JP6590196B2 - Power converter - Google Patents

Description

  The present invention relates to a technique for stably controlling a permanent magnet type synchronous motor.

  When a permanent magnet synchronous motor (hereinafter also referred to as PMSM) is controlled by an inverter, the output voltage of the inverter becomes unstable when the current is small as in a light load, and vibration occurs in the current. Patent Document 1 discloses a technique for preventing current from becoming zero at light load in order to reduce current vibration at no load.

  FIG. 24 is a block diagram of a PMSM control device described in Patent Document 1. In FIG. In the figure, reference numerals 501 and 507 are coordinate conversion means, 502 is a reactive current (d-axis current) command calculation means, 503 is a torque current (q-axis current) command calculation means, and 504 is caused by the interaction between reactive current and torque current. Interference voltage compensation means for compensating the error, 505 is reactive current control calculation means, and 506 is torque current control calculation means.

In this prior art, the reactive current command calculation unit 502 sets the reactive current command value i _d ^* to a positive value if the torque current i _q output from the coordinate conversion unit 501 is equal to or less than a predetermined value, and the torque current i _{If q} exceeds a predetermined value, reactive current command value i _d ^* is set to zero. In this way, the reactive current is injected only when the torque current i _q is a small value close to zero, and the inverter output current is controlled so as not to become zero. Suppressed.

PMSM includes a surface magnet synchronous motor (hereinafter referred to as SPMSM) in which the rotor has no saliency and an embedded magnet synchronous motor (hereinafter referred to as IPMSM) in which the rotor has saliency.
The SPMSM can maximize the torque / current by controlling the d-axis current to zero, while the IPMSM can maximize the torque / current by controlling the d-axis current to a negative value according to the load. Can be. In addition, both SPMSM and IPMSM can control the terminal voltage by controlling the d-axis current to a negative value, and by using this, the terminal voltage is reduced to the maximum output of the power converter such as an inverter above the base speed. So-called flux-weakening control that improves the maximum speed by suppressing the above-mentioned has been put into practical use.

Japanese Patent No. 3678558 (Claim 3, paragraphs [0032] to [0034], FIG. 5, FIG. 6, etc.)

  However, in the prior art described in the above-mentioned Patent Document 1, when the q-axis current command value is larger than a predetermined value, the d-axis current is controlled to be zero. Therefore, when this is applied to IPMSM, torque / current Cannot be controlled to the maximum, and flux-weakening control cannot be realized.

  Therefore, the problem to be solved by the present invention is to improve the stability at the time of light load, maximize the torque / current at the time of heavy load, and increase the terminal voltage to the power in the control device for the permanent magnet type synchronous motor including the IPMSM. It is an object of the present invention to provide a control device that can control the voltage below the maximum voltage of the converter to improve the maximum speed.

In order to solve the above-mentioned problems, the invention according to claim 1 regards the current of a permanent magnet type synchronous motor driven by a power converter as a vector, and uses the current vector with respect to the rotor magnetic pole of the permanent magnet type synchronous motor. In the control device for the permanent magnet type synchronous motor, the power converter is controlled by being decomposed into a d-axis current in a parallel direction and a q-axis current in a direction orthogonal to the d-axis current,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a q-axis current command value;
Means for calculating a d-axis current compensation value from the q-axis current command value;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for controlling the power converter based on the second d-axis current command value and the q-axis current command value;
When the d-axis current compensation value is a value greater than or equal to zero and is a decreasing function of the absolute value of the q-axis current command value, and the absolute value of the speed of the permanent magnet synchronous motor is large, the first The d-axis current command value is limited by a negative upper limit value, and the second d-axis current command value is calculated .

  According to a second aspect of the present invention, in the control device for the permanent magnet type synchronous motor according to the first aspect, the d-axis current compensation value is a decreasing function of an absolute value of speed.

According to a third aspect of the present invention, in the control device for the permanent magnet type synchronous motor according to the first or second aspect, the d-axis current compensation value is used instead of the q-axis current command value. It is characterized by calculating.

According to a fourth aspect of the present invention, there is provided a permanent magnet synchronous motor control device according to any one of the first to third aspects, wherein the torque is calculated from the second d-axis current command value and the q-axis current command value. And a means for calculating a calculated value, and a means for calculating the first d-axis current command value and the q-axis current command value so that the torque calculated value coincides with the torque command value. To do.

In the invention according to claim 5, the current of the permanent magnet type synchronous motor driven by the power converter is regarded as a vector, and the current vector is d-axis current parallel to the rotor magnetic pole of the permanent magnet type synchronous motor. And a permanent magnet type synchronous motor control device that controls the power converter by breaking it into a q-axis current orthogonal to the d-axis current ,
The axis parallel to the current vector that maximizes the torque / current of the permanent magnet type synchronous motor is the qm axis, the axis perpendicular to the qm axis is the dm axis, the current in the qm axis direction is the qm axis current, and the dm axis direction is Define each current as dm-axis current,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a second q-axis current command value;
Means for calculating an angular difference between the d-axis and the dm-axis from the torque of a permanent magnet synchronous motor;
means for calculating a dm-axis current compensation value from the qm-axis current;
Means for calculating a d-axis current compensation value and a q-axis current compensation value from the dm-axis current compensation value and the angle difference;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for adding the first q-axis current command value and the q-axis current compensation value to calculate the second q-axis current command value ;
It is provided with.

The invention according to claim 6 is the control device for a permanent magnet type synchronous motor according to claim 5 , further comprising means for calculating the qm-axis current from the torque .

