JP2001045800A - Method for controlling synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously measure the constant of an electric motor by allowing an AC current to flow to a d-axis when the estimation of the direction of a permanent magnet is completed, allowing an AC current with a phase being different by 90 degrees and with an equal amplitude to flow to a q-axis, and obtaining the inductance of both the axes of the electric motor and the resistance component for setting and storing. SOLUTION: An electric motor constant-calculating means 8 inputs a d-axis current id, a q-axis current iq, a d-axis voltage vd, and a q-axis voltage vd, and outputs a control signal S5 where an AC current flows as the d-axis current and an AC current with a phase being different by 90 degrees and with an equal amplitude flows as the q-axis current. Then, Fourier transform is made, thus obtaining a d-axis inductance Ld, a resistance component Rd, and a q-axis inductance Lq, a resistance component Rq. Also, a setting storage means 9 inputs the inductance, resistance components, and the magnetic flux of a permanent magnet, sets and stores the average value of the resistance components Rd and Rq as armature resistance R, and sets and stores the inductance Ld and Lq of both the axes and the magnetic flux of the permanent magnet, thus performing setting to a control device without using a device for measuring the constant of the electric motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for controlling a permanent magnet type synchronous motor, and more particularly to a synchronous motor which can be easily adjusted with high accuracy without using a position sensor or a speed sensor. In the control method.

[0002]

2. Description of the Related Art Conventionally, a winding resistance which is a motor constant of a permanent magnet type synchronous motor is measured by a DC test, and an inductance Ld of a d-axis is limited to a d-axis current only when the permanent magnet type synchronous motor is fixed. Measured by a restraint test with alternating current, q
The inductance Lq of the shaft is measured by a constraint test in which an AC current is applied only to the q-axis current with the permanent magnet type synchronous motor fixed, the magnetic flux of the permanent magnet is measured by a load test, and the measured motor constant is manually measured. Input to the control unit.

[0003]

In order to control a permanent magnet synchronous motor with high accuracy, a value of a motor constant of the permanent magnet synchronous motor may be required. However, for example, when measuring the inductance Ld of the d-axis and the inductance Lq of the q-axis, a tool for fixing the permanent magnet type synchronous motor so that it does not rotate is necessary. Could not be controlled with high precision. Further, since the armature resistance, the inductance Ld on the d-axis, and the inductance Lq on the q-axis are measured separately, there is a problem that it takes time and effort.

When measuring the d-axis inductance Ld and the q-axis inductance Lq, a position detector for detecting the direction of the permanent magnet is required. Further, when measuring the magnetic flux of the permanent magnet, a position detector for detecting the direction of the permanent magnet and a speed detector for detecting the rotational speed of the permanent magnet synchronous motor are required. These position and speed detectors limit the use of vibration, dust, temperature, etc., increase the motor volume,
Further, there are problems such as disconnection of the detector signal line and noise mixing. The present invention has been made in view of such a point,
It is an object of the present invention to solve these drawbacks and to provide a synchronous motor control method capable of simultaneously measuring a motor constant without using a position detector, a speed detector, and a test device.

[0005]

In order to achieve the object, a primary current flowing through a permanent magnet type synchronous motor is defined by a d-axis current component parallel to an estimated direction of the permanent magnet. In a control method of a synchronous motor that performs control by dividing the current into a q-axis current component perpendicular to the d-axis, an alternating current is passed as a d-axis current while the permanent magnet synchronous motor is stopped, and a q-axis current is applied to the d-axis current. An alternating current having a 90 degree phase difference and equal amplitude is passed, and the amplitude of the d-axis voltage and the amplitude of the q-axis voltage are compared. If the amplitude of the d-axis voltage is larger than the amplitude of the q-axis voltage, the estimated direction of the permanent magnet is determined. Is advanced or delayed by 90 degrees, the q-axis current is not passed, the AC current is passed as the d-axis current, the direction of the permanent magnet estimated by the product of the differential value of the q-axis voltage and the d-axis current is corrected, and the q-axis is corrected. No current flows, d
When an alternating current is applied to the axis current, the direction of the permanent magnet estimated when the average value of the d-axis voltage when the d-axis current is positive is larger than the average value of the d-axis voltage when the d-axis current is negative is When the direction of the permanent magnet is estimated by 180 degrees, an alternating current is supplied as a d-axis current at the time when the estimation of the direction of the permanent magnet is completed. From the magnitude and phase of the axis current and the magnitude and phase of the d-axis voltage, the d-axis inductance Ld and the resistance component Rd of the permanent magnet synchronous motor are obtained and set and stored, and the magnitude and phase of the q-axis current and the magnitude of the q-axis voltage are obtained. The q-axis inductance Lq and the resistance component Rq of the permanent magnet synchronous motor are obtained from the phase and set and stored.

