JP2009124871A - V/f control system of synchronous electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a V/f control system capable of suppressing and improving responses, such as transient vibration, even if a load disturbance occurs in a synchronous electric motor, such as a permanent synchronous electric motor that possesses low-inertial features. <P>SOLUTION: A filter averaging processing section 36 detects a DC average current from a DC bus bar of an inverter 4, a torque ripple estimating section 38 obtains a DC average power from the DC average current of the inverter and a DC voltage, obtains a torque estimated value from the DC average power and a frequency command value ω<SP>*</SP>, and removes the components which are close to DC from the value to obtain a torque ripple component ΔT. A stabilization gain setting device 39 executes correction at a correction value Δω, corresponding to ΔT to stabilize V/f so as to suppress the torque ripples. A stabilization gain setting device 40 obtains a voltage correction value Δv, corresponding to the torque ripple component ΔT, and executes feedback compensation with respect to a voltage command value V<SB>m</SB>of the inverter with the voltage correction value Δv. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a synchronous motor V / f control device, and more particularly to V / f stabilization control of a synchronous motor having a low inertia characteristic.

  Permanent magnet synchronous motors usually require the position sensor to detect the magnetic pole position information of the rotor. However, depending on the usage environment, it may be difficult to attach the position sensor, or the position may be reduced in order to reduce costs and avoid position sensor failure. Many sensorless control methods that can be driven without a sensor have been proposed.

  The V / f control method is a method of controlling the primary voltage of the motor to be constant according to the rotation speed, and basically has an open loop configuration in which no position sensor or current sensor is used. However, when the V / f control method is applied to a synchronous motor drive device, the magnetic pole position is not detected, so that an unstable control state is caused by a sudden change in the load, and there is a possibility of stepping out in some cases. high.

  FIG. 7 shows a driving apparatus for a synchronous motor using a general voltage source PWM inverter. In order to stabilize the apparatus without step-out when this apparatus is controlled by the V / f control method, the two-phase current of the synchronous motor 1 is detected by the AC current sensor 2, and the pulsation component included in the motor current is detected by the controller. 3, the control phase of the PWM inverter 4 is corrected. 5 is a DC voltage source of the PWM inverter 4, and 6 is a smoothing capacitor.

  As a stabilization method in this V / f control, the motor current detection value is the inverter output voltage reference γδ coordinate (the inverter voltage vector direction is the δ axis, and the inverter orthogonality with the phase delayed 90 degrees from the δ axis as the γ axis) There is a method of converting the pulsation component of the δ-axis current to a frequency command value and stabilizing it (for example, see Non-Patent Document 1). This method can cope with load fluctuations by feeding back current.

(A) of FIG. 8 is a block diagram of the V / f stabilization control of the synchronous motor proposed in Non-Patent Document 1 and the like. The controller 3 that becomes the V / f control device basically obtains the voltage command V ^* that becomes a desired voltage amplitude value from the frequency command value ω ^{* in the} f / V converter 31. This f / V conversion uses the ratio between the rated speed and the rated voltage of the driven synchronous motor. The integrator 32 obtains the phase θ of the inverter voltage command value by integrating the frequency command value ω ^* . The coordinate converter 33 converts the voltage command V ^* (vδ ^* ) and the voltage command vγ ^{* of the} phase θ and γ-axis components into a three-phase voltage command value of the PWM inverter 4. The PWM inverter 4 performs PWM control of the inverter by various PWM methods, for example, a general triangular wave comparison PWM method.

As a V / f stabilization control means, the coordinate converter 34 converts the motor currents i _u and i _w detected by the current sensor 2 into a coordinate based on the phase information θ of the output voltage of the PWM inverter, thereby converting the γ and δ axes. The current is converted into currents iγ and iδ, and the stabilization processing unit 35 obtains the correction frequency Δω using the δ-axis current iδ from the coordinate converter 34, and corrects the frequency command value ω ^* to ω1 ^* with the correction frequency Δω. For example, the stabilization processing unit 35 is configured as shown in FIG. 8B, and a high-pass filter 35A cuts a component close to direct current to extract only a pulsation component (correction frequency Δω), and a stabilization gain setting unit 35B. in determining the correction gain K _i.