The invention according to claim 7 is the control device for the permanent magnet type synchronous motor according to claim 5 , further comprising means for calculating the qm-axis current from the d-axis current, the q-axis current, and the angular difference. It is characterized by that.

According to an eighth aspect of the present invention, in the controller for a permanent magnet synchronous motor according to any one of the fifth to seventh aspects, the dm-axis current compensation value is a value equal to or greater than zero, and the qm-axis current It is a decreasing function of the absolute value of .

The invention according to claim 9 regards the current of the permanent magnet type synchronous motor driven by the power converter as a vector, and the current vector is d-axis current parallel to the rotor magnetic pole of the permanent magnet type synchronous motor. And a permanent magnet type synchronous motor control device that controls the power converter by breaking it into a q-axis current orthogonal to the d-axis current ,
The axis parallel to the current vector that maximizes the torque / current of the permanent magnet type synchronous motor is the qm axis, the axis perpendicular to the qm axis is the dm axis, the current in the qm axis direction is the qm axis current, and the dm axis direction is Define each current as dm-axis current,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a second q-axis current command value;
Means for calculating an angular difference between the d-axis and the dm-axis from the torque;
Means for calculating a dm-axis current compensation value from the torque;
Means for calculating a d-axis current compensation value and a q-axis current compensation value from the dm-axis current compensation value and the angle difference;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for adding the first q-axis current command value and the q-axis current compensation value to calculate the second q-axis current command value;
It is provided with.

According to a tenth aspect of the present invention, in the control device for the permanent magnet type synchronous motor according to the ninth aspect, the dm-axis current compensation value is a value not less than zero and is a decreasing function of the absolute value of the torque. It is characterized by.

The invention according to claim 11 is the permanent magnet synchronous motor control device according to any one of claims 5 to 10, wherein the d-axis current compensation value is an absolute value of a speed of the permanent magnet synchronous motor . It is a decreasing function.

The invention according to claim 12 is the control device for the permanent magnet type synchronous motor according to any one of claims 5 to 11 , wherein the first value of the permanent magnet type synchronous motor is large when the absolute value of the speed of the permanent magnet type synchronous motor is large. The d-axis current command value is limited by a negative upper limit value, and the second d-axis current command value is calculated .

According to the present invention, it is possible to improve the stability of the PMSM when the load is light and to maximize the torque / current when the load is heavy. Furthermore, it is easy to control the terminal voltage of PMSM below the maximum voltage of a power converter such as an inverter, which can contribute to the improvement of the maximum speed.
In addition, if a dm-axis current that has a small influence on torque is flowed to avoid zero current, a torque control error can be reduced.

It is a control block diagram showing the overall structure of the implementation of the invention. It is a figure which shows the definition of a coordinate axis. It is a block diagram which shows the structure of the electric current command calculating part in FIG. It is a block diagram which shows the 1st Example of the zero current avoidance computing unit in 1st Embodiment . It is a figure which shows the relationship between the absolute value of q-axis current command value or qm-axis current command value, and d-axis current compensation value in 1st Embodiment or 3rd Embodiment. It is a figure which shows the relationship between an electric current and torque when IPMSM is controlled by 1st Embodiment or 3rd Embodiment. It is a block diagram showing a second embodiment of the zero current avoidance calculation unit in the first embodiment. It is a figure which shows the relationship between the absolute value of the speed in 1st Embodiment or 5th Embodiment, and the setting value of d-axis current compensation value or dm-axis current compensation value. It is a figure which shows the relationship between the absolute value of the speed in 1st Embodiment or 5th Embodiment, and the setting value of q-axis current command value or dm-axis current command value. It is a figure which shows the relationship between the absolute value of the speed in 1st Embodiment or 5th Embodiment, and the setting value of q-axis current command value or dm-axis current command value. It is a figure which shows the relationship between an electric current and torque when controlling IPMSM by 1st Embodiment or 5th Embodiment. It is a figure which shows the relationship between an electric current and torque when controlling IPMSM by 1st Embodiment or 5th Embodiment. Is a block diagram showing a third embodiment of the zero current avoidance calculation unit in the first embodiment. It is a figure which shows the relationship between the torque at the time of high speed when controlling IPMSM by 1st Embodiment, and an electric current. It is a block diagram which shows the structure of the electric current command calculating part in 2nd Embodiment . It is a figure which shows the definition of a coordinate axis. It is a block diagram which shows the structure of the current command calculating part in 3rd Embodiment. It is a block diagram which shows the structure of the zero current avoidance calculator in 3rd Embodiment. It is a block diagram which shows the structure of the zero current avoidance computing unit in 4th Embodiment. It is a block diagram which shows the structure of the zero current avoidance calculator in 5th Embodiment. It is a figure which shows the relationship between the torque and electric current at the time of high speed when controlling IPMSM by 6th Embodiment. It is a block diagram which shows the structure of the zero current avoidance computing unit in 7th Embodiment. It is a figure which shows the relationship between the absolute value of the torque command value in 7th Embodiment, and the setting value of a dm-axis current compensation value. It is a block diagram which shows a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, FIG. 1 is a control block diagram showing the overall structure of the implementation of the invention, for operating a PMSM without magnetic pole position detector, but when applied to a so-called sensorless control.
PMSM can realize high-performance torque control and speed control by controlling current and voltage on the d and q axes which are orthogonal rotation coordinate axes synchronized with the rotor. Here, for the d and q axes, the N pole direction of the magnetic poles of the rotor is defined as the d axis, and the direction advanced by 90 ° from the d axis is defined as the q axis. However, in the sensorless control, the positions of the d and q axes cannot be directly detected. Therefore, the control calculation is performed by defining the γ and δ axes, which are the estimated axes of the d and q axes, in the control device.

