Power conversion device

Abstract

Provided is a power conversion device that achieves stable, highly accurate, and highly efficient control characteristics by suppressing speed pulsation of a driven motor and suppressing torque pulsation. A power conversion device for driving a magnet motor includes: a first filter unit that has a first-order system transfer function filter that varies in response to a pulsation component of the magnet motor, and that calculates a second speed estimation value from a speed command value and a first speed estimation value; a speed control unit that calculates a first torque current command value on the basis of the speed command value and the second speed estimation value; and a second filter unit that has a second order system transfer function filter that varies in response to the pulsation component, and that calculates a second torque current command value from the first torque current command value, the power supplied to the magnet motor being controlled on the basis of the second torque current command value.

Description

Technical Field

[0001] The invention relates to a power conversion device. Background Art

[0002] Patent Document 1 is known as a technique for controlling load torque pulsation in a compressor system based on position sensorless control. Patent Document 1 describes a technique for extracting a periodic pulsation component of the difference between the motor speed and the speed command using a resonant filter, and correcting the output of the speed control, that is, the torque current command value, using the pulsation component extracted by the resonant filter.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-191737 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The technology described in Patent Document 1 can suppress the speed pulsation of the motor by adding the output of the resonant filter and the output of the speed control, but does not mention suppressing the torque pulsation.

[0008] An object of the present invention is to provide a power conversion device that achieves stable, high-precision, and high-efficiency control characteristics by suppressing speed pulsation and torque pulsation of a driven motor.

[0009] Technical solutions to the problem

[0010] The present invention provides a power conversion device for driving a magnet motor, comprising: a first filter unit having a first-order system transfer function filter that changes in response to a pulsation component of the magnet motor, and calculating a second speed estimation value based on a speed command value and a first speed estimation value;

[0011] A speed control unit that calculates a first torque current command value based on the speed command value and a second speed estimated value; and

[0012] The second filter unit has a second-order system transfer function filter that changes in response to the pulsation component, and calculates a second torque current command value based on the first torque current command value.

[0013] Here, the power supplied to the magnet motor is controlled based on the second torque current command value.

[0014] Effects of the Invention

[0015] According to the present invention, it is possible to realize stable, highly accurate, and highly efficient control characteristics by suppressing speed pulsation and torque pulsation of a driven electric motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the power conversion device of Example 1.

[0017] Figure 2 It is a structural diagram of the second-order system transfer function filter calculation unit of Example 1.

[0018] Figure 3 It is a structural diagram of the first-order system transfer function filter calculation unit of Example 1.

[0019] Figure 4 It is a diagram showing the frequency characteristics of the second-order system transfer function filter calculation unit in two suppression control modes.

[0020] Figure 5 This is a diagram showing control characteristics at 10% of the base speed when Example 1 is not used.

[0021] Figure 6 This is a diagram showing control characteristics at 10% of the base speed when a second-order system transfer function filter calculation unit is used (control mode for suppressing speed pulsation).

[0022] Figure 7 This is a diagram showing control characteristics at 50% of the base speed when a second-order system transfer function filter calculation unit is used (control mode for suppressing speed pulsation).

[0023] Figure 8 This is a diagram showing the frequency characteristics of a speed control system when a second-order system transfer function filter calculation unit is used (control mode for suppressing speed pulsation).

[0024] Fig. 9 This is a diagram showing the frequency characteristics of the speed control system at 50% of the base speed when a second-order system transfer function filter calculation unit (control mode for suppressing speed pulsation) and a first-order system transfer function filter calculation unit are used.

[0025] Fig.10 This is a diagram showing control characteristics at 50% of the fundamental frequency when a second-order system transfer function filter calculation unit (control mode for suppressing speed pulsation) and a first-order system transfer function filter calculation unit are used.

[0026] Fig.11 This is a diagram showing control characteristics at 90% of the base speed when the second-order system transfer function filter calculation unit is not used (control mode for suppressing torque ripple).

[0027] Fig.12 This is a diagram showing control characteristics at 90% of the base speed when a second-order system transfer function filter calculation unit is used (control mode for suppressing torque ripple).

[0028] Fig.13 It is a structural diagram for verifying the embodiment.

[0029] Fig.14 A is a diagram showing the current waveform (10% of the base speed) of the q axis used for verification. Fig.14 B is a diagram showing a q-axis current waveform (90% of the base speed) used for verification.

[0030] Fig.15 It is a structural diagram of the power conversion device of Example 2.

[0031] Fig.16 It is a structural diagram of the second-order system transfer function filter calculation unit of Example 2.

[0032] Fig.17 It is a structural diagram of the power conversion device of Example 3.

[0033] Fig.18 It is a structural diagram of the second-order system transfer function filter calculation unit of Example 3.

