JP4625116B2 - Motor control apparatus, motor control system, motor control module, and refrigeration apparatus - Google Patents

Description

  The present invention relates to a motor control device, a motor control system, a motor control module, and a refrigeration apparatus.

In the position sensorless driving device of a permanent magnet synchronous motor (hereinafter referred to as “motor”), at the beginning of startup, a current of a predetermined amplitude is supplied to the motor while gradually increasing the output frequency of the inverter to rotate the motor by a predetermined rotation. Accelerates to speed (referred to as synchronous operation mode), then estimates the axis error between the motor rotor axis and control system axis from the voltage and current information applied to the motor, and controls the estimated axis error to a predetermined value A method of switching to such a mode (referred to as a sensorless operation mode) is well known.
In this method, when the operation mode is switched at a predetermined rotational speed, the rotor shaft of the motor in the synchronous operation mode and the control system shaft are greatly different due to the motor load torque, or the motor output torque is changed before and after the switching. Since the continuity may not be maintained, a switching shock occurs in which shaft vibration occurs immediately after switching, or the motor current and rotational speed change greatly. In the worst case, a motor overcurrent may occur, and the control system may become unstable.

As a technique for suppressing the switching shock, for example, there is a method described in Patent Document 1. In this prior art, as a method for determining the voltage in the synchronous operation mode, the load torque is estimated based on the relationship that the current flowing through the motor decreases as the load torque increases, and the voltage corresponding to the estimated load torque is applied to the motor. Apply. Thereafter, the motor rotor position is estimated using the induced voltage phase of the motor, and the operation mode is switched.
Patent Document 2 discloses a method of calculating a shaft error between a motor rotor shaft and a control system shaft from a voltage command and a current detection value in a synchronous operation mode, and estimating a load torque at the time of switching.
JP 2004-222382 A JP 2007-33752 A

In the technique of Patent Document 1, a change in load torque is estimated from a change in current flowing in the motor in order to determine a voltage in the synchronous operation mode, but a method for estimating load torque before and after switching is not described. . Further, in order to detect the induced voltage phase of the motor, an additional circuit and a special energization mode of the inverter are required, and the apparatus becomes complicated.
In the technique of Patent Document 2, the load torque before switching can be estimated and the current command after switching can be set according to the load torque, but the adjustment of the axis error between the motor rotor shaft and the control shaft cannot be performed. The axis error at the time of switching remains due to the change of the load situation.

  Therefore, the present invention has been made to solve the above-described problem, and a motor control device, a motor control system, a motor control module, and a motor control device that can reduce a switching shock when switching from the synchronous operation mode to the position sensorless mode. An object is to provide a refrigeration apparatus.

In order to solve the above-mentioned problems, the means of the present invention includes a permanent magnet synchronous motor (1), an inverter (3) that drives the permanent magnet synchronous motor, and a motor current detection that detects a motor current of the permanent magnet synchronous motor. And a control device (6) for performing dq vector control of the permanent magnet synchronous motor using a value, wherein the control device sets the permanent magnet to a rotation angle (θm ^) obtained by integrating the speed command value. Both a synchronous operation mode in which the synchronous motor is driven in synchronization and a position sensorless mode in which the rotation angle (θm) of the permanent magnet synchronous motor is feedback-controlled are provided. During the synchronous operation mode, the permanent magnet synchronous motor An axis error (Δθc) between the rotor axis (dq axis) and the control system axis (dc-dq axis) of the dq vector control is estimated, and the estimated axis error (Δθc) and current command are estimated. (Iqc *, Idc *) phase difference (a current vector phase [theta] s) and fed back controlled so that not one Itasa the axial error that the estimated from the synchronous operation mode after reduction within a predetermined range on the position sensor-less mode A switching device 19 for switching is provided. Thereby, since a sudden change of the rotor position does not occur, there is little switching shock. Note that the symbols and symbols in parentheses are examples.