また、ｄ，ｑ軸の角速度をω_ｒ（回転子速度）と定義し、γ,δ軸の角速度（速度推定値）をω_１と定義する。 FIG. 2 is a diagram illustrating the definition of coordinate axes.
As shown in FIG. 2, the angle difference between the γ-axis angle (position estimation value) θ ₁ with respect to the PMSM u-phase winding as a reference and the d-axis angle (magnetic pole position) θ _r with respect to the u-phase winding as a reference. (Position estimation error) θ _err is defined by Equation 1.

Further, the angular velocity of the d and q axes is defined as ω _r (rotor speed), and the angular velocity (speed estimated value) of the γ and δ axes is defined as ω ₁ .

Next, returning to FIG. 1, the configuration and operation of the first embodiment will be described.
First, PMSM speed control, current control, and voltage control will be described.
The subtractor 16 calculates a deviation between the speed command value ω _r ^* and the speed estimated value ω _1, and the speed controller 17 calculates the torque command value τ ^* so that the deviation becomes zero. The current command calculation unit 18 calculates a d-axis current command value i _d ^* and a q-axis current command value i _q ^* for generating a desired torque from the torque command value τ ^* . These d-axis current command value i _d ^* and q-axis current command value i _q ^* are controlled so that the current flowing through PMSM 80 does not become zero even when torque command value τ ^* is small.

The phase current detection values i _u and i _w detected by the u-phase current detector 11 u and the w-phase current detector 11 w on the output side of the power converter 70 are detected by the coordinate converter 14 using the estimated position value θ _1. Coordinates are converted to γ and δ axis current detection values i _γ and i _δ .
The d-axis current regulator 20a calculates the γ-axis voltage command value v _γ ^* so that the deviation between the d-axis current command value i _d ^* calculated by the subtracter 19a and the γ-axis current detection value i _γ becomes zero. . The q-axis current regulator 20b calculates the δ-axis voltage command value v _δ ^* so that the deviation between the q-axis current command value i _q ^* calculated by the subtractor 19b and the δ-axis current detection value i _δ becomes zero. .
The coordinate converter 15 performs coordinate conversion of the γ-axis voltage command value v _γ ^* and the δ-axis voltage command value v _δ ^* based on the position estimated value θ ₁ , and phase voltage command values v _u ^* , v _v ^* , v _w. ^* Ask for.

The rectifier circuit 60 rectifies the three-phase AC voltage of the three-phase AC power source 50 to convert it into a DC voltage, and supplies this DC voltage to a power converter 70 such as an inverter.
The PWM circuit 13 generates a gate signal for controlling the output voltage of the power converter 70 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* . The power converter 70 controls the internal semiconductor switching element based on the gate signal, thereby controlling the terminal voltage of the PMSM 80 to the phase voltage command values v _u ^* , v _v ^* , v _w ^* .
With the above control, the speed of the PMSM 80 can be controlled in accordance with the speed command value ω _r ^* .

Next, the magnetic pole position / velocity estimation technique of the PMSM 80 will be described.
The expansion induced voltage calculator 31 in FIG. 1 calculates the expansion induced voltage using Equation 2.

In Equation 2, the γ-axis voltage command value v _γ ^* and the δ-axis voltage command value v _δ ^* are used as the γ-axis voltage v _γ and the δ-axis voltage v _δ , respectively.
In addition, the calculation of Equation 2 is performed by measuring the phase voltage or line voltage of the PMSM 80 by a voltage detection circuit (not shown), and calculating the γ-axis voltage v _γ and δ-axis calculated from these measured values and the estimated position value θ _1. The voltage v _δ may be used.

Next, a method of calculating the magnetic pole position / velocity using the γ, δ-axis extended induced voltages e _exγestt , e _exδest calculated by the extended induced voltage calculator 31 will be described.
The angle difference calculator 32 calculates a position estimation error θ _errest from the γ and δ-axis expansion induced voltages e _exγestt and e _exδest by Equation 3.

なお、数式４において、Ｋ_{Ｐωｅｓｔ}は比例ゲイン、Ｔ_{Ｉωｅｓｔ}は積分時間である。
積分器３４は、速度推定値ω_１を積分して位置推定値θ_１を演算する。
これらの演算により、位置推定誤差θ_ｅｒｒが零になるように位置推定値θ_１と速度推定値ω_１とが演算され、これらの値を真値に収束させることができる。 The speed estimator 33 obtains a speed estimated value ω ₁ by _performing a proportional / integral calculation on the position estimation error θ _{errest according} to Equation 4.

In Equation 4, K _Pωest is a proportional gain, and T _Iωest is an integration time.
The integrator 34 integrates the speed estimated value ω ₁ to calculate the position estimated value θ ₁ .
By these calculations, the position estimated value θ ₁ and the speed estimated value ω ₁ are calculated so that the position estimation error θ _err becomes zero, and these values can be converged to true values.