[0034] Fig.19 It is a structural diagram of the first-order system transfer function filter calculation unit of Example 3.

[0035] Fig. 20 It is a structural diagram of another power conversion device according to Example 4.

[0036] Fig.21 It is a structural diagram of another power conversion device of Example 5. DETAILED DESCRIPTION

[0037] The present embodiment will be described in detail below using the drawings. The same reference numerals are given to common structures in the various figures. In addition, the various embodiments described below are not limited to the illustrated examples.

[0038] Example 1

[0039] Figure 1 A diagram showing the structure of a power conversion device and a magnet motor according to the first embodiment.

[0040] The magnet motor 1 outputs a motor torque obtained by synthesizing a torque component based on the magnetic flux of the permanent magnet and a torque component based on the inductance of the armature winding.

[0041] The output of power converter 2 is related to the three-phase AC voltage command value v u * 、v v* 、v w * The output voltage value and the output frequency value of the magnet motor 1 are changed in proportion to the voltage value.

[0042] The DC power supply 3 supplies a DC voltage to the power converter 2 .

[0043] The current detector 4 outputs the three-phase AC current i of the magnet motor 1 u 、i v 、i w The detection value i uc 、i vc 、i wc In addition, the current detector 4 can also detect the AC current of two phases, for example, the u phase and the w phase, among the three phases of the magnet motor 1, and according to the AC condition (i u +i v +i w =0) to follow i v =-(i u +i w ) to obtain the AC current of the v phase. This embodiment adopts an example in which the current detector 4 is set inside the power conversion device, but it can also be set outside the power conversion device.

[0044] The coordinate conversion unit 5 is based on the three-phase AC current i u 、i v 、i w The detection value i uc 、i vc 、i wc and the phase estimated value θ dc , output the current detection value i of the d-axis and q-axis dc 、i qc .

[0045] The speed control calculation unit 6 obtains the speed command value ω r * and the new estimated speed value ω dc ′ The first torque current command value i is calculated and output based on the difference (deviation). q0 * .

[0046] The second-order system transfer function filter calculation unit 7 outputs the first torque current command value i q0 * and speed command value ω r * and the second torque current command value i obtained by calculating the second-order system transfer function filter of the Laplace operator s q * .

[0047] The first-order system transfer function filter calculation unit 8 calculates the speed estimated value ω based on the speed estimated value ω. dc The first-order system transfer function filter of the Laplace operator s outputs a new speed estimation value ω dc ′ .

[0048] The vector control calculation unit 9 outputs the current command value i based on the d-axis. d * and the q-axis current command value (second torque current command value) i q * , current detection value i dc 、i qc 、New estimated speed value ω dc ′ The voltage command values ​​v of the d-axis and q-axis calculated by using the circuit parameters of the magnet motor 1 are dc ** 、v qc ** .

[0049] The phase error estimation calculation unit 10 uses the control axis d c Axis and q c The voltage command value v of the axis dc ** 、v qc ** , speed estimation value ω dc , current detection value i dc 、i qc and the circuit parameters of the magnet motor 1, the phase θ of the output control shaft dc The phase θ with the magnet of the magnet motor 1 d The deviation is the estimated value of the phase error Δθ c .

[0050] The frequency and phase estimation calculation unit 11 calculates the estimated value Δθ of the phase error based on the estimated value Δθ of the phase error. c , output speed estimated value ω dc and the phase estimated value θ dc .

[0051] The coordinate conversion unit 12 is based on d c Axis and q c The voltage command value v of the axis dc ** 、v qc ** And the phase estimated value θ dc , output three-phase AC voltage command value v u * 、v v * 、v w* .

[0052] First, the basic operation of the sensorless vector control method using the second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8, which is a feature of this embodiment, will be described.

[0053] The speed control calculation unit 6 is set so that a new speed estimated value ω described later is dc ′ Following speed command value ω r * By proportional control and integral control, the first q-axis current command value i is calculated according to (Equation 1) q0 * .

[0054]

[0055] Here,

[0056] K sp : Proportional gain of speed control, K si : integral gain of speed control, s: Laplace operator

[0057] Next, the second-order system transfer function filter calculation unit 7 which is one of the features of the present invention will be described.

[0058] exist Figure 2 , a configuration diagram of the second-order system transfer function filter calculation unit 7 is shown.

[0059] In the second-order system transfer function filter calculation unit 7, the first q-axis current command value i is used in the second-order system transfer function filter 71 of the Laplace operator s. q0 * , the mechanical angular velocity of the magnet motor 1, i.e., the pulsation component ω n and the attenuation ratio ζ a , b , calculate the second torque current command value i according to (Formula 2) q * .