  According to the present invention, the switching shock when switching from the synchronous operation mode to the position sensorless mode can be reduced.

(First embodiment)
FIG. 1 is a configuration diagram of a motor control system according to first to third embodiments of the present invention.
The motor control system 100 includes a permanent magnet synchronous motor 1, a DC power source 2, an inverter 3 that converts DC power into AC power, a DC voltage detector 4 that detects the voltage of the DC power source 2, and the DC side of the inverter 3. The direct current detector 5 for detecting the current of the current and the control device 6 are provided.

The motor 1 is a permanent magnet synchronous motor.
The DC power source 2 is a converter (rectifier) or a battery that converts AC power supplied from a commercial power source into DC power, and provides power to the DC side of the inverter 3.
The inverter 3 includes six IGBTs (Insulated Gate Bipolar Transistors) and commutation diodes connected to the collectors and emitters of the respective IGBTs.
The control device 6 processes detection signals of the DC voltage detector 4 and the DC current detector 5 using a semiconductor arithmetic element such as a microcomputer or a DSP (digital signal processor). Further, the control device 6 outputs a PWM control signal for performing on / off control of the IGBT that is a semiconductor power element constituting the inverter 3 based on the speed command ωi.

FIG. 2 is a functional block configuration diagram of the control device 6 (6a) of FIG. 1 according to the first embodiment of the present invention, and each function is realized by a CPU (Central Processing Unit) that is a computer and a program.
The control device 6a controls the inverter by generating a PWM control signal based on the speed command ωi by dq coordinate system vector control. The control device 6a includes a dq vector control unit 60, a PLL controller 7, a phase calculator 8, a current command calculator 9, a speed controller 10, a d-axis current command generator 11, and an axis error calculator. 14, an adder 18, and switching devices 19 a, 19 b and 19 c. The dq vector control unit 60 includes a voltage command controller 12a, a two-axis three-phase converter 13, a three-phase two-axis converter 15, a current reproduction calculator 16, and a PWM controller 17, and includes a current command value. A PWM control signal is calculated using (dc-axis current command value Idc ^* , qc-axis current command value Iqc ^* ) and phase θdc of the control axis.

The current reproduction calculator 16 uses the bus current Ish output from the DC current detector 5 (FIG. 1) and the three-phase voltage command values Vu ^* , Vv ^* , Vw ^* to generate three-phase motor currents Iu, Iv, Iw. To reproduce.
The three-phase two-axis converter 15 calculates the dc-axis current detection value Idc and the qc-axis current detection value Iqc based on the reproduced three-phase motor currents Iu, Iv, Iw and the estimated control axis phase θdc. Calculate based on the following equation. The dc-qc axis is defined as the control system axis, the dq axis is defined as the rotor axis of the motor 1, and the axis error between the dc-qc axis and the dq axis is defined as Δθc (FIG. 3). reference).

The voltage command controller 12a includes a dc-axis current command value Idc ^* , a qc-axis current command value Iqc ^* , a dc-axis current detection value Idc, a qc-axis current detection value Iqc, and a speed command value ω1 ^*. Using the motor constant setting values (r ^* , Ld ^* , Lq ^* , Ke ^* ), the dc-axis voltage command value Vdc ^* and the qc-axis voltage command value Vqc ^* are calculated.

FIG. 4 is a detailed functional block configuration diagram of the voltage command controller 12a (FIG. 2). The voltage command controller 12a includes adders 24 and 25, current controllers 21 and 22, and a vector calculator 23, and a deviation between the dc-axis current command value Idc ^* and the dc-axis current detection value Idc and the qc-axis The second dc-axis current command value Idc ^** and the second qc-axis current command value Iqc ^** are calculated from the deviation between the current command value Iqc ^* and the qc-axis current detection value Iqc.
That is, the adder 24 calculates the deviation between the dc-axis current command value Idc ^* and the dc-axis current detection value Idc, and the adder 25 calculates the deviation between the qc-axis current command value Iqc ^* and the qc-axis current detection value Iqc. The current controller 21 and the current controller 22 perform proportional-integral control (PI control) on the respective deviations, and the second dc-axis current command value Idc ^** and the second qc-axis current command value Iqc. ^** is calculated.