Further, the average value of the resistance component Rd and the resistance component Rq is set and stored as the armature resistance R of the permanent magnet type synchronous motor.

Further, an alternating current is applied as a d-axis current, and q
When a DC current is passed as the axis current and the permanent magnet synchronous motor is rotating, the direction of the permanent magnet and the rotation speed of the permanent magnet synchronous motor are estimated from the d-axis current, the q-axis current and the q-axis voltage, Armature resistance R, d-axis inductance Ld,
q-axis inductance Lq, estimated permanent magnet direction,
The estimated rotational speed, d-axis current, q-axis current, and q-axis voltage are input, and the magnetic flux of the permanent magnet is determined and set and stored.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention, wherein 1 is a permanent magnet synchronous motor, 4 is a power converter for supplying electric power to the permanent magnet synchronous motor 1, and 2 is applied to the permanent magnet synchronous motor 1. A voltage detector 3 for detecting the primary voltage v1 is a primary current i flowing through the permanent magnet type synchronous motor 1.
This is a current detector for detecting the value “1”. Reference numeral 6 denotes a torque controller that inputs a d-axis inductance Ld, a q-axis inductance Lq, an armature resistance R, and a magnetic flux φ of a permanent magnet, and outputs a control signal S1 necessary for controlling the torque of the permanent magnet synchronous motor 1. It is.

The current component converter 13 receives the primary current i1 and the estimated direction θg of the permanent magnet and inputs the d-axis current id.
And q-axis current iq. The voltage component converter 14
The d-axis voltage vd and the q-axis voltage vq are output by inputting the primary voltage v1 and the estimated direction θg of the permanent magnet. position·
The speed estimating means 7 controls the control signal S2 such that an alternating current flows as the d-axis current id and an alternating current having a phase difference of 90 degrees with respect to the d-axis current and equal amplitude flows as the q-axis current.
A control signal S3 such that an AC current flows as a d-axis current id without flowing a q-axis current, a d-axis current i without flowing a q-axis current iq
As d, the control signal S4 for causing a large AC current to flow so as to cause magnetic saturation, the estimated rotation speed ωg, and the estimated permanent magnet direction θg are output. Details will be described later.

The motor constant calculating means 8 calculates the d-axis current id,
The q-axis current iq, the d-axis voltage vd, and the q-axis voltage vq are input, an alternating current flows as the d-axis current id, and the q-axis current iq
And outputs a control signal S5 such that an alternating current having a phase different from that of the d-axis current id by 90 degrees and having the same amplitude flows, and the d-axis current id, the q-axis current iq, the d-axis voltage vd, and the q-axis voltage vq
Is Fourier-transformed, the d-axis inductance Ld and the resistance component Rd are obtained from the magnitude and phase of the fundamental component of the d-axis current id and the magnitude and phase of the fundamental component of the d-axis voltage vd, and the fundamental component of the q-axis current iq is obtained. Magnitude and phase and q-axis voltage vq
From the magnitude and phase of the fundamental wave component of
q and the resistance component Rq are obtained.