[0060]

[0061] The mechanical angular velocity conversion unit 72 uses the pole pair number P of the magnet motor 1 m The pulsating component ω to be set for the second-order system transfer function filter 71 is calculated according to (Equation 3) n .

[0062]

[0063] The control mode selection unit 73 selects the speed command value ω according to the speed command value ω.r * The magnitude of is used to determine whether the motor is in a low speed region or a high speed region. When the motor is determined to be in a low speed region, the “control mode for suppressing speed pulsation” of the magnet motor 1 is selected, and when the motor is determined to be in a high speed region, the “control mode for suppressing torque pulsation” is selected, thereby selecting one of them.

[0064] When the "speed pulsation suppression control mode" is selected, the attenuation ratio selection unit 74 sets the attenuation ratio z related to the speed pulsation suppression control. a , b When the "torque pulsation suppression control mode" is selected, set the attenuation ratio ζ related to the speed pulsation suppression control a , b The second-order system transfer function filter 71 has a pulsating component ω n As a parameter, it is changed accordingly according to the pulsation component.

[0065] Figure 3 This figure shows a block of the first-order system transfer function filter calculation unit 8 .

[0066] In the first-order system transfer function filter calculation unit 8, the speed command value ω is used in the first-order system transfer function filter 81 of the Laplace operator s. r * , speed estimation value ω dc , Lead time constant T a and the lag time constant T b , calculate the new speed estimation value ω according to (Equation 4) dc ′ .

[0067]

[0068] In the first-order system transfer function filter calculation unit 8, the leading time constant T is calculated according to (Equation 5) a .

[0069]

[0070] Lead time constant T a As long as the mechanical angular velocity, i.e. the pulsating component ω n The lag time constant T b As long as T a For example, it can be a time constant corresponding to the response frequency of the current control (hereinafter referred to as the response time constant of the current control). According to (Equation 5), the lead time constant T in the first-order system transfer function filter 81 is a The pulsation component of the magnet motor changes accordingly. The first-order leading time constant T can also be modified according to the speed command value. a .

[0071] Figure 4 The frequency characteristics of the two control modes in the second-order system transfer function filter calculation unit are shown. Figure 2 The input i shown q0 * To output i q * Gain and phase characteristics.

[0072] The "speed pulsation suppression control mode" is set to n The gain is maximum at the point where the torque ripple suppression control mode is set to the pulsation component ω n The gain is extremely small at this point. This characteristic can be explained by the above attenuation ratio ζ a , b is obtained by setting.

[0073] In the vector control calculation unit 9, first, a setting value R of the winding resistance as a circuit parameter of the permanent magnet motor 1 is used. * , d-axis inductance setting value L d * , q-axis inductance setting value L q * , setting value of induction voltage coefficient K e * ,d c Axis and q c Axis current command value i d * 、i q * And the estimated speed value ω dc , according to (Equation 6) output d c Axis and q c The voltage reference value v of the axis dc * 、v qc * .

[0074]

[0075] Here, T acr : Response time constant of current control

[0076] Next, the current detection value i of each component is dc 、i qc Follow c Axis and q c Axis current command value i d * 、i q *By using proportional control and integral control, d is calculated according to (Equation 7) c Axis and q c Shaft voltage correction value Δv dc , Δv qc .

[0077]

[0078] Here,

[0079] K pd :d c Proportional gain of the axis current control, K id :d c Integral gain of the axis current control

[0080] K pq :q c Proportional gain of the axis current control, K iq :q c Integral gain of the axis current control

[0081] Then, according to (Equation 8), d c Axis and q c The voltage command value v of the axis dc ** 、v qc ** .

[0082]

[0083] In the phase error estimation operation unit 10, based on d c Axis and q c The voltage command value v of the axis dc ** 、v qc ** , current detection value i dc 、i qc , speed estimation value ω dc and the circuit parameters of the magnet motor 1 (R * , L q * ), and according to the extended back electromotive force (EEMF) formula (Equation 9), the estimated value of the phase error Δθ is calculated c .

[0084]

[0085] The frequency and phase estimation calculation unit 11 uses the estimated value Δθ of the phase error as c Follow its command value Δθ c *(=0), through P (proportional) + I (integral) control, the speed estimation value ω is calculated according to (Equation 10) dc In addition, the frequency and phase estimation calculation unit 11 calculates the phase estimation value θ according to (Equation 11) through I (integral) control. dc .

[0086]

[0087] Here, Kp pll : Proportional gain of PLL control, Ki pll : PLL control integral gain

[0088] Next, the principle of the control characteristics of the present invention with high stability, high precision and high efficiency is explained. Figure 5 , the control characteristics when the second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8 of this embodiment are not used in the low speed range and there is a load pulsating torque are shown. The pulsating load torque is a total of 100% of the maximum DC component 50% and the maximum pulsating component 50%, and is applied in a ramp shape.