Next, the current command calculation unit 18 will be described.
FIG. 3 is a block diagram showing a configuration of the current command calculation unit 18. In FIG. 3, the torque control unit 181 outputs a desired torque from the torque command value τ ^* and the speed ω _r (sets the speed estimated value ω ₁ ), and sets the terminal voltage to the maximum value of the power converter 70. A d-axis current command value (first d-axis current command value) i _dAδR ^* and a q-axis current command value i _qAδR ^* for _{lowering the} output voltage are calculated. These d-axis current command value i _dAδR ^* and q-axis current command value i _qAδR ^* are calculated so that the torque / current becomes maximum at a low speed when the terminal voltage is equal to or lower than the maximum output voltage of the power converter 70.
The zero current avoidance computing unit 182 uses the d-axis current command value (the first current command value i _dAδR ^* , the q-axis current command value i _qAδR ^* , and the speed ω _r so that the current of the PMSM 80 does not become zero. 2 d-axis current command value) i _d ^* and q-axis current command value i _q ^* .

Next, the zero current avoidance calculator 182 in FIG. 3 will be described.
FIG. 4 is a block diagram showing the configuration of the zero current avoidance calculator 182 as the first embodiment . The d-axis current compensator 182a calculates the d-axis current compensation value i _dcomp from the q-axis current command value i _qAδR ^* . The adder 182b adds the d-axis current command value i _dAδR ^* and the d-axis current compensation value i _dcomp to calculate the d-axis current command value i _d ^* . The q-axis current command value i _q ^* is controlled to the q-axis current command value i _qAδR ^* .

FIG. 5 shows the relationship between the q-axis current command value i _qAδR ^* and the d-axis current compensation value i _dcomp (note that values in parentheses on the horizontal and vertical axes in FIGS. 5 and 6 will be described later. )
As shown in FIG. 5, the d-axis current compensation value i _dcomp is a positive value that is a decreasing function of the absolute value of the q-axis current command value i _qAδR ^* , and the d-axis current compensation value i _dcomp is a constant maximum value i. the q-axis current command value _{i qAδR} ^* of the absolute value when decreases from _dcompM and _{i Qth1,} a q-axis current command value _{i qAδR} ^* of the absolute value _{i Qth2} when d-axis current compensation value _{i DCOMP} becomes zero To do.

6, this first embodiment is a view showing the relationship between the current and torque upon controlling the IPMSM is a kind of PMSM.
When the IPMSM is controlled so that the torque / current is maximized, the relationship between the torque and the current is as shown by the broken line in FIG. When no load is applied, both the d-axis current i _d and the q-axis current i _q are zero, the q-axis current i _q increases in the positive direction as the torque increases, and the d-axis current i _d increases in the negative direction.
On the other hand, applying the first embodiment, d-axis current i _d at light loads is controlled in the forward direction than the torque / current maximum condition, the relationship between the torque and the current is shown by a solid line. As a result, stability at light loads can be improved, and torque / current can be controlled to the maximum at heavy loads.
In addition, in the calculation of the d-axis current compensation value i _dcomp by the zero current avoidance calculator 182 in FIG. 3, the δ-axis current detection value i _δ (substantially equal to the q-axis current) is used instead of the q-axis current command value i _qAδR ^*. May be used.

Next, FIG. 7 is a block diagram showing a zero-current avoidance calculation unit 182A of the configuration of a second embodiment of the zero current avoidance calculation unit 182 in FIG. 3.

In FIG. 7, the difference from FIG. 4 is only the calculation contents of the d-axis current compensator 182a, and the rest is the same as FIG. The d-axis current compensator 182a calculates the d-axis current compensation value i _dcomp based on the q-axis current command value i _qAδR ^* and the speed ω _r . The d-axis current compensation value i _dcomp is a decreasing function of the absolute value of the q-axis current command value i _qAδR ^* , as in FIG. 5 described above.

In addition, in the second embodiment, the d-axis current compensation value _{i DCOMP} a decreasing function of the absolute value of the velocity omega _r.
Specifically, the set values i _dcompM , i _qth1 , i _qth2 in the compensation function in FIG. 5 are reduced functions of the absolute value of the speed ω _r as shown in FIGS. the horizontal axis in 12, brackets write the value on the vertical axis, you later).
FIG. 8 is a diagram showing a change in the set value i _dcompM , where i _dcompML is a set value corresponding to ω _rL and i _dcompMH is a set value corresponding to ω _rH . FIG. 9 is a diagram showing changes in the set value i _qth1 , where i _qth1L is a set value corresponding to ω _rL and i _qth1H is a set value corresponding to ω _rH . Further, FIG. 10 is a diagram showing changes in the set value i _qth2 , where i _qth2L is a set value corresponding to ω _rL and i _qth2H is a set value corresponding to ω _rH .

11, FIG. 12 shows the relationship between the current and torque upon controlling the IPMSM the second embodiment, FIG. 11 is the low speed _{(| ω r | <ω rL} ), 12 during high-speed ( | ω _r | ≧ ω _rH ). In the second embodiment, at the time of light load, the more the low speed shown in FIG. 11, is largely controlled by the forward direction than the maximum condition of the d-axis current i _d and the torque / current as indicated by a solid line.

For example, in Japanese Patent Nos. 2858692 and 397508, a force that restrains the d-axis to the γ-axis is generated by causing a current to flow in the positive direction of the γ-axis that is the estimated axis of the d-axis during sensorless control. A technique for improving the stability at low speed is disclosed. In the second embodiment of the present invention, in addition to the effects of the first embodiment, the low speed can improve stability of the sensorless control by controlling a large d-axis current in the forward direction, high-speed at the time of the d-axis current The amount of compensation can be reduced to maximize torque / current.