２軸／３相変換器１３は、ｄｃ軸電圧指令値Ｖｄｃ^＊、及びｑｃ軸電圧指令値Ｖｑｃ^＊と、位相演算器８が出力した制御系軸の位相θｄｃとに基づいて、（３）式よりモータ１の三相電圧指令値Ｖｕ^＊、Ｖｖ^＊、Ｖｗ^＊を出力する。

The vector calculator 23 uses the second dc-axis current command value Idc ^** , the second qc-axis current command value Iqc ^** , the rotational speed command value ω1 ^* , and the motor constant setting value (2 ) Calculate the dc-axis voltage command value Vdc ^* and the qc-axis voltage command value Vqc ^* . In equation (2), r ^* is the motor winding resistance setting value of the control system, Ld ^* is the motor d-axis inductance setting value, Lq ^* is the motor q-axis inductance setting value, and Ke ^* is the motor induced voltage of the control system. It is a constant set value, and ω1 ^* is a rotation speed command value.

Based on the dc-axis voltage command value Vdc ^* , the qc-axis voltage command value Vqc ^*, and the phase θdc of the control system axis output from the phase calculator 8, the 2-axis / 3-phase converter 13 The three-phase voltage command values Vu ^* , Vv ^* , Vw ^* of the motor 1 are output.

Next, a speed and phase estimation method for realizing position sensorless control will be described.
The axis error calculator 14 calculates the axis using the equation (4) from the dc axis voltage command value Vdc ^* , the qc axis voltage command value Vqc ^* , the dc axis current value Idc, the qc axis current value Iqc, and the motor constant setting value. The error Δθc is calculated.

The PLL controller 7 uses the PI controller to process the deviation between the axis error Δθc output from the axis error calculator 14 and the axis error command value Δθc ^* (usually set to near 0) to estimate the motor rotation speed. The value ωm ^ is output. Here, the PI controller converts the estimated axis error Δθc between the rotor axis (dq axis) of the motor 1 and the control system axis (dc-qc axis) to an axis error command value Δθc ^* (usually near 0). It is controlled to match. The phase calculator 8 integrates the estimated motor rotation speed ωm ^ to calculate the phase θdc of the control system axis.
The above is the basic operation of the position sensorless mode in the control device of the present embodiment.

  However, since the induced voltage of the motor 1 is small when the motor 1 starts up and rotates at a low speed, the control may become unstable due to the error of the result calculated from the equation (4). Therefore, the activation sequence shown in FIG. 5 is adopted.

FIG. 5 is a waveform diagram showing a current command value and a rotational speed command value at the time of starting the motor, and shows a transition of the conventional operation mode when starting the motor 1. The operation mode includes a positioning mode in which the rotor is fixed at a predetermined rotational position by gradually increasing a dc axis current command value Idc ^* flowing through a predetermined motor winding, and a predetermined dc axis current command value Idc ^* . A synchronous operation mode for controlling the applied voltage applied to the motor 1 according to the rotational speed command value ω1 ^*, and a position sensorless mode (feedback operation) for adjusting the current command value and the inverter frequency so that the axis error Δθc becomes a predetermined value. Mode). As will be described later, in the synchronous operation mode of the present embodiment, the qc-axis current command value Iqc ^* is not set to 0, and both the dc-axis current command value Idc ^* and the qc-axis current command value Iqc ^* are controlled. .