[0089] Figure 5 This is the simulation result when the speed command value is set to 10% of the base speed. In this figure, the upper part shows the load pulsating torque and the motor torque, and the lower part shows the speed command value and the motor speed. At this time, the maximum value of the load pulsating torque is about 60%, but the motor speed decelerates to near zero near time A in the figure, and the magnet motor 1 loses step and becomes stopped.

[0090] exist Figure 6 The control characteristics when the second-order system transfer function filter operation unit 7 of this embodiment is used but the first-order system transfer function filter operation unit 8 is not used and the "speed pulsation suppression control mode" is selected are shown in FIG. Figure 5 The simulation results are also shown when the speed command is set to 10% of the base speed. The maximum value of the load pulsation torque increases to 100% near time B, but due to the effect of the second-order system transfer function filter calculation unit 7, the gain of the speed pulsation component increases, so the motor torque follows the load pulsation torque, and the speed pulsation amplitude can be reduced to approximately zero. At 10% of the base speed, even without using the first-order system transfer function filter calculation unit 8, high-stability and high-precision operation can be achieved.

[0091] In addition, Figure 7, the control characteristics when there is load pulsating torque when the second-order system transfer function filter calculation unit 7 of this embodiment is used but the first-order system transfer function filter calculation unit 8 is not used at 50% of the base speed. In this figure as well, the upper part shows the load pulsating torque and the motor torque, and the lower part shows the speed command value and the motor speed. When the base speed reaches 50%, the control characteristics when the base speed reaches 10% are different. Figure 4 Compared with the time instant 2, the motor torque does not follow the load pulsating torque, and the amplitude of the motor torque gradually increases from time C to time D.

[0092] exist Figure 8 , the frequency characteristics when the second-order system transfer function filter operation unit 7 of the present embodiment is used but the first-order system transfer function filter operation unit 8 is not used, and the "speed pulsation suppression control mode" is selected are shown. Figure 8 The horizontal axis is the frequency of the magnet motor, which is obtained from the speed command value ω r * To the estimated speed value ω dc Gain and phase characteristics.

[0093] The gain characteristic of the upper part is in the pulsating component ω n The gain is maximum at point E, and at frequency point F where the gain is 0dB (gain = 1), i.e., the crossover frequency, the lower phase characteristic is -180deg near point G. Therefore, it can be seen that the phase margin of the control system is insufficient and the speed control system is unstable.

[0094] Fig. 9 The frequency characteristics when the second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8 of the present embodiment are used and the “speed pulsation suppression control mode” is selected are shown. Fig. 9 The horizontal axis is the frequency of the magnet motor, which is obtained from the speed command value ω r * To the estimated speed value ω dc Gain and phase characteristics.

[0095] The gain characteristic of the upper part is in the pulsating component ω n The gain is maximum at point H, and at the frequency point I where the gain is 0 dB (gain = 1), i.e., the crossover frequency, the lower phase characteristic is near point J, and the phase margin is improved. That is, it can be seen that at 50% of the base speed, the speed control system is relatively stable due to the effect of the first-order system transfer function filter operation unit 8.

[0096] Fig.10This is the simulation result when the second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8 of this embodiment are used at 50% of the base speed, and the "speed pulsation suppression control mode" is selected. The maximum value of the load pulsation torque increases to 100% at time K, but because the gain of the speed pulsation component increases, the motor torque follows the load pulsation torque and the speed pulsation amplitude can be reduced to approximately zero. By using the first-order system transfer function filter calculation unit 8, high-stability and high-precision operation can be achieved.

[0097] That is, when the motor speed increases, the frequency characteristics of the speed control system need to be improved, so the first-order system transfer function filter calculation unit 8 becomes necessary. The reason is that the frequency characteristics of the speed control system are affected by the response frequency F set in the frequency and phase estimation calculation unit 11. PLL The influence of changing the control frequency band.

[0098] If the estimated velocity value ω dc Size |ω dc |With response frequency F PLL If the relationship of (Equation 12) is satisfied, a first-order system transfer function filter operation unit 8 may be used.

[0099]

[0100] Fig.11 The control characteristics when there is load pulsation torque when the second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8 of this embodiment are not used at 90% of the base speed. This is a simulation result when the speed command value is set to 90% of the base speed. Fig.11 The upper part indicates the load pulsating torque and the motor torque, and the lower part indicates the speed command value and the motor speed. When the speed reaches 90% of the base speed, it is the same as when it reaches 10% ( Figure 5 ) compared to the pulsation of the motor torque. This is because it leaves the control band of the speed control operation unit 6.