  When the above-mentioned synchronous motor V / f stabilization method is applied to a low-inertia PM motor, an integrator is inserted in the feedback loop, so overshoot and vibration components remain for load fluctuations and speed fluctuations. It takes time. As another V / f stabilization control method that improves this phenomenon, a method is also proposed in which the pulsation component of the q-axis torque current is directly fed back to the inverter d-axis voltage (proportional term) to achieve a quick response stabilization control. (For example, see Non-Patent Document 2).

As a technique for eliminating the need for a sensor for detecting the motor current, there is a technique for detecting the DC current of the inverter with a shunt resistor or the like and calculating the motor current from this DC current (see Non-Patent Document 3, for example).
Ito, Toyosaki, Osawa “Performance improvement of V / f control of permanent magnet synchronous motor”, D. Theory, Vol. 122, No. 3, 2002 Yamamoto, Ono “V / f control method for low-inertia PM motors”, IEEJ Industrial Application Conference, 1-56, 2005 Fukumoto, Watanabe, Sone, and Hayashi “A Method of AC Current Calculation by Detecting DC Current in a Three-Phase PWM Inverter”, Electrical Engineering D, 127, 2, 2007

  In the V / f control device for a permanent magnet synchronous motor, the methods of Non-Patent Documents 1 and 2 described above detect a motor current (at least for two phases), extract a pulsation component, and frequency command in a direction to cancel the pulsation. Feedback control is performed to adjust values and voltage command values. This V / f control requires an AC current sensor, but in practice, an AC current sensor in a safety device such as a motor overcurrent protection can be used. However, in applications where low cost and downsizing are important, an alternating current sensor becomes a cause of high cost, and a problem of mounting space also occurs.

  In this respect, the method of Non-Patent Document 3 detects the DC current of the inverter with a single shunt resistor, and can reproduce the three-phase motor current from this DC current. V / f stabilization control with a block configuration as shown in FIG. 8 using the method of Document 1 or 2 can be considered. In addition, since an AC current sensor is not required, cost reduction can be realized. Furthermore, when overcurrent protection is performed using the voltage across the shunt resistor as DC current information, no additional shunt resistor is required.

  Here, the direct current of the PWM inverter has a waveform including a PWM pulse as shown in FIG. Since this instantaneous pulse current value has information of any phase of the alternating current, it can be grasped from the energization pattern of the PWM inverter. Therefore, in Non-Patent Document 3, A / D conversion is performed at a timing at which the pulse current value can be obtained, and the AC current value of the motor is estimated and reproduced based on the instantaneous current value. For this reason, in order to reproduce the AC three-phase current of the motor from the DC current of the PWM inverter, a high-speed A / D converter and complicated software calculation processing are required.

  In particular, in applications that increase the carrier frequency of PWM control or applications that require high-speed rotation drive, A / D conversion processing must also be performed at high speed, which increases costs and makes it difficult to reproduce motor current. It is predicted that

To solve these problems, average processing is performed using a low-pass filter that removes the PWM carrier component from the pulsed current of the inverter DC bus, and the pulsation component (frequency fluctuation) contained in this DC average current is suppressed. The frequency command value is corrected so that the DC average current is obtained by multiplying the DC average current of the inverter by the DC voltage detection value, and the pulsation component (frequency fluctuation) contained in this DC average power is suppressed. The present applicant has already proposed a V / f control device for correcting the value. In this proposal, the correction value Δω is obtained by lowering the output of the stabilization gain setter 35B as the frequency command value ω ^* increases, or the detected value of DC average current or DC average power is divided by the frequency command value ω ^*. It is also proposed that the estimated torque value is obtained, and a pulsation component obtained by cutting a component close to a direct current is extracted from the estimated torque value to correct the frequency command value ω ^* .

FIG. 10A shows a block configuration diagram of the stabilization control using the DC average power. In place of the AC current sensor 2 in FIG. 8, the DC bus current is detected by the shunt resistor 7, and the filter average processing unit (low-pass filter) from the voltage v _sh proportional to the inverter DC bus current detected by the shunt resistor 7. An averaged current i _dc averaged at 36 is obtained. This averaged current i _dc is an effective current as shown in FIG. The voltage detector 8 detects the DC voltage V _dc of the PWM inverter 4. The three-phase voltage command value generation unit 37 generates a three-phase voltage command V ^* for the PWM inverter 4 from the voltage command instantaneous value V _m and the phase θ. This arithmetic expression is as follows. Although the switching pattern generation method of the PWM inverter is arbitrary, for example, the voltage command value and the carrier wave are compared by a carrier comparison method to generate a PWM signal, and the PWM inverter and the electric motor are driven.