In these operation modes, the switching devices 19a, 19b, 19c change any one of the dc axis current command value Idc ^* , the qc axis current command value Iqc ^* , and the input frequency of the phase calculator 8, or By switching the switching devices 19a, 19b, 19c in the control device 6, the operation mode is changed to another operation mode.
In both the positioning mode (time t0 to t1) and the synchronous operation mode (time t1 to t2), the switches 19a, 19b and 19c (FIG. 2) are set to the B side. That is, the speed command ωi (rotational speed command value ω1 ^* ) is directly input to the phase calculator 8 to calculate the control system phase θdc. The dc-axis current command value Idc ^* and the qc-axis current command value Iqc ^* from the current command calculator 9 are supplied to the voltage command controller 12a as they are to calculate the voltage command. Further, the rotational speed command value ω1 ^* is set to zero in the positioning mode and gradually increases in the synchronous operation mode.

At time t2 when the rotational speed of the motor 1 at which position sensorless control is possible is reached, the switches 19a, 19b, 19c are set to the A side, and the operation mode shifts to the position sensorless mode. Thereby, the speed controller 10 adjusts the qc-axis current command value (Iqc ^* ) so that the difference between the motor rotation speed ωm ^* estimated by the PLL controller 7 and the rotation speed command value ω1 ^* becomes zero. As a result, the difference between the axis error Δθc and the axis error command value Δθc ^* (usually near 0) becomes zero.

In other words, the qc-axis current command value Iqc ^* in the position sensorless mode is a value corresponding to the sum of the acceleration torque component Iqca and the load torque component IqcL, and the rotational speed ωm of the motor 1 is accelerated. Thereafter, when the acceleration is completed up to the target speed ω2 and becomes a constant speed, the qc-axis current command value Iqc ^* becomes constant at a value IqcL corresponding to the load torque. At the same time, the dc-axis current command value (Idc ^* ) is given from the d-axis current command generator 11 so that the motor current is minimized (usually near 0). Further, in order to suppress current fluctuation at the time of switching, the dc-axis current command value Idc ^* is gradually changed.

FIG. 6 shows the motor rotor shaft and control system at the time (immediately before) switching from the synchronous operation mode of the conventional method (current command vector phase fixing method) shown in FIG. 5 to the position sensorless control under the conditions of light load and heavy load. It is a vector diagram which shows an axis | shaft and the axial direction component of an electric current. FIG. 6A shows a light load state, and FIG. 6B shows a heavy load state.
In the light load of FIG. 6A, the d-axis current Id is large and the q-axis current Iq is small, whereas in the heavy load of FIG. 6B, the d-axis current Id is small and the q-axis current Iq flows largely.
Comparing the axial error Δθc between FIG. 6A and FIG. 6B, it can be seen that the axial error fluctuates greatly as the starting load increases. In particular, when switching to the position sensorless mode in a heavy load state, a control loop that causes the axis error Δθc to become a predetermined value (usually near 0) works, so the rotor can accelerate rapidly and a switching shock can occur. High nature.

Therefore, FIG. 7 shows the axial components of the motor rotor shaft, the control system shaft, and the current at the time (immediately before) switching from the synchronous operation mode of the present embodiment to the position sensorless control under the same light load and heavy load conditions. FIG. FIG. 7A shows a light load state, and FIG. 7B shows a heavy load state. In the heavy load state (FIG. 7B), the q-axis current command value Iqc ^* is flowed more and the dc-axis current command value Idc ^* is flowed less, so that the d-axis direction and the dc-axis direction coincide with each other. The direction and the qc axis direction can be matched. When the current vector phase θs of the qc-axis current command value Iqc ^* and the dc-axis current command value Idc ^* is adjusted and the shaft error Δθc is reduced and the mode is switched to the position sensorless mode, the rotor position does not suddenly change. There is little switching shock.

Hereinafter, a method for reducing the switching shock from the synchronous operation mode of the present invention to the position sensorless mode will be described.
In the block diagram of FIG. 8, the current command calculator 9 includes a current phase controller 31, a phase generator 36, a switcher 20, a cosine calculator 32, a sine calculator 33, and multipliers 34 and 35. The axis error Δθc is an input signal, and the qc-axis current command value Iqc ^* and the dc-axis current command value Iqd ^* are output signals.

