow chart of Fig. 12.

<Main Routine for Determining Direction (Region) of Torque Axis>

S100: Set a default initial magnetic pole position (currently set initial magnetic
pole position) to zero. Also, set a safe_area determination flag to zero. Go to
S101.

S101: Input a first cyclic period of a waveform generated by a command speed
waveform generating means as a shaft determining command speed pattern. Go to S102.

S102: Subtract a detected speed from a shaft determining command speed in the
speed deviation calculating means. Go to S103.

S103: Multiply the speed deviation by a speed proportional integral gain to
calculate a command torque (command current) in the speed proportional integral
control unit. However, clear an integration term of a speed integration gain at
an instance the direction of the torque axis is switched. Go to S104.

S104; Input a command torque (command current) to a q-axis command current,
and input zero to a d-axis command current. Go to S105.

S105: Go to S107 if the result given by the excessive speed deviation determining
means shows "Speed Deviation ≥ Speed Deviation Limit Level." Otherwise, go
to S106.

S106: Go to S108 if a command speed terminates. Otherwise, go to S101.

S107: Substitute one into sp_err. Go to S108.

S108: Determine a direction in which the command torque (command current) is
supplied by a "subroutine for determining the direction of the torque axis." Go
to S109.

S109: If the safe_area determination flag is zero, go to S110. If one, go to
S111.

S110: Input again the command speed from the beginning. Go to S101.

S111: Go to step 1 in an "initial magnetic pole estimation routine."

<Subroutine for Determining Direction of Torque Axis>

F1: Assume that the torque axis of the AC synchronous motor exists in a direction
(1) in Fig. 15 (set □ 0 to zero degrees). If O.K., go to F11. If N.G., go to
F12.

F10: Assume that the torque axis exists in a direction (4) in Fig. 15 (set
&thetas; 0 to 135 degrees) . If O.K., go to F101. If N.G., go to F102.

F11: Assume that the torque axis exists in a direction (8) in Fig. 15 (set
&thetas; 0 to 315 degrees) . If O.K., go to F111. If N.G., go to F112.

F12: Set immediately the torque axis determining command speed to zero, and
do nothing until the next shaft determining command speed. Go to F10.

F100: Assume that the torque axis exists in a direction (5) in Fig. 15 (set
&thetas; 0 to 180 degrees) . If O.K., go to F1001. If N.G., go to F1012.

F101: Assume that the torque axis exists in a direction (3) in Fig. 15 (set
&thetas; 0 to 90 degrees) . If O.K., go to F1011. If N.G., go to F1012.

F102: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (6) in Fig. 15 (set &thetas; 0 to 225
degrees) until the next shaft determining command speed. Go to F100 when the next
shaft determining command speed is supplied.

F110: Assume that the torque axis exists in a direction (3) in Fig. 15 (set
&thetas; 0 to 90 degrees), and set the safe_area determination flag to one.

F111: Assume that the torque axis exists in a direction (7) in Fig. 15 (set
&thetas; 0 to 270 degrees) . If O.K., go to F1111. If N.G., go to F1112.

F112: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (2) in Fig. 15 (set &thetas; 0 to 45
degrees) until the next shaft determining command speed. Go to F110 when the next
shaft determining command speed is supplied.

F1000: Assume that the torque axis exists in a direction (8) in Fig. 15 (set
&thetas; 0 to 315 degrees), and set the safe_area determination flag to one.

F1001: Assume that the torque axis exists in a direction (7) in Fig. 15 (set
&thetas; 0 to 270 degrees), and set the safe_area determination flag to one.

F1002: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (7) in Fig. 15 (set &thetas; 0 to 270
degrees) until the next shaft determining command speed. Go to F1000 when the
next shaft determining command speed is supplied.

F1010: Assume that the torque axis exists in a direction (6) in Fig. 15 (set
□ 0 to 225 degrees), and set the safe_area determination flag to one.

F1011: Assume that the torque axis exists in a direction (2) in Fig. 15 (set
&thetas; 0 to 45 degrees) . If O.K., go to F10111. If N.G., go to F10112.