As shown in FIG. 10B, the stabilization processing unit 35 multiplies the DC voltage V _dc and the averaged current i _dc by a multiplier 35C to obtain a DC average power, and the DC average power is divided by a divider 35D. By dividing by the frequency command value ω ^* , an estimated torque value (T ^ = P / ω ^* ) is obtained and used as an input to the high-pass filter 35A. This stabilization process calculates the torque estimate value from the DC current / DC voltage detection value and the frequency command value, and corrects the frequency command value so as to suppress the torque pulsation component. Even in the above, stabilization control can always be performed based on the torque fluctuation, and more stable V / f control can be realized in the full speed / full load region according to the torque fluctuation of the synchronous motor.

Here, in the device structure of FIG. 10, to detect the torque pulsation to destabilize the V / f control, but by changing the frequency command value omega ^* to suppress the pulsation frequency command value .omega.1 ^* of Viewed from the resulting phase θ by integrating the phase corrected by the frequency feedback gain K _i is the response of a first-order lag (integral term). This first-order lag is not a problem for ordinary general motors, but for low-inertia motors with a small mechanical time constant (for example, motors that require ultra-high speed rotation), disturbances such as load torque fluctuations However, the compensation is delayed, and it takes time to settle the torque fluctuation, resulting in vibrational behavior. This is described in detail in Non-Patent Document 2.

  An object of the present invention is to provide a V / f control device for a synchronous motor that can suppress and improve a transient vibration response even when a load disturbance occurs in a synchronous motor such as a permanent magnet synchronous motor having low inertia characteristics. There is.

In order to solve the above-described problem, the present invention estimates a torque pulsation component from the DC average current of the inverter, and performs feedback compensation and correction on the magnitude of the voltage command instantaneous value V _m according to the torque pulsation. Feedback compensation for phase θ obtained by command integration, feedback compensation for both voltage command instantaneous value V _m and phase θ, and feedback compensation for voltage command value in the magnetic flux direction on the rotating coordinate Thus, it is characterized by the following configuration.

(1) The synchronous motor is driven by a voltage type inverter, and the inverter's DC bus current is averaged by a low-pass filter, and the inverter frequency command value ω ^* is set so as to suppress the pulsation component contained in the DC average current. In the synchronous motor V / f control device including the stabilization processing means for correction,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A stabilization gain setting unit that obtains a voltage correction value Δv corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage command instantaneous value V _m of the inverter with the voltage correction value Δv;
It is provided with.

(2) The synchronous motor is driven by a voltage-type inverter, and the inverter's DC bus current is averaged by a low-pass filter, and the inverter frequency command value ω ^* is set so as to suppress the pulsation component contained in the DC average current. In the synchronous motor V / f control device including the stabilization processing means for correction,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A stabilization gain setter that obtains a phase correction value Δθ corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage phase θ of the inverter with the phase correction value Δθ;
It is provided with.

(3) The synchronous motor is driven by a voltage type inverter, and the inverter's DC bus current is averaged by a low-pass filter, and the inverter frequency command value ω ^* is set so as to suppress the pulsation component contained in the DC average current. In the synchronous motor V / f control device including the stabilization processing means for correction,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A first stabilization gain setter that obtains a voltage correction value Δv corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage command instantaneous value V _m of the inverter with the voltage correction value Δv;
A second stabilization gain setter that obtains a phase correction value Δθ corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage phase θ of the inverter with the phase correction value Δθ;
It is provided with.

(4) The synchronous motor is driven by a voltage-type inverter, and the inverter's DC bus current is averaged by a low-pass filter, and the frequency command value ω ^* of the inverter is set so as to suppress the pulsation component contained in this DC average current. In the synchronous motor V / f control device including the stabilization processing means for correction,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A γ-axis voltage correction value Δvγ on the γδ rotation coordinate corresponding to the torque pulsation component ΔT is obtained, and feedback compensation is performed on the γ-axis voltage command value vγ1 ^* on the γδ rotation coordinate of the inverter with the γ-axis voltage correction value Δvγ. A stabilization gain setter to
It is provided with.