Next, a third embodiment of the zero current avoidance calculator 182 in FIG. 3 will be described .
In the third embodiment, switching the d-axis current command value i _d ^* of the calculation method according to the speed omega _r. That is, low speed is used zero current avoidance calculation unit 182A shown in FIG. 7, the method for calculating the d-axis current compensation value _{i DCOMP} the same as the second embodiment. On the other hand, at high speed, a zero current avoidance calculator 182B is configured as shown in FIG. In FIG. 13, the d-axis current command value i _d ^* limits the upper limit value of the d-axis current command value i _dAδR ^* to the d-axis current upper limit value i _dlim by the limiter _182c . Here, the d-axis current upper limit value i _dlimp is a negative value.

14, when the control IPMSM the third embodiment, and shows the relationship between the torque and current at high speeds.
In a third embodiment, at the time of light load is as current flows by the d-axis current i _d is controlled to a negative value d-axis current upper limit value i _Dlimp, maximum condition of heavy load torque / current To be controlled. Compensation of the d-axis current command value i _dAδR ^* for avoiding zero current is the minimum necessary, and since the d-axis current is compensated in the negative direction, the terminal voltage does not increase.
From the above, according to the third embodiment, in addition to the effects of the second embodiment, it the terminal voltage is easy to below the maximum output voltage of the power converter 70, the improvement of the maximum speed is also possible is there.

[ Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, the current command calculation unit 18 in the first embodiment is replaced with another configuration.
FIG. 15 is a block diagram illustrating a configuration of a current command calculation unit 18A in the second embodiment.

In FIG. 15, the magnetic flux command calculator 121 calculates a magnetic flux command value Ψ _a0 ^* from the torque command value τ ^* . The load angle calculator 131 calculates the load angle command value δ ₀ ^* from the torque command value τ ^* . Here, the magnetic flux command value Ψ _a0 ^* and the load angle command value Ψ _a0 ^* are calculated so that the torque / current becomes maximum with respect to the torque command value τ ^* . Since it is difficult to perform these calculations online, a table of magnetic flux and load angle at which the torque / current is maximized is prepared, and using these tables, the magnetic flux command value Ψ _a0 ^* and the load angle command are prepared. The value Ψ _a0 ^* may be obtained.

出力制限器１２３により、磁束指令値Ψ_ａ０ ^＊の上限値を磁束制限値Ψ_ａｌｉｍにて制限することにより、磁束指令値Ψ_ａ ^＊を演算する。これにより、ＰＭＳＭ８０の端子電圧を電力変換器７０の最大出力電圧以下に制御するような磁束指令値を演算することができる。 The magnetic flux limit value calculator 122 calculates the magnetic flux limit value ψ _alim by Equation 5.

The output limiter 123 calculates the magnetic flux command value ψ _a ^* by limiting the upper limit value of the magnetic flux command value ψ _a0 ^* with the magnetic flux limit value ψ _alim . Thereby, a magnetic flux command value that controls the terminal voltage of PMSM 80 to be equal to or lower than the maximum output voltage of power converter 70 can be calculated.

The load angle adjuster 133 is configured by a proportional-integral adjuster, and calculates the load angle compensation value δ _comp so that the deviation between the torque command value τ ^* obtained by the subtractor 132 and the torque calculation value τ _calc becomes zero. To do. The adder 134 adds the load angle command value δ ₀ ^* and the load angle compensation value δ _comp to calculate the load angle command value δ ^* .

The coordinate converter 141 calculates the d and q-axis magnetic flux command values ψ _d ^* and ψ _q ^* from Equation 6 using the magnetic flux command value ψ _a ^* and the load angle command value δ ^* .

The current command calculator 142 calculates d and q-axis current command values i _dAδR ^* and i _qAδR ^* from the d and q-axis magnetic flux command values Ψ _d ^* and Ψ _q ^* using Equation 7.

The zero current avoidance computing unit 182A uses the d, q axis current command values i _dAδR ^* , i _qAδR ^* , and the speed ω _r so that the PMSM 80 current does not become zero, d axis current command values i _d ^* , The q-axis current command value i _q ^* is calculated. Here, the configuration of the zero current avoidance calculator 182A is the same as that in FIG.
The torque calculator 143 in FIG. 15 obtains the torque calculation value τ _calc from the d-axis current command value i _d ^* and the q-axis current command value i _q ^* using Equation 8.

With the above calculation, the d-axis current command value i _d ^* and the q-axis current command value i _q ^* are calculated so that the torque calculation value τ _calc matches the torque command value τ ^*. Torque control error due to compensation of the d-axis current command value i _dAδR ^* at.

[ Third Embodiment]
Next, a third embodiment of the present invention will be described.
In the third embodiment, the control coordinate axes of the control device include a dm, qm axis comprising a current vector maximizing the torque / current of the PMSM 80 and a qm axis parallel to the qm axis, and a dm axis orthogonal to the qm axis. In the zero current avoidance calculator in the current command calculation unit, the d-axis current command value i _d ^* and the q-axis current command value i _q ^* are calculated using the current components on the dm and qm axes. Is.
FIG. 16 is a diagram showing the definition of coordinate axes including the dm and qm axes, and the angle difference between the dm axis and the d axis is defined as δ _m .