[0101] Due to the influence of the pulsating load torque, the maximum value of the motor torque at time L in the figure is about 72%. At this time, based on the motor speed ω r and torque τ m , the output P of the motor is generated according to the relationship (Formula 13).

[0102]

[0103] Therefore, in the high-speed region, the pulsation of the motor output P is large, and the motor efficiency is poor. Fig.12FIG. 2 shows the control characteristics when the second-order system transfer function filter operation unit 7 of this embodiment is used and the "torque ripple suppression control mode" is selected. Fig.11 Similarly, the speed command value is set to 90% of the base speed. n The gain is reduced, so the maximum value of the motor torque becomes 52%, which is Fig.11 In comparison, the torque pulsation amplitude is greatly reduced from 22% (=72-50) to 2% (=52-50), the pulsation of the output P of the motor is reduced, and stable and efficient operation can be achieved.

[0104] It can be seen that the effect of the present invention is significant by selecting the “control mode for suppressing speed pulsation” in the low speed range of the motor and selecting the “control mode for suppressing torque pulsation” in the high speed range.

[0105] In this embodiment, for example, the speed command value ω r * The size of 10% or 50% of the base speed is used as the low speed area, and the range above it is used as the high speed area. However, the range where the magnet motor 1 loses step due to the load pulsating torque can also be used as the low speed area, and the range above it can be used as the high speed area. Furthermore, the low speed area and the high speed can also be uniquely determined according to the size of the speed command value. In addition, it is also possible to determine the low speed area and the high speed according to the speed command value ω. r * Or the estimated speed value ω dc The above attenuation ratio ζ is changed accordingly a , b , thereby deliberately controlling the motor speed ω r and the motor torque τ m Pulse width.

[0106] According to this embodiment, for example, when a compressor system is driven by a magnet motor, by selecting a "control mode for suppressing speed pulsation" in the low-speed region of the magnet motor and selecting a "control mode for suppressing torque pulsation" in the high-speed region, a power conversion device with high stability, high precision, and high efficiency control characteristics from the low-speed region to the high-speed region can be realized.

[0107] Furthermore, according to the present embodiment, when the compressor system is driven by the electric motor, it is possible to freely suppress the pulsation of the torque and speed of the electric motor caused by the load torque pulsation that changes with one mechanical angle rotation.

[0108] Here, use Fig.13 A verification method in the case of adopting this embodiment will be described. A voltage detector 21 and a current detector 22 are installed in a power conversion device 20 that drives a magnet motor 1 , and an encoder 23 is installed on the shaft of the magnet motor 1 .

[0109] The output of the voltage detector 21, that is, the voltage detection value of the three-phase AC (v uc 、v vc 、v wc ), three-phase AC current detection value (i uc 、i vc 、i wc ) and the encoder output, i.e., position θ, are input to the vector voltage / current component calculation unit 24 to calculate the vector voltage component v dc 、v qc , vector current component i dc 、i qc , and the speed detection value ω obtained by differentiating the position θ rc .

[0110] The speed command value ω provided to the controller of the power converter 2 r * For example, the speed is set to about 50% of the base speed, and the compressor in which the magnet motor 1 is built is driven.

[0111] If the speed detection value ω rc Size |ω rc | and the response frequency F set in the power conversion device 20 PLL If the relationship of (Equation 14) is satisfied, it is highly likely that the first-order system transfer function filter calculation unit 8 is used.

[0112]

[0113] exist Fig.14 A shows that the speed command value ω r * The vector current component i when the compressor having the magnet motor 1 built in is driven is set to 10% of the base speed. qc The waveform of the vector current component i qc Proportional to the load pulsating torque, so the vector current component i qc It is a waveform that decreases to approximately zero.

[0114] exist Fig.14 In B, it is shown that the speed command value ω r * The vector current component i when the compressor having the magnet motor 1 built in is driven at 90% of the base speed is set qc The waveform of the vector current component i qc It has nothing to do with the load pulsation torque, so i qc It is almost a DC component, and the pulsating component is less than 10% of the DC component.

[0115] If the speed command is set at every 10% of the base speed and the same test is performed, the states of the control modes of "control mode for suppressing speed pulsation" and "control mode for suppressing torque pulsation" will become clear. qc The waveform of the speed detection value ω can also be observed rc waveform.

[0116] Example 2

[0117] Fig.15 2 is a structural diagram of a power conversion device and a magnet motor according to Embodiment 2. Embodiment 1 adopts such a method that the attenuation ratio ζ set in the second-order system transfer function filter 71 of the second-order system transfer function filter calculation unit 7 a , b , using the speed command value, it switches to the "control mode for suppressing speed pulsation" in the low-speed area and switches to the "control mode for suppressing torque pulsation" in the high-speed area.