F1012: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (5) in Fig. 15 (set &thetas; 0 to 180
degrees) until the next shaft determining command speed. Go to F1010 when the
next shaft determining command speed is supplied.

F1110: Assume that the torque axis exists in a direction (2) in Fig. 15 (set
&thetas; 0 to 45 degrees), and set the safe_area determination flag to one.

F1111: Assume that the torque axis exists in a direction (1) in Fig. 15 (set
&thetas; 0 to 0 degrees), and set the safe_area determination flag to one.

F1112: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (1) in Fig. 15 (set &thetas; 0 to 0
degrees) until the next shaft determining command speed. Go to F1110 when the
next shaft determining command speed is supplied.

F10110: Assume that the torque axis exists in a direction (5) in Fig. 15 (set
&thetas; 0 to 180 degrees), and set the safe_area determination flag to one.

F10111: Assume that the torque axis exists in a direction (4) in Fig. 15 (set
&thetas; 0 to 135 degrees), and set the safe_area determination flag to one.

F10112: Set immediately the shaft determining command speed to zero, and assume
that the torque axis exists in a direction (4) in Fig. 15 (set &thetas; 0 to 135
degrees) until the next shaft determining command speed. Go to F10110 when the
next shaft determining command speed is supplied.

<Initial Magnetic Pole Estimation Routine>

Step 1: Set the default initial magnetic pole position &thetas; 0 as an arbitrary
angle (E101).

Step 1A: Set a data deviation limit level (E101A).

Step 2: Set a command speed pattern (an amplitude value of a command speed,
an acceleration section time, a constant speed section time, a pause section time,
a mode switching section time) in the command speed pattern generating means,
and generate an optimal command speed pattern (trapezoidal wave, triangular wave,
rectangular wave, zero-speed wave, sinusoidal wave) for an application field to
which it is applied (E102, E105).

Step 3: Set a data acquisition speed section (see Table 2) and data acquired
for magnetic pole estimation in the data acquisition speed section (maximum command
current, average command current, instantaneous command current) based on the
command speed pattern generated at E102 (E103, E104).

Step 4: Subtract a detected speed from the command speed to calculate a speed
deviation (E106).

Step 5: Multiply the speed deviation by a speed gain (any of a speed proportion
gain, a speed proportion integration gain, and a speed integration gain) to calculate
a command torque (command current) (E107).

Step 6: Determine a mode section (the first cyclic section and second cyclic
section) from the command speed in the mode section determining means, and perform
a switching operation from the first cyclic section to the second cyclic section
in accordance with the result in the mode switch (E109).

Perform processing associated with an integration term of the speed integration
gain (the integration term is cleared, held or the like) in a speed integration
processing means at an instance the mode switching is performed by the mode switch
(E108).

Step 7: Perform operations from step 8A to step 8C (E1101 - E1104) in the first
cyclic period found at E109, or perform the operations from step 9A to step 9C
(E1201 - E1205) in the second cyclic section found at E107.

Step 8A: Input the command torque (command current) calculated at step 5 to
the q-axis command current, and input zero to the d-axis command current (E1101).

Step 8B: Determine whether the command speed is a data acquisition speed section,
and calculate first command current data (first command torque data) from the
command torque in the determined section (E1102, E1103).

Step 8C: Store the first command current data in a memory by the first memory
storing means (E1104).

Step 9A: Input zero to the q-axis command current, and input the command torque
(command current) calculated at step 5 to the d-axis command current (E1201).

Step 9B: Determine whether the command speed is a data acquisition speed section,
and calculate second command current data (second command torque data) from the
command torque in the determined section (E1202, E1203).

Step 9C: Store the second command current data in a memory by the second memory
storing means (E1204).

Step 10: Call the first and second command current data from the memories after
the end of the second cyclic section of the command speed (E1205) (E110).

Step 11: Calculate the difference between the first command current data and
second command current data called at E110 as a data deviation (E110A).

Step 12: Compare the data deviation with a data deviation limit level, and
when the result shows "data deviation ≥ data deviation limit level," calculate
again from E105 after a change to a predefined phase (E110B, E110C).