Since the configuration of the entire control apparatus to which the third embodiment is applied is the same as that of FIG. 1, the description thereof is omitted, and the configuration of the current command calculation unit 18 will be described with reference to FIG.
FIG. 17 is a block diagram showing the configuration of the current command calculation unit 18B in the third embodiment. In FIG. 17, the torque control unit 181 outputs a desired torque from the torque command value τ ^* and the speed ω _r (sets the speed estimated value ω ₁ ), and uses the terminal voltage as the maximum output voltage of the power converter 70. A d-axis current command value (first d-axis current command value) i _dAδR ^* and a q-axis current command value (first q-axis current command value) i _qAδR ^* are calculated for the following. The d-axis current command value i _dAδR ^* and the q-axis current command value i _qAδR ^* are calculated so that the torque / current becomes maximum at a low speed when the terminal voltage is equal to or lower than the maximum output voltage of the power converter 70.
The zero current avoidance computing unit 182C uses the d axis current command value i _dAδR ^* , the q axis current command value i _qAδR ^* , the torque command value τ ^* , and the speed ω _r to prevent the PMSM 80 current from becoming zero. The command value (second d-axis current command value) i _d ^* and the q-axis current command value (second q-axis current command value) i _q ^* are calculated.

更に、加算器１８２ｇは、ｄ軸電流指令値ｉ_ｄＡδＲ ^＊とｄ軸電流補償値ｉ_{ｄｃｏｍｐ}とを加算してｄ軸電流指令値ｉ_ｄ ^＊を演算し、加算器１８２ｈは、ｑ軸電流指令値ｉ_ｑＡδＲ ^＊とｑ軸電流補償値ｉ_{ｑｃｏｍｐ}とを加算してｑ軸電流指令値ｉ_ｑ ^＊を演算する。 FIG. 18 is a block diagram showing the configuration of the zero current avoidance calculator 182C.
Torque / current maximum condition calculator 182d includes, qm-axis current command value _{i QmMTPA} when controlled from the torque command value tau ^* to the torque / current maximum condition ^*, the angular difference of the sine sin [delta _m between the d-axis and the dm-axis and calculating the cosine cos [delta] _m. These operations are performed using a table.
dm-axis current compensation value calculator 182e calculates the dm-axis current compensation value _{i Dmcomp} the qm-axis current command value _{i qmMTPA} ^*. The coordinate converter 182f calculates the d-axis current compensation value i _dcomp and the q-axis current compensation value i _qmcomp from Equation 9 using the dm-axis current compensation value i _dmcomp and sin δ _m and cos δ _m .

Furthermore, the adder 182g calculates the d-axis current command value i _d ^* by adding the d-axis current command value i _dAδR ^* and the d-axis current compensation value i _dcomp , and the adder _182h calculates the q-axis current command value. The q-axis current command value i _q ^* is calculated by adding i _qAδR ^* and the q-axis current compensation value i _qcomp .

In the third embodiment, the relationship between the qm-axis current command value i _qmMTPA ^* that is the input of the dm-axis current compensation value calculator 182e and the dm-axis current compensation value i _dmcomp that is the output is as shown in FIG. is there. That is, according to the absolute value of the qm-axis current command value _{i qmMTPA} ^*, calculates the dm-axis current compensation value _{i Dmcomp} as decreasing function of the qm-axis current command value _{i qmMTPA} ^*.

Further, the relationship between torque and current when the IPMSM is controlled according to the third embodiment is as shown in FIG. That is, when the IPMSM is controlled so as to maximize the torque / current, the relationship between the torque and the current is as shown by the broken line in FIG. When no load is applied, both the d-axis current i _d and the q-axis current i _q are zero, the q-axis current i _q increases in the positive direction as the torque increases, and the d-axis current i _d increases in the negative direction.

On the other hand, according to the third embodiment, the d-axis current _id is controlled to be more positive than the maximum torque / current condition when the load is light, and the relationship between torque and current is as shown by the solid line in FIG. . As a result, the stability can be improved at light loads, and the torque / current can be controlled to the maximum at heavy loads. Furthermore, since current flows in the dm-axis direction orthogonal to the qm-axis, which is the torque increasing direction, in order to avoid zero current, there is a feature that a torque control error hardly occurs.

[ Fourth Embodiment]
In the fourth embodiment, the zero current avoidance calculator 182C in the third embodiment is replaced with another configuration. FIG. 19 is a block diagram showing the configuration of the zero current avoidance calculator 182D in the fourth embodiment.
The difference between FIG 1 8 is only computations in the qm-axis current command value _{i qmMTPA} ^*, other is the same as FIG. 18. In FIG. 19, the coordinate converter 182i calculates a qm-axis current command value i _qmMTPA ^* from the d-axis current command value i _d ^* , the q-axis current command value i _q ^* , sin δ _m , and cos δ _m using Equation ₁₀ .

Thereby, even when the torque / current is not controlled to the maximum, the qm-axis current command value i _qmMTPA ^* can be accurately calculated.
The qm-axis current command value i _qmMTPA ^* is obtained by _replacing the d-axis current command value i _d ^* and the q-axis current command value i _q ^* with the d-axis current command value i _dAδR ^* and the q-axis current command value i _qAδR ^* . Or may be calculated using the γ-axis current detection value i _γ and the δ-axis current detection value i _δ .

[ Fifth Embodiment]
In the fifth embodiment, the zero current avoidance calculator 182C in the third embodiment is replaced with another configuration. FIG. 20 is a block diagram showing the configuration of the zero current avoidance calculator 182E in the fifth embodiment.
The difference between FIG 1 8 is only computations in the dm-axis current compensation value calculator 182e, other than is the same as FIG. 18.

dm-axis current compensation value calculator 182e calculates the dm-axis current compensation value _{i Dmcomp} the qm-axis current command value _{i qmMTPA} ^* and speed omega _r. Similarly to the third embodiment, the dm-axis current compensation value i _dmcomp is a positive value as shown in FIG. 5 and is a decreasing function of the absolute value of the qm-axis current command value i _qmMTPA ^* . Furthermore, in the fifth embodiment, the dm-axis current compensation value i _dmcomp is a decreasing function of the absolute value of the speed ω _r . Specifically, the set values i _dmcompM , i _qmth1 , and i _qmth2 in the compensation function in FIG. 5 are _assumed to be functions of decreasing the absolute value of the speed ω _r as shown in FIGS. 8, 9, and 10, respectively.