[0118] The present embodiment adopts a method of preparing two second-order system transfer function filters 7a1 and 7a5 in the second-order system transfer function filter calculation unit 7a, and switching them in accordance with the low-speed region and the high-speed region, respectively. Fig.15 The magnet motor 1 in the speed control operation unit 6, the first-order system transfer function filter operation unit 8 and the coordinate conversion unit 12 are Figure 1 Same. Fig.16 , the structure of the second-order system transfer function filter calculation unit 7a is shown.

[0119] In the second-order system transfer function filter calculation unit 7a, the first q-axis current command value i is used in the second-order system transfer function filter 7a1 of the Laplace operator s. q0 * , pulsation component ω n 、The attenuation ratio of the "speed pulsation suppression control mode" ζ a1 , b1 , calculate the second torque current command value i according to (Equation 15) q1 * .

[0120]

[0121] Furthermore, in the second-order system transfer function filter 7a5, the first q-axis current command value i q0 * , pulsation component ω n 、The attenuation ratio of the "torque ripple suppression control mode" ζ a2 , b2 , calculate the second torque current command value i according to (Equation 16) q2* .

[0122]

[0123] The mechanical speed conversion unit 7a2 uses the number of pole pairs P of the magnet motor 1 m The value of is calculated according to the above (Equation 3) to set the pulsation component ω for the second-order system transfer function filter 7a1 n .

[0124] The control mode selection unit 7a3 selects the speed command value ω according to the speed command value ω. r * The low-speed area and high-speed area are determined by the size of. When it is determined to be a low-speed area, select "control mode to suppress speed pulsation", and when it is determined to be a high-speed area, select "control mode to suppress torque pulsation".

[0125] When the control mode selection unit 7a3 selects the "speed pulsation suppression control mode", the filter switching unit 7a4 switches the output of the second-order system transfer function filter 7a1, that is, i q1 * As the q-axis current command value i q * In addition, when the "torque ripple suppression control mode" is selected, the output of the second-order system transfer function filter 7a5, i q2 * As the q-axis current command value i q * This embodiment prepares two second-order system transfer function filters and switches them in the low-speed region and the high-speed region. This embodiment can also achieve stable, high-precision, and high-efficiency control characteristics in the same manner as the first embodiment.

[0126] Example 3

[0127] Fig.17 1 is a structural diagram of a power conversion device and a magnet motor according to Embodiment 3. Embodiment 1 adopts such a method that the attenuation ratio ζ set in the second-order system transfer function filter 71 of the second-order system transfer function filter calculation unit 7 a , b , use the speed command value to switch between the "control mode for suppressing speed pulsation" in the low-speed area and the "control mode for suppressing torque pulsation" in the high-speed area.

[0128] In this embodiment, the power (electric power) value is used to switch to the "control mode for suppressing speed pulsation" in the low power area, and to switch to the "control mode for suppressing torque pulsation" in the high power area. Fig.17 The magnet motor 1, the speed control operation unit 6, the phase error estimation operation unit 10, the coordinate conversion unit 12 and Figure 1The constituent elements are the same.

[0129] In the vector control calculation unit 9a, in addition to the calculations of (Equation 6) to (Equation 8), d c Axis and q c The voltage command value v of the axis dc ** 、v qc ** , current detection value i dc 、i qc , the inner product of the power of the magnet motor 1, that is, the effective power Pa, is calculated according to (Equation 17).

[0130]

[0131] Fig.18 7b1, 7b2, 7b4 and Figure 2 The second-order system transfer function filter 71, the mechanical angular velocity conversion unit 72, and the attenuation ratio selection unit 74 shown are the same, and their description is omitted.

[0132] The control mode selection unit 7b3 determines the low power region and the high power region according to the size of the effective power Pa. When it is determined to be in the low power region, the "control mode for suppressing speed pulsation" is selected, and when it is determined to be in the high power region, the "control mode for suppressing torque pulsation" is selected. This embodiment switches between the low power region and the high power region, and using this embodiment can also achieve high stability, high precision, and high efficiency control characteristics in the same way as in the first embodiment.

[0133] Here, in the second-order system transfer function filter 7b1 of the second-order system transfer function filter calculation unit 7b, the attenuation ratio ζ is switched between the low power region and the high power region. a , b However, as in Example 2, two second-order system filters may be equipped and used in the low-power region and the high-power region respectively.

[0134] exist Fig.19 The module of the first-order system transfer function filter operation unit 8a is shown in FIG. Figure 3 The first-order system transfer function filter 81 shown is the same, and its description is omitted.

[0135] 8a2 is the coefficient K, which is multiplied by the effective power Pa to calculate the pulsation component ω n The first-order leading time constant T can also be modified according to the power information. a .