ここで、Ｉｓｙｎｃは同期運転中の電流指令の振幅設定値である。 The current vector phase θs is adjusted using the axis error calculation value Δθc in the synchronous operation mode, and the dc-axis current command value Idc ^* and the qc-axis current command value Iqc ^* are calculated from the equation (5). is there. Here, the axis error calculation value Δθc is obtained from equation (4). The current phase controller 31 processes the axis error calculation value Δθc using a proportional integration (PI) controller or an integration controller, and outputs a current vector phase θs.

Here, Isync is the amplitude setting value of the current command during the synchronous operation.

However, when the rotation speed ωm of the motor 1 is low, the calculation error of the axis error Δθc (Equation (4)) is large, and therefore the control of the current command calculator 9 (FIG. 8) is controlled so that the rotation speed ωm exceeds a predetermined value. To do later. Note that the predetermined value of the rotational speed ωm is smaller than the switching frequency in order to prevent the switching shock by performing earlier than the switching point when switching from the synchronous operation mode to the position sensorless mode.
In addition, in order to suppress the influence of the pulsation component of the motor load torque and the current detection error, the shaft error calculation value Δθc is subjected to a low-pass filter or moving average processing, or the setting response of the current phase controller 31 is reduced. What is necessary is just to add a countermeasure.

The phase generator 36 gradually changes the current vector phase θs from 0 to a predetermined value (for example, 45 °). As a result, the adjustment time of the current vector phase θs when the load condition changes is shortened. The predetermined value may be approximately half of the current vector phase θs corresponding to the maximum starting load. The switch 20 is switched after the current vector phase θs reaches a predetermined value θsa (see FIG. 9).
Furthermore, since the qc-axis current command value Iqc ^* at the final point of the synchronous operation mode substantially corresponds to the load torque at the time of start-up, the qc-axis current command value is set to the initial value and the output initial value of the integral controller of the speed controller 10. If the value Iqc ^* is substituted, the motor current fluctuation before and after switching is reduced.

9 to 11 are simulation waveform diagrams at the time of starting the motor according to the present embodiment, FIG. 9 is a result of light load, FIG. 10 is a result of medium load, and FIG. 11 is a result of heavy load. . In each figure, the horizontal axis represents time [seconds], and the vertical axis represents motor current | I | [A], dc-axis current command value Idc ^* [A], qc-axis current command value Iqc ^* [A], and current vector. The phase θs, the axis error estimated value Δθc [°], and the rotor phase angle θm [°].

In FIG. 9, in the synchronous operation mode (time axis 1 s to 3 s), the current command calculator 9 (FIG. 8) is set to the B side in 1 second to 2.5 seconds, and the current vector phase θs is Increases linearly. As a result, the dc-axis current command value Idc ^* proportional to cos (θs) slightly decreases from about 30A to about 25A, whereas the qc-axis current command value Iqc ^* proportional to sin (θs) decreases from 0A to about 15A. Greatly increases substantially linearly.

Further, in the period of 2.5 seconds to 3 seconds, in the current command calculator 9, the switch 20 is set to the A side, and the current vector phase θs is adjusted. As a result, at the time of switching to the position sensorless mode, the current vector phase θs is adjusted according to the load, and the estimated axis error is almost zero. In addition, it was confirmed that the qc-axis current command value Iqc ^* before and after switching was small and smooth switching was realized. That is, the estimation of the motor load at start-up was realized at the same time.
Further, as the axis error Δθc becomes almost zero, the current vector phase θs also approaches 0, the qc-axis current command value Iqc ^* proportional to sin (θs) approaches 0A, and the dc-axis current command proportional to cos (θs). The value Idc ^* is approaching about 30A.