The relationship between torque and current when the IPMSM is controlled according to the fifth embodiment is as shown in FIGS. At light loads, the low speed shown in FIG. _{11 (| ω r | <ω} rL) about, than the maximum condition of the d-axis current i _d and the torque / current as indicated by a solid line is larger controlled by the positive direction of the sensorless control with stability is improved, high speed during the _{(| | ω r ≧ ω rH} ), it is possible to maximize the torque / current by reducing the compensation amount of the d-axis current i _d.

[ Sixth Embodiment]
In the sixth embodiment, the zero current avoidance calculator 182C in the third embodiment is replaced with another configuration.
In the sixth embodiment, the calculation method of the d-axis current command value i _d ^* is switched according to the speed ω _r . First, at low speed, the zero current avoidance calculator 182E shown in FIG. 20 is used, and the calculation method of the dm-axis current compensation value i _dmcomp is the same as that of the fifth embodiment.
On the other hand, at the time of high speed, the zero current avoidance calculator 182B shown in FIG. 13 is used. The d-axis current command value i _d ^* limits the upper limit value of the d-axis current command value i _dAδR ^* to the d-axis current upper limit value i _dlim by the limiter _182c . Here, the d-axis current upper limit value i _dlimp is a negative value.

FIG. 21 shows the relationship between torque and current at high speed when the IPMSM is controlled according to the sixth embodiment.
In the sixth embodiment, at the time of light load is as current flows by the d-axis current i _d is controlled to a negative value d-axis current upper limit value i _Dlimp, maximum condition of heavy load torque / current To be controlled. Compensation of the d-axis current command value i _dAδR ^* for avoiding zero current is the minimum necessary, and since the d-axis current is compensated in the negative direction, the terminal voltage does not increase.
From the above, according to the eighth embodiment, in addition to the effects of the seventh embodiment, it is easy to make the terminal voltage equal to or lower than the maximum output voltage of the power converter 70, and the maximum speed can be improved. is there.

[ Seventh Embodiment]
In the seventh embodiment, the zero current avoidance calculator 182C in the third embodiment is replaced with another configuration.
FIG. 22 is a block diagram of the zero current avoidance calculator 182F in the seventh embodiment. The difference between FIG 1 8 is only computations in the dm-axis current compensation value calculator 182e, other than is the same as FIG. 18.

Torque / current maximum condition calculator 182d in FIG. 22 calculates the sin [delta _m, cos [delta] _m from the torque command value tau ^*. The dm-axis current compensation value calculator 182e calculates a dm-axis current compensation value i _dmcomp from the torque command value τ ^* .
FIG. 23 is a diagram illustrating a relationship between a torque command value τ ^* that is an input of the dm-axis current compensation value calculator 182e and a dm-axis current compensation value i _dmcomp that is an output. The dm-axis current compensation value _{i Dmcomp} computed as a decreasing function of the torque command value tau ^* in accordance with the absolute value of the torque command value tau ^*. In FIG. 23, τ _th1 is the absolute value of the torque command value τ ^* when the dm-axis current compensation value i _dmcomp decreases from a certain maximum value i _dmcompM , and τ _th2 is the dm-axis current compensation value i _dmcomp is This is the absolute value of the torque command value τ ^* when it becomes zero.
As a result, the dm-axis current compensation value i _dmcomp can be easily calculated. The dm-axis current compensation value i _dmcomp may be calculated using a torque calculation value instead of the torque command value τ ^* .

[ Eighth Embodiment]
Although not shown, the eighth embodiment is obtained by replacing the zero current avoidance calculator 182A in the current command calculator 18A shown in FIG. 15 with a zero current avoidance calculator 182E of FIG.
According to the eighth embodiment, d, q-axis current command value i d *, i q * current command value as computed torque calculation value tau calc matches the torque command value tau * from i d *, i Since q * is calculated, a torque control error due to compensation of the d-axis current command value i dAδR * in the zero current avoidance calculator 182E can be suppressed.

  The control device according to the present invention is applicable not only to the sensorless control described as the embodiment but also to a system including a magnetic pole position detector, a speed detector, and the like.

11u: u-phase current detector 11w: w-phase current detector 13: PWM circuit 14, 15: coordinate converters 16, 19a, 19b: subtractor 17: speed regulators 18, 18A, 18B: current command calculation unit 20a: d-axis current regulator 20b: q-axis current regulator 31: expansion induced voltage calculator 32: angle difference calculator 33: speed estimator 34: integrator 50: three-phase AC power supply 60: rectifier circuit 70: power converter ( Inverter)
80: Permanent magnet synchronous motor (PMSM)
121: Magnetic flux command calculator 122: Magnetic flux limit value calculator 123: Output limiter 131: Load angle calculator 132: Subtractor 133: Load angle controller 134: Adder 141: Coordinate converter 142: Current command calculator 143 : Torque calculator 181: Torque controller 182, 182 A, 182 B, 182 C, 182 D, 182 E, 182 F: Zero current avoidance calculator 182 a: d-axis current compensator 182 b, 182 g, 182 h: adder 182 c: limiter 182 d: torque / Current maximum condition calculator 182e: dm-axis current compensation value calculator 182f, 182i: coordinate converter