[0136] Example 4

[0137] Fig. 201 is a structural diagram of a power conversion device, an IOT controller, and a magnet motor according to Embodiment 4. In Embodiments 1 to 3, the attenuation ratio ζ of the second-order system transfer function filter calculation unit 7 is set in the controller (microcomputer, etc.) of the power converter. a , b , the leading time constant T of the first-order system transfer function filter operation unit 8 a , and the switching speed ω between the "control mode for suppressing speed pulsation" and the "control mode for suppressing torque pulsation" chg Or switch the power value.

[0138] In this embodiment, the controlled state quantity (such as voltage command value and current detection value, phase error and first speed estimation value or second speed estimation value) is fed back to the IOT controller 31 as the upper device. Then, the IOT controller 31 feeds back the above-mentioned attenuation ratio ζ after machine learning. a , b , Lead time constant T a and switching speed ω chg The second-order system transfer function filter calculation unit 7 and the first-order system transfer function filter calculation unit 8 are reset.

[0139] Fig. 20 The magnet motor 1 to the coordinate conversion unit 12 and Figure 1 31 is an IOT controller that performs machine learning.

[0140] By using this embodiment, it is also possible to realize high stability, high precision, and high efficiency control characteristics without adjustment, similarly to the first embodiment.

[0141] Example 5

[0142] Fig.21 1 is a block diagram of a power conversion device, a host device, and a magnet motor according to Embodiment 5. This embodiment is applied to a magnet motor drive system. In the figure, the magnet motor 1, the coordinate conversion unit 5 to the coordinate conversion unit 12 as components and Figure 1 The elements are the same.

[0143] As Figure 1 The magnet motor 1 of the components is driven by the power conversion device 20. In the power conversion device 20, Figure 1 The coordinate conversion unit 5 to the coordinate conversion unit 12 constitute the control unit 20a.

[0144] The control unit 20a is composed of a semiconductor integrated circuit (calculation control unit) such as a microcomputer (microcomputer) or a DSP (Digital Signal Processor). It is also possible to use hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array) to constitute a part or all of the functions of the control unit 20a. The CPU (Central Processing Unit) of the control unit 20a reads the program stored in a recording device such as a memory and executes the processing of each unit such as the coordinate conversion unit 5.

[0145] Figure 1 The power converter 2 to the current detector 4 are implemented as hardware. In addition, the "low speed area / high speed area switching speed 26" of the control unit 20a can be set and changed by a higher-level device such as a digital operator 20b, a personal computer 28, a tablet computer 29, and a smart phone 30. chg ", " ", "The attenuation ratio of the low speed area / high speed areaζ a , b , time constant T a " and other parameters.

[0146] By applying this embodiment to a compressor system driven by a magnet motor, high stability, high precision, and high efficiency control characteristics can be achieved even in position sensorless vector control. chg ", " ", "The attenuation ratio of the low speed area / high speed areaζ a , b , time constant T a "27 can also be set on a field bus such as a programmable logic controller, a local area network connected to a computer, an IOT controller, etc.

[0147] Furthermore, in this embodiment, the case where the embodiment 1 is used is disclosed, but the embodiments 2 to 4 may also be used.

[0148] According to the present embodiment, the parameters set for the first-order system transfer function filter calculation unit and the second-order system transfer function filter calculation unit can be set and changed from the outside.

[0149] In the first to fifth embodiments, according to the current command value i d * 、i q * and the current detection value i dc 、i qc Generate voltage correction value Δv dc , Δv qc, and perform the operation shown in (Equation 8) of adding the voltage correction value to the voltage reference value of the vector control. However, it is not limited to this, and it is also possible to use the current command value i d * 、i q * and the current detection value i dc 、i qc The intermediate current command value i shown in (Equation 18) used in the vector control operation is generated. d ** 、i q ** , using the estimated velocity value ω dc The vector control operation shown in (Equation 19) is performed using the circuit parameters of the magnet motor 1.

[0150]

[0151] Here,

[0152] K pd1 :d c Proportional gain of the axis current control, K id1 :d c The integral gain of the axis current control,

[0153] K pq1 :q c Proportional gain of the axis current control, K iq1 :q c The integral gain of the axis current control,

[0154] T d : Electrical time constant of d-axis (L d / R), T q : q-axis electrical time constant (L q / R)

[0155]

[0156] Alternatively, according to the current command value i d * 、i q * and the current detection value i dc 、i qc , use (Equation 20) to generate the d used in vector control calculation c Voltage correction value Δv of the proportional operation component of the axis d_p * ,d c Voltage correction value Δv of the integral operation component of the axis d_i * ,q c Voltage correction value Δv of the proportional operation component of the axisq_p * ,q c Voltage correction value Δv of the integral operation component of the axis q_i * Then, the speed estimated value ω is used. dc The vector control operation shown in (Equation 21) of the circuit parameters of the magnet motor 1 is performed.