(5) The torque pulsation estimating unit obtains a torque estimated value T ^ from the frequency command value ω1 ^* obtained by correcting the frequency command value ω ^* by the stabilization processing means and the DC average power P, and the DC estimated from the torque estimated value T ^. The torque pulsation component ΔT is obtained by removing a component close to.

(6) The torque pulsation estimating unit removes the torque pulsation included in the frequency command value ω1 ^* obtained by correcting the frequency command value ω ^* by the stabilization processing unit, and the frequency command value ω1 ^* and the DC average power P From the torque estimation value T ^, a torque pulsation component ΔT is obtained by removing a component close to direct current from the torque estimation value T ^.

(7) the stabilizing processing means, characterized in that the gain K _i to lower the correction value Δω as the frequency command value omega ^* is high.

  (8) The stabilization processing unit extracts the pulsation component obtained by cutting a component close to a direct current from the estimated torque value of the torque pulsation estimation unit, and obtains the correction value Δω.

As described above, according to the present invention, the torque pulsation component is estimated from the DC average current of the inverter, and the frequency command of the frequency command that is feedback-compensated and corrected for the magnitude of the voltage command instantaneous value V _m according to the torque pulsation component. Feedback compensation for phase θ obtained by integration, feedback compensation for both voltage command instantaneous value V _m and phase θ, and feedback compensation for voltage command value in the magnetic flux direction on the rotating coordinate Even when a load disturbance occurs in a synchronous motor such as a permanent magnet synchronous motor having the above characteristics, transient vibration response can be suppressed and improved.

  In particular, the frequency command value is corrected so as to suppress the pulsation component (frequency fluctuation) contained in the inverter DC average current, or the DC average current is obtained by multiplying the inverter DC average current by the DC voltage detection value. This is effective for cost reduction when applied to a V / f control device that corrects a frequency command value so as to suppress a pulsation component (frequency fluctuation) included in average power.

(Embodiment 1)
FIG. 1 is a block diagram of a V / f control device for a synchronous motor showing the present embodiment. 10 differs from FIG. 10 in that feedback compensation for the voltage command value (instantaneous value) V _m is added in addition to feedback compensation for the frequency command value ω ^* based on torque pulsation estimation.

In FIG. 1, the torque pulsation estimating unit 38 obtains the DC average power P from the DC average current i _dc and the DC voltage detection value V _dc in the multiplier 38A, as shown in FIG. A torque estimated value (T ^ = P / ω ^* ) is obtained from the DC average power P and the frequency command value ω ^* , and the high-pass filter 38C obtains a torque pulsation component ΔT by removing a component close to DC from the torque estimated value. Stabilized gain setting unit 39, the correction gain K _i is set, it obtains the speed correction value Δω made to correspond to the torque ripple component ΔT calculated by the torque pulsation estimation unit 38. Note that the high-pass filter 38C may actually be provided with a low-pass filter that prevents the high-frequency component from increasing in gain.

The speed correction control by the torque pulsation estimation unit 38 and the stabilization gain setter 39 up to the above is the same as the configuration of FIG. In the present embodiment, a stabilization gain setting device 40 is added. The stabilization gain setter 40 obtains a voltage correction value Δv corresponding to the torque pulsation component ΔT estimated by the torque pulsation estimation unit 38 by multiplying the gain Kv by ΔT, and feeds back the correction value Δv to the voltage command instantaneous value V _m . Value.

With this configuration, when a disturbance occurs in the load torque, this is obtained as a torque pulsation component ΔT, a correction value Δv corresponding to this is obtained, and direct feedback is provided for the magnitude of the voltage command instantaneous value V _m. Giving. That is, in addition to the suppression of the torque pulsation by frequency feedback compensation K _i, it has given only to further compensation magnitude component of the voltage command instantaneous value V _m separate from the phase theta.