STep 12A: Compare the data deviation with a data deviation limit level, and
when the result shows "data deviation < data deviation limit level," calculate
an estimated initial magnetic pole position in the estimated initial magnetic
pole calculating means using Equation (8), using the first command current data
and second command current data called at E110 (E111).

Step 13: Add the estimated initial magnetic pole position &thetas; est to the
default initial magnetic pole position &thetas; 0 to calculate a compensated initial
magnetic pole position &thetas; comp in the compensated initial magnetic pole
calculating means using Equation (9) (E112).

As described above, according to the embodiment of the present invention,
the following effects are produced: 1) a correct initial magnetic pole position
estimation can be accomplished in a short estimation time; 2) a maximum torque
can be generated while minimizing a torque loss; and 3) a range in which the motor
moves can be minimized.

Industrial Applicability

As described above, according to the present invention, the following
effects are produced:

1) a correct initial magnetic pole position estimation can be accomplished
in a short estimation time;

2) a maximum torque can be generated while minimizing a torque loss; and

3) a range in which the motor moves can be minimized.

Anspruch[en]

An initial magnetic pole estimating apparatus for an AC synchronous motor,
equipped in an AC synchronous motor controller comprising speed control means for
calculating a command torque (command current) from a command speed, current control
means for driving the AC synchronous motor in accordance with the command torque
(command current), and a PWM power converter, said initial magnetic pole estimating
apparatus characterized by having:

speed deviation calculating means for subtracting a detected speed from said
command speed generated by command speed pattern generating means to calculate
a speed deviation;

a speed gain control unit for multiplying said speed deviation by a speed gain
to calculate a command torque (command current);

mode section determining means for determining a mode section (a first cyclic
section and a second cyclic section) from said command speed;

a mode switch for switching a mode section to any of said first cyclic section
and said second cyclic section in accordance with a result in said mode section
determining means;

data acquisition speed section determining means for determining whether said
command speed is in a data acquisition speed section when said first cyclic section
is selected;

a first command torque calculating means (first command current calculating
means) for calculating first command torque data (first command current data) from
said command torque (said command current) in said determined data acquisition
speed section;

data acquisition speed section determining means for determining whether said
command speed is in said data acquisition speed section when said second cyclic
section is selected;

second command torque calculating means (second command current calculating
means) for calculating second command torque data (second command current data)
from said command torque (said command current) in said determined data acquisition
speed section; and

estimated initial magnetic pole calculating means for calculating an estimated
initial magnetic pole position using information on said first command torque
data (said first command current data) and said second command torque data (said
second command current data).

An initial magnetic pole estimating apparatus for an AC synchronous motor equipped
in an AC synchronous motor controller comprising:

PWM power converting means for converting a direct current voltage to an arbitrary
alternate current voltage to drive the AC synchronous motor;

three-phase current detecting means for detecting a three-phase current of
said AC synchronous motor;

an electric angle detecting means for detecting a relative electric angle of
said AC synchronous motor;

three-phase/two-phase coordinate conversion calculating means for performing
a three-phase/two-phase coordinate conversion from a detected three-phase current
to a detected two-phase current using said detected electric angle;

detected speed calculating means for calculating a detected speed from said
detected electric angle;

two-phase current error calculating means for subtracting said detected two-phase
current from a two-phase command current comprised of a q-axis command current
and a d-axis command current to calculate a current error;

a two-phase current proportion integration control unit for multiplying said
current error by a two-phase current proportion integration gain to calculate a
two-phase command voltage;

two-phase/three-phase coordinate conversion calculating means for performing
a two-phase/three-phase coordinate conversion from said two-phase command voltage
to a three-phase command voltage using said detected electric angle; and