The magnetic flux calculating means 10 includes a d-axis current id, a q-axis current iq, a q-axis voltage vq, a d-axis inductance Ld, q
The shaft inductance Lq, the armature resistance R, the estimated direction θg of the permanent magnet, and the estimated rotation speed ωg are input, and an alternating current flows as a d-axis current id, and a q-axis current iq
The control signal S6 and the magnetic flux φ of the permanent magnet are output such that a DC current flows. The setting storage means 9 includes a d-axis inductance Ld, a q-axis inductance Lq, and a resistance component R
d, the resistance component Rq and the magnetic flux φ of the permanent magnet are inputted, the average value of the resistance component Rd and the resistance component Rq is set and stored as the armature resistance R, and the d-axis inductance Ld, the q-axis inductance Lq and the magnetic flux φ of the permanent magnet are set. Is set and stored.

The switch 5 includes a control signal S1 output from the torque controller 6, control signals S2, S3, S4 output from the position / speed estimating means 7, a control signal S5 output from the motor constant calculating means 8, and a magnetic flux calculating means. 10 is a switch for selecting one of the control signals S6 output. When the torque of the permanent magnet type synchronous motor 1 is controlled, the control signal S1 is output to the power converter 4, and when the motor constant is unknown, the permanent magnet Are estimated to the power converter 4 in the order of the control signals S2, S3, and S4, and the d-axis inductance L
When the d and q-axis inductances Lq and the resistance components R are calculated, the control signal S5 is output to the power converter 4, and when the magnetic flux φ of the permanent magnet is calculated, the control signal S6 is converted to the power converter 4.
Output to

FIG. 2 is a detailed block diagram of the position / velocity estimating means 7 in FIG. 1. Reference numeral 15 denotes dq-axis determining means, which inputs a d-axis voltage vd and a q-axis voltage vq, A control signal S2 in which an AC current flows as the axis current id, and an AC current having a phase different from the d-axis current id by 90 degrees and the same amplitude flows as the q-axis current iq, and the magnitude of the amplitude of the d-axis voltage vd and q By comparing the magnitude of the amplitude of the shaft voltage vq,
If the amplitude of the d-axis voltage vd is larger, the signal Sθ1 for advancing or delaying the estimated direction θg of the permanent magnet by 90 degrees.
Is output.

Numeral 16 denotes a magnetic pole determining means, which is a d-axis current id.
And the d-axis voltage vd, the q-axis current iq does not flow, and d
The average value of the control signal S4 in which a large AC current flows so that magnetic saturation occurs in the axis current id and the d-axis voltage vd when the d-axis current id is positive is d when the d-axis current id is negative. A signal Sθ2 for advancing the estimated direction θg of the permanent magnet by 180 degrees when the average value of the shaft voltage vd is larger than the average value is output. 1
Reference numeral 7 denotes a position / velocity correcting means which controls the control signal S such that the q-axis current iq does not flow and the AC current flows to the d-axis current id.
3. Estimated rotational speed ωg of permanent magnet type synchronous motor 1
And the estimated direction θg of the permanent magnet is output. Less than,
The details will be described with reference to FIG.

In FIG. 3, reference numeral 18 denotes a differentiator, and a q-axis current i
Differentiate q. Reference numeral 19 denotes an inductance voltage drop calculator for calculating the product of the output of the differentiator 18 and the q-axis inductance Lq. Reference numeral 20 denotes a resistance voltage drop calculator, and q
The product of the shaft current iq and the armature resistance R is output. Reference numeral 21 denotes an adder. When estimating the direction of the permanent magnet before setting and storing the constant of each unit, the output of the adder 21 is clipped to 0 V (not shown) by any method, and the constant of each unit is set and stored. In this case, the clipping circuit does not operate, and in this case, the output of the voltage drop calculator for inductance 19 and the output of the voltage drop calculator for resistance 20 are added.

A subtracter 22 receives the output of the adder 21 and the q-axis voltage vq, and outputs a value obtained by subtracting the output of the adder 21 from the q-axis voltage vq. 23 is a differentiator for differentiating the output of the subtractor 22. Reference numeral 24 denotes a position error detecting means, which outputs a product a of the d-axis current id and the output dvq of the differentiator 23. Reference numeral 25 denotes a low-pass filter which removes a harmonic component of the output a of the position error detecting means 24 and removes the DC component af
Output only

Reference numeral 26 denotes a speed estimating means, which receives the output af of the low-pass filter 25 and outputs the rotational speed ωg of the permanent magnet type synchronous motor 1. 27 is a position estimating means, which is the output Sθ1 of the dq axis determining means 15 and the magnetic pole determining means 1
6 and the estimated rotation speed ωg, and outputs a control signal S3 and an estimated permanent magnet direction θg such that an AC current flows through the d-axis current id without flowing the q-axis current iq.