According to the present embodiment, the compensation effect for the magnitude of the voltage command value V _m can be adjusted with the gain Kv of the stabilization gain setter 40 separately from the compensation of the phase θ. Thus, especially for low inertia electric motor, after basically subjected to stabilization control of the primary delay by the gain K _i of frequency correction, the transient vibration response due to load disturbances, through the integrator 32 no voltage command value can be adjusted compensation amount (instantaneous value) gain of the feedback for V _m K _v.

(Embodiment 2)
FIG. 2 is a block diagram of a V / f control device for a synchronous motor showing the present embodiment. 1 is different from FIG. 1 in that a stabilization gain setting device 41 is provided instead of the stabilization gain setting device 40.

In the first embodiment, feedback compensation for the voltage command instantaneous value V _m is added to stabilize the transient vibration response due to the load disturbance. On the other hand, the present embodiment is different in that the stabilization gain setting unit 41 performs stabilization feedback compensation for the phase θ obtained in the integrator 32 by integrating the corrected frequency command value ω1 ^* .

As in the first embodiment, the stabilization is basically performed by the frequency feedback gain K _i , but as described above, since the feedback loop via the phase θ includes integration, the response becomes a first-order lag. Therefore, in this embodiment, a phase correction value Δθ having a gain Kθ with respect to the phase θ is obtained, and feedback compensation is directly performed using this phase correction value. Since this feedback loop does not include integration, a faster compensation response can be realized. In particular, when applied to a low-inertia motor, there is an improvement effect of suppressing vibration (reducing settling time) against a vibrational response due to a load disturbance.

(Embodiment 3)
In the present embodiment, the transient vibration with respect to the load disturbance is improved by combining the first embodiment and the second embodiment. A block configuration diagram is shown in FIG. 3, and stabilization feedback compensation of the voltage command instantaneous value V _m by the stabilization gain setting device 40 and stabilization feedback compensation of the phase θ by the stabilization gain setting device 41 are performed.

According to the present embodiment, the stabilization feedback compensation gain can be adjusted and determined separately for the phase θ and the voltage V _m , and there is a degree of freedom in the phase / voltage adjustment amount.

(Embodiment 4)
In the first to third embodiments, the feedback gain is given to the phase, the magnitude of the voltage command value, or both, so that there is a degree of freedom in the adjustment, but the adjustment items are increased.

  Therefore, in this embodiment, gains to be adjusted are collectively simplified. A block diagram of this embodiment is shown in FIG.

In general, in the control of a permanent magnet synchronous motor, consider an orthogonal two-axis dq coordinate system in which the magnetic flux direction of the permanent magnet is the d axis and the phase advanced 90 degrees with respect to the d axis is the q axis. On the other hand, an orthogonal two-axis γδ coordinate system is defined in which the estimated d-axis rotating at the frequency inside the controller is the γ-axis, and the phase advanced 90 degrees with respect to the γ-axis is the δ-axis. In FIG. 8, the inverter voltage command value V ^* is generated by defining the γδ rotation coordinates that rotate at the frequency command value ω1 ^* with the phase θ of the inverter voltage command as a reference.

The configuration shown in FIG. 4 is equivalent to the first to third embodiments with respect to frequency feedback compensation, filter averaging processing, torque pulsation estimation, and the like. The corrected frequency command value ω1 ^* is integrated by the integrator 32 to derive the phase θ of the voltage command, and this is used for conversion from the γδ coordinate to the three-phase alternating current by the coordinate converter 33. The coordinate converter 33 performs coordinate conversion using Vδ ^* , Vγ ^*, and voltage phase θ, and converts it to a three-phase voltage command value.

The conversion by the f / V converter 31 has been converted to the voltage command value (instantaneous value) V _m in the above-described embodiments, but here it is converted to the δ-axis voltage Vδ ^* in the γδ coordinate system. Since the conversion coefficient from the three-phase voltage command value Vm to the γδ coordinate is √ (3/2), it can be easily obtained.

With respect to the γ-axis voltage command value Vγ ^* , the γ-axis voltage correction value Δvγ corresponding to the torque pulsation component ΔT is fed back by stabilizing feedback compensation of the gain Kvγ by the stabilization gain setting machine 42. The original γ-axis voltage command value vγ1 ^* (normally vγ1 ^* = 0 for a surface magnet synchronous motor) and Δvγ are combined to generate the final γ-axis voltage command value vγ ^* .