PWM gate pulse calculating means for comparing said three-phase command voltage
with a carrier waver to calculate a PWM gate pulse and outputting said PWM gate
pulse to said PWM power converting means,

said initial magnetic pole estimating apparatus for an AC synchronous motor
characterized by having:

default initial magnetic pole setting means for setting a default initial magnetic
pole position to zero;

command speed pattern generating means for generating a command speed as a
two-cycle waveform;

speed deviation calculating means for subtracting said detected speed from
said command speed to calculate a speed deviation;

a speed gain control unit for multiplying said speed deviation by a speed gain
to calculate a command torque (command current);

mode section determining means for determining a mode section (a first cyclic
section and a second cyclic section) from said command speed;

a mode switch for switching a mode section to any of said first cyclic section
and said second cyclic section in accordance with a result in said mode section
determining means;

acceleration section determining means for inputting said command torque (said
command current) to said q-axis command current and inputting zero to said d-axis
command current, when said first cyclic section is selected, and determining whether
or not said command speed is in a positive acceleration section;

first command torque calculating means (first command current calculating means)
for calculating first maximum command torque data (first maximum command current
data) from said command torque which is said determined positive acceleration
section;

first memory storing means for storing said first maximum command torque in
a memory;

acceleration section determining means for inputting zero to said q-axis command
current and inputting said command torque (said command current) to said d-axis
command current when said second cyclic section is selected, and determining whether
or not said command speed is in a positive acceleration section;

second command torque calculating means (second command current calculating
means) for calculating second maximum command torque data (second maximum command
current data) from said command torque which is in said determined positive acceleration
section;

second memory storing means for storing said second maximum command torque
in a memory;

estimated initial magnetic pole calculating means for calling said maximum
command torques (first and second maximum command torques) from said memories after
said command speed has terminated a second cycle to calculate an estimated initial
magnetic pole position using said information; and

compensated initial magnetic pole calculating means for adding said estimated
initial magnetic pole position to said default initial magnetic pole position to
calculate a compensated initial magnetic pole position.

An initial magnetic pole estimating apparatus for an AC synchronous motor equipped
in an AC synchronous motor controller comprising:

PWM power converting means for converting a direct current voltage to an arbitrary
alternate current voltage to drive the AC synchronous motor;

three-phase current detecting means for detecting a three-phase current of
said AC synchronous motor;

an electric angle detecting means for detecting a relative electric angle of
said AC synchronous motor;

detected speed calculating means for calculating a detected speed from said
detected electric angle;

three-phase command current calculating means for calculating three-phase command
current comprised of a A-phase command current, a B-phase command current and a
C-phase command current from a command torque (command current) using said detected
electric angle;

three-phase current error calculating means for subtracting said detected three-phase
current from a three-phase command current to calculate a current error;

a three-phase current proportion integration control unit for multiplying said
current error by a three-phase current proportion integration gain to calculate
a three-phase command voltage; and

PWM gate pulse calculating means for comparing said three-phase command voltage
with a carrier waver to calculate a PWM gate pulse and outputting said PWM gate
pulse to said PWM power converting means,

said initial magnetic pole estimating apparatus for an AC synchronous motor
characterized by having:

default initial magnetic pole setting means for setting a default initial magnetic
pole position to zero;

command speed pattern generating means for generating a command speed as a
two-cycle waveform;

speed deviation calculating means for subtracting said detected speed from
said command speed to calculate a speed deviation;

a speed gain control unit for multiplying said speed deviation by a speed gain
to calculate a command torque (command current);

mode section determining means for determining a mode section (a first cyclic
section and a second cyclic section) from said command speed;

a mode switch for switching a mode section to any of said first cyclic section
and said second cyclic section in accordance with a result in said mode section
determining means;

three-phase command current converting means operative when said first cyclic
section is selected for adding a shift angle equal to zero degrees to said detected
electric angle (without phase change), and calculating said three-phase command
current from said command torque (said command current);

acceleration section determining means for determining whether or not said
command current is in a positive acceleration section;

first command torque calculating means (first command current calculating means)
for calculating a value of a first maximum command torque (first maximum command
current) from said command torque which is in said determined positive acceleration
section;

first memory storing means for storing said first maximum command torque in
a memory;

said three-phase command current converting means operative when said second
cyclic section is selected for adding a shift angle equal to 90 degrees to said
detected electric angle (a phase change by 90 degrees), and thereafter calculating
said three-phase command current from said command torque (said command current);