Hereinafter, the reason why the above problem can be solved by the present invention will be described. First, in order to explain the reason why the direction of the permanent magnet can be estimated according to claim 1, first,
The position / speed correcting means 17 will be described. FIG. 4 is a vector representing the relationship between the actual direction θgr of the permanent magnet φgr of the permanent magnet type synchronous motor 1 and the estimated direction θg of the permanent magnet φg.

[0019]

(Equation 1)

When there is a position error Δθ, as shown in Equation 2, if the AC current is passed as the d-axis current id without flowing the q-axis current iq,

[0021]

(Equation 2)

The dr-axis current component idr parallel to the actual direction θgr (hereinafter referred to as dr axis) of the permanent magnet φgr and the qr-axis current component iqr in the direction perpendicular to the dr axis (hereinafter referred to as qr axis) are represented by the following equation (3). Is represented by

[0023]

(Equation 3)

Here, Ih is the peak value of the AC current, ωh is the angular frequency of the AC current, and t is the time. The characteristic equation of the permanent magnet type synchronous motor 1 is expressed by the following equation.

[0025]

(Equation 4)

Where vdr is the dr-axis voltage and vqr is q
The r-axis voltage, p is a differential operator, and ωgr is the actual rotation speed of the permanent magnet synchronous motor 1. Equation (6) and (7)
By substituting into equations (4) and (5),

[0027]

(Equation 5)

## EQU1 ## From the equations (8) and (9), the q-axis voltage vq is given by the following equation.

[0029]

(Equation 6)

Since the output a of the position error detecting means 24 is the product of the d-axis current id and the differential value dvq of the q-axis voltage vq, from the equations (2) and (10),

[0031]

(Equation 7)

And passes through a low-pass filter 25 to
Removing the high frequency components of

[0033]

(Equation 8)

## EQU1 ## Since Lq> Ld, from equation (12), it can be seen that when −90 degrees <Δθ <90 degrees, the sign of the position error Δθ and the sign of af are opposite. In other words, the direction θg of the estimated permanent magnet φg is
When the vehicle is traveling in the direction θgr in the direction of r, af <0, and the speed estimating means 26 performs proportional-plus-integral amplification.
Since the estimated rotational speed ωg of the permanent magnet type synchronous motor 1 becomes small, the estimated advance in the direction θg of the permanent magnet is slowed, and the estimated direction θg coincides with the actual direction θgr of the permanent magnet. The same applies to the opposite case.

When the rotational speed of the permanent magnet synchronous motor 1 and the direction of the permanent magnet are estimated by the position / speed correcting means 17, an alternating current is passed as the d-axis current id. Then, an AC component also appears in the q-axis current iq due to interference between the d-axis and the q-axis. The AC component of the q-axis current iq appears also in the q-axis voltage vq. Therefore, in FIG. 3, the q-axis voltage vq is changed to ｛vq− ( R + p · Lq)
・ Iq｝ is substituted. When estimating the direction of the permanent magnet at a stage where the armature resistance R, the d-axis inductance Ld, and the q-axis inductance Lq are unknown, the subtractor 22 sets q
The shaft voltage vq is output as it is.

That is, from equation (12), af corresponding to the position error Δθ is obtained from the product of the differential value of the d-axis current id and the differential value of the q-axis voltage vq. Can be.

Next, the case where the position error Δθ is shifted by 90 degrees will be described. Position / speed correction means 1 described above
In the method of estimating the direction of the permanent magnet according to 7, when the initial position error Δθ is around ± 90 degrees, af becomes unstable and the direction θg of the permanent magnet cannot be estimated. However, according to the present invention, the correction can be performed by causing the dq-axis determination means 15 to flow the currents shown in Expressions (13) and (14) of Expression 9 on the d-axis and the q-axis. Hereinafter, this point will be described.