In the position sensorless mode for a period of 3 seconds or longer, the qc-axis current command value Iqc ^* flows according to the load, and the dc-axis current command value Idc ^* is set to zero. That is, the qc-axis current command value Iqc ^* is automatically adjusted to a large value in the order of FIG. 9 (light load), FIG. 10 (medium load), and FIG. 11 (heavy load), and in this order, the motor current | I | Will increase. Further, the command value in the synchronous operation mode is gradually changed to the command value in the position sensorless mode. Thereby, since the phase difference between the voltage and current applied to the motor 1 is reduced, the power factor of the motor 1 is improved. Further, the jump component of the motor current immediately after switching to the position sensorless mode is within 20% of the motor rated current.

Further, comparing FIG. 9 (light load), FIG. 10 (medium load), and FIG. 11 (heavy load), the amount of change in the qc-axis current command value Iqc ^* during the control ON period is greatly different in each figure.
That is, the period from 1 second to 2.5 seconds increases linearly to about 14A, while in the position sensorless mode after the switching time (3 seconds), the light load (FIG. 9) is about 1A. The amount of change is 13A, the amount of change is 6A because the medium load (FIG. 10) is about 8A, and the amount of change is 0A because the heavy load (FIG. 11) is about 14A. In a heavy load, the qc-axis current command value Iqc ^* increases after slightly decreasing in a period of 2.5 s to 3 s.

As described above, according to the present embodiment, the current vector phase θs is automatically adjusted according to the magnitude of the motor starting load, and the rotor axis is adjusted to coincide with the control system axis. Further, since the adjusted qc-axis current command value Iqc ^* substantially matches the current value corresponding to the load torque, torque fluctuation is small before and after switching when switching from the synchronous operation mode to the position sensorless mode.

  In the present embodiment, the bus current Ish is detected using a shunt resistor, and the three-phase motor currents Iu, Iv, Iw are calculated from the bus current Ish using the current reproduction calculator 16 (FIG. 2). Actually, the bus current may be detected using not only a shunt resistor but also a Hall element. Further, three-phase motor currents Iu, Iv, and Iw may be detected instead of the bus current.

ここで、ΔＶｄｃ、ΔＶｑｃは電流制御器３９，４０の出力である。
また、起動シーケンスや同期運転モード中の電流ベクトル位相調整と電流指令の演算も、第１実施形態と同様に行う。 (Second Embodiment)
FIG. 12 is a detailed functional block configuration diagram of the voltage command controller 12 (12b) of the motor control device according to the second embodiment of the present invention. The difference from FIG. 4 is that the voltage command value calculation is changed to the sum of the output of the vector calculator 42 and the outputs of the current controllers 39 and 40 as shown in the equation (6). The current reproduction calculation and the phase estimation process are the same as in the first embodiment.

Here, ΔVdc and ΔVqc are outputs of the current controllers 39 and 40.
Further, the current vector phase adjustment and the current command calculation during the start-up sequence and the synchronous operation mode are performed in the same manner as in the first embodiment.

(Third embodiment)
The components of the motor control device of the third embodiment of the present invention are the same as those shown in FIG. 1, but the vector control method inside the control device 6 is different.

(Overall configuration of control)
FIG. 13 is a functional block configuration diagram inside the control device 6 (6b) according to the third embodiment of the present invention. The same reference numerals as those in FIG. 2 perform the same operation.
The difference from FIG. 2 is that the qc-axis current command value Iqc ^{* in the} position sensorless mode is calculated from the low-pass filter 52, and the PLL controller 7 (FIG. 2) that performs the process of estimating the rotational speed ωm of the motor 1 That is, a speed error calculator 50 that calculates the speed error and an adder 51 that calculates the sum of the speed error and the speed command are changed.
That is, the speed error calculator 50 proportionally calculates the axis error Δθc calculated by the axis error calculator 14 to calculate the speed error Δωm, the adder 51 adds the speed command ωi and the speed error Δωm, and the switcher The addition result is input to the phase calculator 8 through 19c.