[0157]

[0158] Here,

[0159] K pd2 :d c Proportional gain of the axis current control, K id2 :d c The integral gain of the axis current control,

[0160] K pq2 :q c Proportional gain of the axis current control, K iq2 :q c Integral gain of the axis current control

[0161]

[0162] Alternatively, you can use d c Axis current command value i d * and q c Shaft current detection value i qc The first-order lag signal i qctd , speed estimation value ω dc and the circuit parameters of the magnet motor 1, and perform the vector control operation shown in (Equation 22).

[0163]

[0164] In the first to fifth embodiments, the switching element constituting the power converter 2 may be a Si (silicon) semiconductor element or a wide bandgap semiconductor element such as SiC (silicon carbide) or GaN (gallium nitride).

[0165] Description of Reference Numerals

[0166] 1 ... magnetic motor, 2 ... power converter, 3 ... direct current power supply, 4 ... current detector, 5 ... coordinate conversion unit, 6 ... speed control operation unit, 7 ... second-order system transfer function filter operation unit, 8 ... first-order system transfer function filter operation unit, 9 ... vector control operation unit, 10 ... phase error estimation operation unit, 11 ... frequency and phase estimation operation unit, 12 ... coordinate conversion unit, 20 ... power conversion device, 20a ... control unit, 20b ... digital operator of power conversion device, 26 ... switching speed of low speed area / high speed area, 27 ... attenuation ratio set for low speed area / high speed area, 28 ... personal computer, 29 ... tablet computer, 30 ... smart phone, 31 ... IOT controller, i d * ...d-axis current command value, i q * ...q-axis current command value, ω dc ...Speed ​​estimation value, ω n ...mechanical angular velocity, ω r ...speed of magnet motor 1, v dc * 、v dc ** 、v dc ** 、v dc *** 、v dc **** 、v dc ***** ...d-axis voltage command value, v qc * 、v qc ** 、v qc *** 、v qc **** 、v qc ***** ...q-axis voltage command value, P...power value, Pa...effective power value, Δθ c ...The estimated value of the phase error, ζ a , b ...attenuation ratio, T a ...first-order leading time constant.

Claims

1. A power conversion device for driving a magnet motor, characterized in that: include: a first filter unit having a first-order system transfer function filter that changes in response to a pulsation component of the magnet motor, and calculating a second speed estimated value based on a speed command value and a first speed estimated value; A speed control unit that calculates a first torque current command value based on the speed command value and a second speed estimated value; and The second filter unit has a second-order system transfer function filter that changes in response to the pulsation component, and calculates a second torque current command value based on the first torque current command value. Here, the power supplied to the magnet motor is controlled based on the second torque current command value.

2. The power conversion device according to claim 1, characterized in that: The first filter unit has a parameter related to the speed command value. A calculation including the parameters is performed based on the first estimated speed value to obtain a second estimated speed value.

3. The power conversion device according to claim 1, wherein: The second filter unit has a control mode for suppressing speed pulsation and a control mode for suppressing torque pulsation.

4. The power conversion device according to claim 1, wherein: The second filter unit includes a first second-order system transfer function filter and a second second-order system transfer function filter. The filter is switched to either the first second-order system transfer function filter or the second second-order system transfer function filter based on the speed command value.

5. The power conversion device according to claim 1, wherein: The second filter unit switches to a control mode that suppresses motor speed pulsation when the magnet motor is in a low speed region. When the magnet motor is in a high-speed region, the control mode is switched to a control mode for suppressing motor torque pulsation.

6. The power conversion device according to claim 3, characterized in that: The second filter unit switches to either a control mode for suppressing speed pulsation or a control mode for suppressing torque pulsation, depending on the magnitude of the power calculated value calculated based on the voltage command value and the current detection value.

7. The power conversion device according to claim 6, characterized in that: The second filter unit switches to a control mode that suppresses motor speed pulsation when the magnet motor is in a low power region. When the magnet motor is in a high power region, the control mode is switched to a control mode for suppressing motor torque pulsation.

8. The power conversion device according to claim 1, wherein: Feedback the control quantity including voltage command value, current detection value, phase error, first speed estimation value or second speed estimation value to the upper device for analysis. Modify the parameters of the first-order system transfer function filter or the second-order system transfer function filter.

9. The power conversion device according to claim 1, wherein: A speed value for switching the control mode between the low speed region and the high speed region of the magnet motor, a power value for switching the control mode between the low power region and the high power region of the magnet motor, or a parameter of a first-order system transfer function filter is externally set or changed.

10. The power conversion device according to claim 1, wherein: The first filtering section modifies a parameter of a first-order system transfer function filter in response to the speed command value or the power value.

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