[0038]

(Equation 9)

Since the position error Δθ changes when the permanent magnet synchronous motor 1 rotates, the estimated direction θg of the permanent magnet cannot be corrected by the following method.
First, the fact that the motor does not rotate even when the currents of equations (13) and (14) are applied will be described. If there is a position error Δθ expressed by the equation (1), the dr-axis current idr and the qr-axis current iqr that actually flow are given by the equations (13) and (14).

[0040]

(Equation 10)

## EQU1 ## On the other hand, the torque type of the permanent magnet type synchronous motor 1 is as follows.

[0042]

[Equation 11]

## EQU4 ## By substituting equations (15) and (16) into equation (17), the torque generated by the permanent magnet synchronous motor 1 is expressed by the following equation.

[0044]

(Equation 12)

As shown in the equation (18), since the generated torque is only the AC component, it is 0 on average, and the permanent magnet type synchronous motor 1 does not rotate. Next, the position error Δθ
It will be described that the detection of whether or not the angle is shifted by 90 degrees can be performed by flowing the currents shown in Expressions (13) and (14) of Expression 9 on the d-axis and the q-axis. When the permanent magnet type synchronous motor is stopped, the actual dr-axis voltage vdr and qr-axis voltage vqr are calculated by using Equation (15) and Equation (16) as Equation (6).
By substituting into equation (7), equations (19) and (20)
The d-axis voltage vd and the q-axis voltage vq are expressed by (2
Expressions 1) and (22) are used.

[0046]

(Equation 13)

[0047]

[Equation 14]

Here,

[0049]

(Equation 15)

Is as follows. From the relationship of Ld <Lq, (23)
From the expressions and the expression (25), it can be seen that the magnitude Vd of the amplitude of the d-axis voltage vd becomes larger than the magnitude Vq of the amplitude of the q-axis voltage vq as the position error Δθ approaches ± 90 degrees. As described above, by flowing the currents represented by Expressions (13) and (14), the motor constants can be used without using the motor constants.
With the permanent magnet synchronous motor 1 stopped, the d-axis voltage v
By comparing the magnitude of the amplitude of d with the magnitude of the amplitude of the q-axis voltage vq, it is possible to easily determine whether the position error Δθ is ± 90 degrees.

However, the dq-axis determination means 15 can determine whether the position error Δθ is 90 degrees, but cannot estimate the position error Δθ based on the sign or the exact size of the position error Δθ. Therefore, if the magnitude of the d-axis voltage vd is larger than the magnitude of the q-axis voltage vq with the permanent magnet synchronous motor 1 stopped, the estimated direction θg of the permanent magnet is set to 9
The direction θg of the permanent magnet estimated by the above-described position / speed estimating means 17 and the magnetic pole determining means 16 described later is corrected by moving forward or backward by 0 degrees.

Next, the case where the position error Δθ is shifted by 180 degrees will be described. From equation (12), the position error Δθ
Is smaller than -90 degrees <Δθ <90 degrees, the position error Δθ is corrected in a decreasing direction. However, when the position error Δθ is ± 90 degrees or more, the sign of the position error Δθ and Since the code is the same, the position error Δθ is 180 degrees.

However, according to the present invention, the correction can be performed by flowing the currents shown in the equations (2) and (3) of the equation (2) on the d-axis and the q-axis (however, the AC current in the equation (2)) Is a value that is large enough to cause magnetic saturation). Hereinafter, this point will be described. Note that the dq axis determination means 1
5, the position error Δθ changes when the permanent magnet synchronous motor 1 rotates, so that the estimated permanent magnet direction θg cannot be corrected by the following method.
First, it will be described that the motor does not rotate even when the currents of the equations (3) and (3) are applied. The position error Δθ of the direction θg of the permanent magnet estimated by the position / speed correction means 7 is 0 or 1
Since it is 80 degrees, the dr-axis current idr and the qr-axis current iqr that actually flow are given by the equations (4) and (5).