電流再現と軸誤差演算、及び位相演算処理は、第１実施形態と同様である。起動シーケンスや同期運転モード中の電流ベクトル位相調整と電流指令の演算も、第１実施形態と同様に行う。 Thereby, the calculation process in the voltage command controller 12a is simplified like (7) Formula.

The current reproduction, axis error calculation, and phase calculation processing are the same as in the first embodiment. The current vector phase adjustment and current command calculation during the start-up sequence and the synchronous operation mode are performed in the same manner as in the first embodiment.

(Fourth embodiment)
FIG. 14 is an external view of a module 200 for a motor drive device according to an embodiment of the present invention, and shows one form of a final product.
The module 200 is a module for a motor control device in which the semiconductor element 202 is mounted on the control unit substrate 201. The control unit substrate 201 includes the DC current detector 5, the DC voltage detector 4, and the control shown in FIG. The device 6 is directly mounted, and the inverter 3 is mounted as a semiconductor element 202 made into one chip. Miniaturization is achieved by modularization, and the device cost can be reduced. The module means “standardized structural unit” and is composed of separable hardware / software components. Moreover, although it is preferable to comprise on the same board | substrate on manufacture, it is not limited to the same board | substrate. From this, it may be configured on a plurality of circuit boards built in the same housing.

  According to the present embodiment, it is possible to automatically adjust the motor rotor shaft, the control shaft, and the initial value of the current command according to the load torque by adjusting the current phase in the synchronous operation mode at the time of startup. Sudden fluctuations in current and torque are small, switching shock is greatly reduced, and more stable start-up operation can be realized.

(Fifth embodiment)
FIG. 15 is a configuration diagram of a refrigeration apparatus such as an air conditioner or a refrigerator using the motor control system 100 (FIG. 1) according to the embodiment of the present invention.
The refrigeration apparatus 300 is an apparatus that harmonizes temperatures, and includes heat exchangers 301 and 302, fans 303 and 304, a compressor 305, a pipe 306, and a motor driving device 307. The motor driving device 307 converts AC power into DC and provides it to the motor driving inverter 3 to drive the motor 1 arranged inside the compressor 305.
By using the motor driving device of the first to third embodiments and the motor driving module of the fourth embodiment, the synchronous operation mode at the start of the compressor and the fan motor can be performed under the condition that the rotation angle sensor of the motor 1 is not present. By automatically adjusting the rotor axis and control system axis of the motor 1 and the initial value of the current command according to the load torque by adjusting the current phase, there is little sudden fluctuation of the motor current and torque at the time of switching, and the switching shock is greatly increased Can be reduced and startup performance can be improved. In particular, when the internal pressure of the compressor remains or the refrigerant temperature is low, even if the load conditions at the start of the motor change drastically, it can be started smoothly, improving the reliability of the device and the comfort during use. .

It is a block diagram of the motor control system which is one Embodiment of this invention. It is a functional block block diagram of the control apparatus which is 1st Embodiment of this invention. It is a figure for demonstrating the control system estimation axis | shaft and rotor axis | shaft of the motor control system which are 1st Embodiment of this invention. It is a block diagram of the voltage command controller of the motor control apparatus which is 1st Embodiment of this invention. It is a wave form diagram of a current command value and a rotation speed command value at the time of motor starting. It is a current vector diagram of the conventional method demonstrated with the rotor axis | shaft of a motor, and a control system axis | shaft. It is an electric current vector figure of a 1st embodiment explained with a rotor axis of a motor, and a control system axis. It is a block diagram of the electric current command calculator of the motor control apparatus which is 1st Embodiment. It is a simulation waveform figure at the time of motor starting in light load conditions. It is a simulation waveform figure at the time of motor starting in a medium load condition. It is a simulation waveform figure at the time of motor starting in heavy load conditions. It is a detailed functional block block diagram of the voltage command controller of the motor control apparatus which is 2nd Embodiment of this invention. It is a functional block block diagram of the motor control apparatus which is 3rd Embodiment of this invention. It is an external view of the module used for the motor control apparatus which is 4th Embodiment of this invention. It is a block diagram of the freezing apparatus which is 5 embodiment of this invention.