acceleration section determining means for determining whether or not said
command speed is in a positive acceleration section;

second command torque calculating means (second command current calculating
means) for calculating a value of a second maximum command torque (second maximum
command current) from said command torque which is in said determined positive
acceleration section;

second memory storing means for storing said second maximum command torque
in a memory;

estimated initial magnetic pole calculating means for calling said maximum
command torques (first and second maximum command torques) from said memories after
said command speed has terminated a second cycle to calculate an estimated initial
magnetic pole position using said information; and

compensated initial magnetic pole calculating means for adding said estimated
initial magnetic pole position to said default initial magnetic pole position to
calculate a compensated initial magnetic pole position.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said command speed pattern
generating means is capable of arbitrarily setting an acceleration/deceleration
section time and a constant speed section time, arbitrarily setting a speed waveform
in the acceleration/deceleration section, and arbitrarily setting an amplitude
value for a command speed to generate said command speed as a trapezoidal wave,
a triangular waver, a rectangular wave, a zero-speed wave, a sinusoidal wave,
and the like as a two-cycle waveform.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said speed gain control
unit functions as a speed proportion control unit, a speed proportion integration
control unit or a speed integration control unit in a combination of a speed proportion
control unit and a speed integration control unit.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said current control means
is a dq current control means (vector current control meas), or three-phase current
control means.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that in said dq current control
means used as said current control means, said command current is inputted to
the q-axis command current, and a constant value is inputted to the d-axis command
current in said first cyclic section, and said command current is inputted to
the d-axis command current, and a constant value is inputted to the q-axis command
current in said second cyclic section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1- 7, characterized in that said constant value is
an arbitrary number.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that in said three-phase current
control means used as said current control means, in said first cyclic section,
after a shift angle equal to zero degrees is added to said detected electric angle
(without phase change), said command torque (said command current) is converted
to a three-phase command current as shown in the following equations, and in said
second cyclic section, after a shift angle equal to 90 degrees is added to said
detected electric angle (phase change by 90 degrees) , said command torque (said
command current) is converted to a three-phase command current as shown in the
following equations.
Ia* = I* x cos( &thetas; fb -&thetas; shift) Ib* = I* x cos ( &thetas; fb - &thetas; shift - 120 degrees) Ic* = I* x cos ( &thetas; fb - &thetas; shift - 240 degrees)
where I* is a command torque (command current);

&thetas; fb is a detected electric angle (relative position);

&thetas; shift is a shift angle (zero degrees in the first cyclic
section, and 90 degrees in the second cyclic section);

Ia* is an A-phase command current;

Ib* is a B-phase command current; and

Ic* is a C-phase command current.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that in said current control
means, said command torque (said command current) is treated as said command current
in said first cyclic section after a shift angle equal to zero degrees is added
to said detected electric angle (without phase change), and said command torque
(said command current) is treated as said command current in said second cyclic
section after a shift angle equal to 90 degrees is added to said detected electric
angle (phase change by 90 degrees).

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said data acquisition
speed section is comprised of a combination of a positive acceleration section,
a negative acceleration section, a positive deceleration section, a negative deceleration
section, a positive constant speed section, and a negative constant speed section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said data acquisition
speed section determining means is acceleration section determining means when
said magnetic pole estimating data is acquired in an acceleration section; constant
speed section determining means when acquired in a constant speed section; acceleration/constant
speed section determining means when acquired in an acceleration section and a
constant speed section; deceleration/constant speed section determining means when
acquired in a deceleration section and a constant speed section; acceleration/deceleration
determining means when acquired in an acceleration section and a deceleration
section; and an acceleration/deceleration/constant speed section determining means
when acquired in an acceleration section, a deceleration section and a constant
speed section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that when said data acquisition
speed section determining means is said constant speed section determining means,
said magnetic pole estimating data is calculated after said arbitrary time set
due to the fact that it can be set from zero to an arbitrary time (however, said
arbitrary time is smaller than an end time of said constant speed section) until
the end time of said constant speed section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by having:

first memory storing means for storing said first command current data calculated
in the first cyclic section in a memory; and

second memory storing means for storing said second command current data calculated
in the second cyclic section in a memory.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by calling said command torque
data (first and second command torque data) from said memory.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said estimated initial
magnetic pole position is calculated as expressed by tan^{- 1} (said first
command current data/said second command current data), or a combination of cos^{-
1} and sin^{- 1}, or said estimated initial magnetic pole position
is calculated as expressed by Σ(tan^{- 1} (said first instantaneous
command current data/said second instantaneous command current data))/k when said
first and second command current data are instantaneous command currents, or calculated
from a relationship between said first command current data and said second command
current data.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said first command current
data and second command current data calculated by said first command current
calculating means and said second command current calculating means are a maximum
command current, an average command current and an instantaneous command current,
wherein the maximum command current is a maximum value calculated from a command
current which is in said data acquisition speed section, the average command current
is an average of the command current which is in said data acquisition speed section,
and the instantaneous command current is a command current which is an instantaneously
calculated command current which is in said data acquisition speed section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that in said command speed,
a pause section in which said command speed has a zero command speed is provided
when switching between positive and negative, and a time for said pause section
can be arbitrarily set.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that in said command speed,
a pause section in which said command speed is zero is provided between a first
cyclic section in a first cycle and a second cyclic section in a second cycle,
and a section is switched during the pause section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said command current,
a pause section is provided when a forced phase change is performed, and said
phase change is performed in said pause section.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by having speed integration gain
processing means for performing speed integration gain processing (clearing, holding
and the like of an integration term) of said speed gain control unit, when the
first cyclic section is switched to the second cyclic section, or when a forced
phase change is performed, in said command current.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that an axial direction determining
command speed provided for determining a direction (region) of a torque axis or
a magnetic flux axis of said AC synchronous motor uses a first cyclic waveform
of the command speed according to claim 4.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that a user sets one or more
of a speed deviation limit level, a torque limit level, a speed limit level, and
a data deviation limit level in a parameter setting memory within said initial
magnetic pole estimating apparatus for an AC synchronous motor.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that excessive speed deviation
determining means compares a speed deviation calculated by subtracting said detected
speed from said axial direction determining command speed with said speed deviation
limit level to determine an excessive speed deviation of the motor.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that excessive torque determining
means compares a command torque supplied from said speed control unit with said
torque limit level to determine an excessive command torque for the motor.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that excessive speed determining
means compares said detected speed with said speed limit level to determine an
excessive speed for the motor.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by dividing 360 degrees of electric
angle by a certain positive integer n, assuming that said torque axis exists
in a certain direction within 360 degrees, controlling said AC synchronous motor
with an axial direction determining command speed, determining an excessive speed
deviation in said excessive speed deviation determining means, and estimating a
direction of said torque axis from the determination result.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by assuming that said torque axis
of the AC synchronous motor is in another direction in accordance with the result
of the excessive speed deviation determination, and estimating the direction of
the torque axis of said AC synchronous motor by repeating said operation of controlling
said AC synchronous motor with the axial direction determining command speed, and
determining the excessive speed deviation in said excessive speed deviation determining
means by a predefined subroutine.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by estimating the direction of
the torque axis of said AC synchronous motor in the axial direction determining
means according to any one of claims 22 - 28, and thereafter estimating an initial
magnetic pole position of said AC synchronous motor in the calculation processing.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that excessive data deviation
determining means compares a difference between said first command torque data
and said second command torque data (data difference) with said data deviation
limit level to determine an excessive data deviation.

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized by determining an excessive data
deviation in said excessive data deviation determining means, and estimating an
initial magnetic pole position of said AC synchronous motor again by the calculation
processing according to claim 1, 2 or 3 after changing to a predefined phase,
when the determination result shows "data deviation ≥ data deviation limit level."

An initial magnetic pole estimating apparatus for an AC synchronous motor according
to any one of claims 1 - 3, characterized in that said AC synchronous motor
is a rotary motor or a linear motor.