[0054]

(Equation 16)

Is as follows. Since iqr = 0, the torque of the permanent magnet synchronous motor 1 shown in Expression (17) becomes 0, and the permanent magnet synchronous motor 1 does not rotate. Next, the position error Δ
The detection of whether or not θ is shifted by 180 degrees is based on Expression 2 (2).
The fact that it becomes possible by flowing the current shown in the equation (3) will be described.

When the direction of the permanent magnet is correctly estimated, the d-axis inductance Ld is determined as follows. If the d-axis current id is positive, the direction of the magnetic flux due to the d-axis current id is equal to the direction of the magnetic flux of the permanent magnet, and the d-axis inductance Ld Becomes smaller and d
If the axis current id is negative, the direction of the magnetic flux due to the d-axis current id and the direction of the magnetic flux of the permanent magnet become opposite, and a magnetic saturation phenomenon occurs in which the d-axis inductance Ld increases. Then, q
The axis current iq is not passed, but a large alternating current is applied to the d-axis current id so as to cause magnetic saturation, and the magnetic pole determination means 16 calculates the average value of d-axis voltage vd and d-axis current vd when the d-axis current id is positive. By comparing the d-axis voltage vd when the axis current id is negative, a position error Δθ of 180 degrees can be determined.

As described above, by applying the currents shown in the equations (2) and (3), even before the motor constants are used, the permanent magnet type synchronous motor 1 can be stopped even before the motor constants are used. By comparing the average value of the d-axis voltage vd when the d-axis current id is positive and the d-axis voltage vd when the d-axis current id is negative, the position error Δθ of 180 degrees can be easily determined. become.

Next, according to claim 1, when the position error Δθ is 0, the currents as expressed by the equations (13) and (14) are applied to the d-axis current id and the q-axis current iq, so that the motor constant In order to explain the reason why can be measured, the motor constant calculation means 8 will be described. It should be noted that when the permanent magnet type synchronous motor 1 rotates, the motor constant cannot be measured. However, the fact that the motor does not rotate when the currents of equations (13) and (14) flow is shown in equation (18) above. It is clear that no rotation occurs when Δθ is zero. Next, a description will be given of the fact that the motor constant can be measured by flowing the currents shown in Expressions (13) and (14) in the d-axis direction and the q-axis direction when the position error Δθ is 0. When the position error Δθ is 0 and the permanent magnet synchronous motor 1 is stopped, idr = id, iqr = iq, vdr = vd,
Since vqr = vq and ωgr = 0, Equation (6) and (7)
The equations are represented by equations (30) and (31), respectively.

[0059]

[Equation 17]

Therefore, it can be seen from the equation (30) that the d-axis inductance Ld and the resistance component Rd can be calculated from the magnitude and phase of the d-axis voltage vd and the magnitude and phase of the d-axis current id. It can be seen from the equation that the q-axis inductance Lq and the resistance component Rq can be calculated. As described above, when the position error Δθ is 0 and the permanent magnet type synchronous motor 1 is stopped, the currents represented by the equations (13) and (14) are passed to obtain the inductance Ld of the d-axis and the q-axis. And the armature resistance R can be calculated at the same time, making it possible to automatically measure and set the current without fixing the permanent magnet synchronous motor as in the prior art and measuring the current. .

Next, to explain the reason why the magnetic flux of the permanent magnet can be measured according to claim 2, the magnetic flux calculating means 10 will be described. It is assumed that the d-axis inductance Ld, the q-axis inductance Lq, and the armature resistance R are set and stored in the setting storage unit 9, and the direction θg and rotation speed ωg of the permanent magnet are estimated by the position / speed estimation unit 7. As shown in the following equation, an AC current flows through the d-axis current id, and a DC current flows through the q-axis current iq.

[0062]

(Equation 18)

When the equations (32) and (33) are substituted into the equation (17), the torque generated by the permanent magnet type synchronous motor 1 becomes the equation (34).