Note that the sign of the stabilization control term added to vγ1 ^* is positive. The non-patent document 2 shows that fluctuation due to load torque is finally equivalent to voltage disturbance on the γ-axis. When a positive torque (current) is generated, a positive γ-axis voltage is generated. This is to suppress the change in torque (current).

  According to the present embodiment, by performing feedback compensation to the voltage vγ on the orthogonal two-axis rotational coordinate, both the phase and the magnitude can be performed by one gain adjustment. Therefore, adjustment becomes easy.

(Embodiment 5)
The torque pulsation estimation unit 38 in the first to fourth embodiments has the configuration shown in FIG. 1B, but in this embodiment, the torque estimation calculation is performed as shown in FIG. 5 in the configuration of the torque pulsation estimation unit 38. instead of using the frequency command value omega ^*, the torque estimation calculation using the frequency command value .omega.1 ^* after correction by the frequency feedback.

The correction command value ω1 ^{* obtained} by frequency feedback with respect to the original frequency command value ω ^* usually has an offset in the direction in which the fluctuation is normally suppressed in order to prevent step-out due to torque fluctuation. As a result, a slight offset error may occur between the original frequency command value ω ^* and the actual rotational speed. Although this influence is slight, in order to estimate the torque with a value closer to the actual rotational speed, in this embodiment, the torque estimation calculation is performed with a value closer to the actual speed by using the corrected frequency command value ω1 ^*. be able to.

(Embodiment 6)
In this embodiment, a low-pass filter for removing the torque pulsation included in the correction frequency command value ω1 ^* of the fifth embodiment is inserted. A configuration diagram of the torque pulsation estimating unit 38 is shown in FIG. 6, and the frequency command value ω1 ^* is input to the divider 38B through the low-pass filter 38D.

Since the frequency command value ω1 ^* corrected by the frequency feedback compensation is a command value that changes according to torque pulsation, it may become a vibration command value during a transient such as a load disturbance. Since this vibration component has a waveform that is to be compensated in a phase and magnitude shifted with respect to the torque pulsation, it interferes with the feedback compensation gain of each part and its phase / magnitude, and on the contrary, unstable vibration is generated. May cause.

Therefore, in this embodiment, a low-pass filter 38D that removes a transient torque pulsation component is inserted into the frequency command value ω1 ^* , and an average speed value is given to the torque estimation calculation. Thereby, unstable feedback compensation that may be caused by a transient pulsation of the corrected frequency command value ω1 ^* can be eliminated.

(Modification)
In the embodiments described above, the V / f of the synchronous motor that detects the torque pulsation from the DC average current of the inverter, the DC voltage detection value, and the frequency command value, and corrects the frequency command value so as to suppress the torque pulsation component. In the case of a control device, a V / f control device that averages the DC bus current of the inverter and corrects the frequency command value so as to suppress the pulsation component (frequency variation) included in the DC average current. Applying it produces the same effect. In this case, the torque pulsation estimation unit 38 in each embodiment is provided separately as a means for improving the transient vibration response due to the load disturbance together with the load stabilization gain setting units 40 to 42.

Similarly, a correction value Δω obtained by lowering the output of the stabilization gain setter 39 as the frequency command value ω ^* increases is obtained, or the detected value of DC average current or DC average power is divided by the frequency command value ω ^*. A torque estimation value is obtained, and a pulsation component obtained by cutting a component close to a direct current is extracted from the torque estimation value and applied to a V / f control device that corrects the frequency command value ω ^* .

1 is a block configuration diagram of a V / f control device for a synchronous motor showing Embodiment 1. FIG. FIG. 5 is a block configuration diagram of a synchronous motor V / f control device according to a second embodiment. FIG. 5 is a block configuration diagram of a synchronous motor V / f control device according to a third embodiment. FIG. 6 is a block configuration diagram of a synchronous motor V / f control device according to a fourth embodiment. FIG. 10 is a configuration diagram of a torque pulsation estimating unit according to a fifth embodiment. The block diagram of the torque pulsation estimation part of Embodiment 6. FIG. A synchronous motor drive device using a voltage-type PWM inverter. The conventional block diagram of the V / f stabilization control of a synchronous motor. The DC current waveform of the PWM inverter. The block block diagram of the stabilization control by DC average power. The current waveform figure of filter average processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Synchronous motor 2 AC current sensor 3 Controller 4 PWM inverter 5 DC voltage source 6 Smoothing capacitor 7 Shunt resistor 31 f / V converter 32 Integrator 36 Filter average process part 37 Three-phase voltage command value generation part 38 Torque pulsation estimation part 39, 40 Stabilization gain setting device