Claims (12)

A current of a permanent magnet type synchronous motor driven by a power converter is regarded as a vector, and the current vector is calculated with respect to a d-axis current parallel to the rotor magnetic pole of the permanent magnet type synchronous motor and the d-axis current. In the control device for a permanent magnet synchronous motor, which is decomposed into q-axis current in the orthogonal direction to control the power converter,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a q-axis current command value;
Means for calculating a d-axis current compensation value from the q-axis current command value;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for controlling the power converter based on the second d-axis current command value and the q-axis current command value;
With
When the d-axis current compensation value is a value greater than or equal to zero and is a decreasing function of the absolute value of the q-axis current command value, and the absolute value of the speed of the permanent magnet synchronous motor is large, the first A control device for a permanent magnet type synchronous motor, wherein the second d-axis current command value is calculated by limiting a d-axis current command value with a negative upper limit value . In the control device for the permanent magnet type synchronous motor according to claim 1,
The control apparatus for a permanent magnet type synchronous motor, wherein the d-axis current compensation value is a decreasing function of an absolute value of speed. In the control device for a permanent magnet type synchronous motor according to claim 1 or 2,
A control apparatus for a permanent magnet synchronous motor, wherein the d-axis current compensation value is calculated using a q-axis current detection value instead of the q-axis current command value . In the control apparatus for the permanent magnet type synchronous motor according to any one of claims 1 to 3,
Means for obtaining a torque calculation value from the second d-axis current command value and the q-axis current command value;
Means for calculating the first d-axis current command value and the q-axis current command value so that the torque calculation value matches the torque command value;
Controller for a permanent magnet type synchronous motor characterized by comprising a. A current of a permanent magnet type synchronous motor driven by a power converter is regarded as a vector, and the current vector is calculated with respect to a d-axis current parallel to the rotor magnetic pole of the permanent magnet type synchronous motor and the d-axis current. In the control device for a permanent magnet synchronous motor, which is decomposed into q-axis current in the orthogonal direction to control the power converter ,
The axis parallel to the current vector that maximizes the torque / current of the permanent magnet type synchronous motor is the qm axis, the axis perpendicular to the qm axis is the dm axis, the current in the qm axis direction is the qm axis current, and the dm axis direction is Define each current as dm-axis current,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a second q-axis current command value;
Means for calculating an angular difference between the d-axis and the dm-axis from the torque of a permanent magnet synchronous motor;
means for calculating a dm-axis current compensation value from the qm-axis current;
Means for calculating a d-axis current compensation value and a q-axis current compensation value from the dm-axis current compensation value and the angle difference;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for adding the first q-axis current command value and the q-axis current compensation value to calculate the second q-axis current command value ;
A control device for a permanent magnet type synchronous motor. In the control device for the permanent magnet type synchronous motor according to claim 5 ,
A control device for a permanent magnet synchronous motor, comprising means for calculating the qm-axis current from the torque . In the control device for the permanent magnet type synchronous motor according to claim 5 ,
A control device for a permanent magnet type synchronous motor , comprising means for calculating the qm-axis current from the d-axis current, the q-axis current, and the angular difference . In the control device for a permanent magnet type synchronous motor according to any one of claims 5 to 7 ,
The controller for a permanent magnet type synchronous motor, wherein the dm-axis current compensation value is a value equal to or greater than zero and is a decreasing function of the absolute value of the qm-axis current . A current of a permanent magnet type synchronous motor driven by a power converter is regarded as a vector, and the current vector is calculated with respect to a d-axis current parallel to the rotor magnetic pole of the permanent magnet type synchronous motor and the d-axis current. In the control device for a permanent magnet synchronous motor, which is decomposed into q-axis current in the orthogonal direction to control the power converter ,
The axis parallel to the current vector that maximizes the torque / current of the permanent magnet type synchronous motor is the qm axis, the axis perpendicular to the qm axis is the dm axis, the current in the qm axis direction is the qm axis current, and the dm axis direction is Define each current as dm-axis current,
Means for controlling the d-axis current to a second d-axis current command value;
Means for controlling the q-axis current to a second q-axis current command value;
Means for calculating an angular difference between the d-axis and the dm-axis from the torque;
Means for calculating a dm-axis current compensation value from the torque;
Means for calculating a d-axis current compensation value and a q-axis current compensation value from the dm-axis current compensation value and the angle difference;
Means for adding the first d-axis current command value and the d-axis current compensation value to calculate the second d-axis current command value;
Means for adding the first q-axis current command value and the q-axis current compensation value to calculate the second q-axis current command value;
Controller for a permanent magnet type synchronous motor characterized by comprising a. In the control device for the permanent magnet type synchronous motor according to claim 9 ,
The controller for a permanent magnet type synchronous motor, wherein the dm-axis current compensation value is a value equal to or greater than zero and is a decreasing function of the absolute value of the torque . In the control device for the permanent magnet type synchronous motor according to any one of claims 5 to 10,
The controller for a permanent magnet type synchronous motor, wherein the d-axis current compensation value is a function of decreasing the absolute value of the speed of the permanent magnet type synchronous motor. In the control device for a permanent magnet type synchronous motor according to any one of claims 5 to 11,
When the absolute value of the speed of the permanent magnet synchronous motor is large, the first d-axis current command value is calculated by limiting the first d-axis current command value with a negative upper limit value. Control device for permanent magnet synchronous motor.

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