[0064]

[Equation 19]

Since the second term of the equation (34) is an AC component, it averages to zero. However, since the first term is a DC component, a constant torque appears in the permanent magnet synchronous motor 1 and the permanent magnet synchronous motor 1 1 rotates. Therefore, from equation (7),

[0066]

(Equation 20)

Thus, the dr-axis current idr, qr
If the axis current iqr, the qr-axis voltage vqr, the d-axis inductance Ld, the q-axis inductance Lq, the armature resistance R, the rotational speed ωg, and the direction θg of the permanent magnet can be calculated, the magnetic flux φ of the permanent magnet can be calculated. As described above, the d-axis inductance Ld, the q-axis inductance Lq, and the armature resistance R are set and stored in the setting storage unit 9, and the direction θg and the rotational speed ωg of the permanent magnet are estimated by the position / speed estimation unit 7. , (32) and (33), the magnetic flux φ of the permanent magnet can be calculated, and the measurement is automatically performed without using a position detector or a speed detector as in the conventional case. And it became possible to set.

[0068]

According to the present invention, it is possible to set the control device without using a device for measuring the motor constant of the permanent magnet synchronous motor, so that the control device can be adjusted easily and with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an embodiment of the present invention.

FIG. 3 is a block diagram illustrating an embodiment of the present invention.

FIG. 4 is a vector diagram illustrating the principle of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 permanent magnet type synchronous motor 2 voltage detector 3 current detector 4 power converter 5 switch 6 torque controller 7 position / speed estimation means 8 motor constant calculation means 9 setting storage means 10 magnetic flux calculation means 13 current component converter 14 voltage Component converter 15 dq-axis determination means 16 Magnetic pole determination means 17 Position / speed correction means 18 Differentiator 19 Inductance voltage drop calculator 20 Resistance voltage drop calculator 21 Adder 22 Subtractor 23 Differentiator 24 Position error detecting means 25 Low-pass filter 26 Speed estimating means 27 Position estimating means

Claims (3)

[Claims] 1. A d-axis current component parallel to an estimated permanent magnet direction (hereinafter referred to as d-axis) and a primary current flowing through a permanent magnet type synchronous motor and an axis perpendicular to the d-axis (hereinafter referred to as q-axis). In the method for controlling a synchronous motor that controls the q-axis current component separately in the q) -direction, an alternating current is passed as a d-axis current in a state where the permanent magnet type synchronous motor is stopped, and a d-axis current is d.
An alternating current having a phase difference of 90 degrees and an equal amplitude is applied to the axis current, and the amplitude of the d-axis voltage is compared with the amplitude of the q-axis voltage. If the amplitude of the d-axis voltage is larger than the amplitude of the q-axis voltage, it is estimated. Forward or backward the direction of the permanent magnet by 90 degrees, q
An AC current is passed as the d-axis current without passing the shaft current, and the estimated direction of the permanent magnet is corrected by the product of the differential value of the q-axis voltage and the d-axis current. When the average value of the d-axis voltage when the d-axis current is positive is larger than the average value of the d-axis voltage when the d-axis current is negative, the estimated permanent magnet direction is changed by 180. When the estimation of the direction of the permanent magnet is completed, an AC current is passed as a d-axis current, and an AC current having a 90-degree phase difference and an equal amplitude with respect to the d-axis current is passed to the q-axis. From the magnitude and phase of the current and the magnitude and phase of the d-axis voltage, the d-axis inductance Ld and the resistance component Rd of the permanent magnet synchronous motor
The synchronous motor is characterized in that the q-axis inductance Lq and the resistance component Rq of the permanent magnet synchronous motor are determined and stored from the magnitude and phase of the q-axis current and the magnitude and phase of the q-axis voltage. Control method. 2. The synchronous motor control method according to claim 1, wherein an average value of the resistance component Rd and the resistance component Rq is set and stored as an armature resistance R of the permanent magnet type synchronous motor. 3. An AC current is passed as a d-axis current, a DC current is passed as a q-axis current, and a permanent magnet type synchronous motor is rotated. And the rotational speed of the permanent magnet type synchronous motor are estimated, and the armature resistance R, the d-axis inductance Ld, the q-axis inductance Lq, the estimated permanent magnet direction, the estimated rotational speed, the d-axis current, q 2. The synchronous motor control method according to claim 1, wherein the shaft current and the q-axis voltage are inputted, and the magnetic flux of the permanent magnet is obtained and set and stored.