Claims (8)

A stable motor that drives a synchronous motor with a voltage-type inverter, averages the DC bus current of the inverter with a low-pass filter, and corrects the inverter frequency command value ω ^* so as to suppress the pulsation component contained in the DC average current In the synchronous motor V / f control device provided with the processing unit,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A stabilization gain setting unit that obtains a voltage correction value Δv corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage command instantaneous value V _m of the inverter with the voltage correction value Δv;
A V / f control device for a synchronous motor, comprising: A stable motor that drives a synchronous motor with a voltage-type inverter, averages the DC bus current of the inverter with a low-pass filter, and corrects the inverter frequency command value ω ^* so as to suppress the pulsation component contained in the DC average current In the synchronous motor V / f control device provided with the processing unit,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A stabilization gain setter that obtains a phase correction value Δθ corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage phase θ of the inverter with the phase correction value Δθ;
A V / f control device for a synchronous motor, comprising: A stable motor that drives a synchronous motor with a voltage-type inverter, averages the DC bus current of the inverter with a low-pass filter, and corrects the inverter frequency command value ω ^* so as to suppress the pulsation component contained in the DC average current In the synchronous motor V / f control device provided with the processing unit,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A first stabilization gain setter that obtains a voltage correction value Δv corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage command instantaneous value V _m of the inverter with the voltage correction value Δv;
A second stabilization gain setter that obtains a phase correction value Δθ corresponding to the torque pulsation component ΔT and performs feedback compensation on the voltage phase θ of the inverter with the phase correction value Δθ;
A V / f control device for a synchronous motor, comprising: A stable motor that drives a synchronous motor with a voltage-type inverter, averages the DC bus current of the inverter with a low-pass filter, and corrects the frequency command value ω ^* of the inverter so as to suppress the pulsation component contained in this DC average current In the synchronous motor V / f control device provided with the processing unit,
A DC average power P is obtained by multiplying the DC average current by the DC voltage of the inverter, a torque estimated value T ^ is obtained from the DC average power P and the frequency command value ω ^*, and a component close to DC is obtained from the torque estimated value T ^. A torque pulsation estimating unit for obtaining a torque pulsation component ΔT by removing;
A γ-axis voltage correction value Δvγ on the γδ rotation coordinate corresponding to the torque pulsation component ΔT is obtained, and feedback compensation is performed on the γ-axis voltage command value vγ1 ^* on the γδ rotation coordinate of the inverter with the γ-axis voltage correction value Δvγ. A stabilizing gain setter,
A V / f control device for a synchronous motor, comprising: The torque pulsation estimating unit obtains a torque estimated value T ^ from the frequency command value ω1 ^* obtained by correcting the frequency command value ω ^* by the stabilization processing unit and the DC average power P, and a component close to DC from the torque estimated value T ^. The V / f control device for a synchronous motor according to claim 1, wherein the torque pulsation component ΔT is obtained by removing the torque pulsation component ΔT. The torque pulsation estimating unit removes a torque pulsation included in the frequency command value ω1 ^* obtained by correcting the frequency command value ω ^* by the stabilization processing means, and estimates the torque from the frequency command value ω1 ^* and the DC average power P. The torque pulsation component ΔT is obtained by obtaining a value T ^ and removing a component close to a direct current from the estimated torque value T ^, V / of the synchronous motor according to any one of claims 1 to 4. f control device. It said stabilization means, the synchronous motor according to claim 1, characterized in that the gain K _i to lower the correction value Δω as the frequency command value omega ^* is high V / f control device.   The said stabilization process means extracts the pulsation component which cut | disconnected the component close | similar to direct current | flow from the torque estimated value of the said torque pulsation estimation part, and obtains said correction value (DELTA) omega. A V / f control device for a synchronous motor according to the item.

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