Explanation of symbols

1 Motor (permanent magnet synchronous motor, compressor motor)
2 DC power supply 3 Inverter 4 DC voltage detector 5 DC current detector 6, 6a, 6b Control device (control means)
7 PLL controller 8 Phase calculator 9 Current command calculator 10 Speed controller 11 d-axis current command generator 12 Voltage command controller 13 2-axis 3-phase converter 14 Axis error calculator 15 3-phase 2-axis converter 16 Current Reproduction calculator 17 PWM controller 18, 24, 25, 37, 38, 43, 44, 51 Adder 19a, 19b, 19c, 20 Switcher 21, 22, 39, 40 Current controller 23, 42 Vector calculator 31 Current phase controller 32 Cosine calculator 33 Sine calculator 34, 35 Multiplier 36 Phase generator 50 Speed error calculator 52 Low pass filter 60 dq vector controller 100 Motor control system 200 Module 201 Controller board 202 Semiconductor element (power module) )
300 Refrigeration equipment 301, 302 Heat exchanger 303, 304 Fan 305 Compressor 306 Piping 307 Motor drive device

Claims (15)

In the motor control device including a dq vector control unit that controls the rotation speed of the permanent magnet synchronous motor via the inverter so that the rotation speed matches the speed command value,
Both a synchronous operation mode in which the permanent magnet synchronous motor is driven in synchronization with a rotation angle obtained by integrating the speed command value, and a position sensorless mode in which the rotation angle of the permanent magnet synchronous motor is feedback-controlled,
During the synchronous operation mode, causes the estimates the axis error between the control system axis of the dq vector control unit and the rotor shaft of the permanent magnet synchronous motor, the phase difference of the estimated axis error and the current command value one Itasa A motor control device comprising: a switching device that performs feedback control so as to switch from the synchronous operation mode to the position sensorless mode after the estimated axis error is reduced within a predetermined range .   The axis error is calculated using a motor current detection value of the permanent magnet synchronous motor and an applied voltage value applied to the permanent magnet synchronous motor or a voltage command value of the inverter and a motor constant. The motor control device according to claim 1. 2. The motor control device according to claim 1, wherein a fluctuation angle of the axis error before and after switching from the synchronous operation mode to the position sensorless mode is reduced within 20 °. 2. The feedback control is performed after the current vector phase of the qc-axis current command value and the dc-axis current command value is gradually changed from 0 ° to a predetermined value angle in the synchronous operation mode. The motor control device described in 1. Before switching from the synchronous operation mode to the position sensor-less mode, when the motor rotational speed is a predetermined value or more, by using a proportional integrator or integrator, according to claim 1, characterized in that said feedback control Motor control device.   The position sensorless mode estimates the axis error between the rotor shaft and the control system shaft of the permanent magnet synchronous motor, adjusts the motor rotation speed command value so that the shaft error becomes a predetermined value, The motor control device according to claim 1, wherein the motor control device controls a value or a voltage command value of an applied voltage applied to the permanent magnet synchronous motor. Before switching from the synchronous operation mode to the position sensorless mode, the initial value of the current controller in the position sensorless mode is set by using the feedback-controlled qc-axis current command value and the dc-axis current command value. The motor control device according to claim 5 or 6 , wherein The motor control device according to claim 7 , wherein control is performed so that a fluctuation range of the qc-axis current before and after switching from the synchronous operation mode to the position sensorless mode is within 20% of a motor rated current. The dc-axis current command value is controlled to gradually change from the command value in the synchronous operation mode to the command value in the position sensorless mode after switching from the synchronous operation mode to the position sensorless mode.
The motor control device according to claim 7 , wherein a phase difference between a motor voltage applied to the permanent magnet synchronous motor and a motor current flowing through the permanent magnet synchronous motor is reduced. The motor control according to claim 7 or 8, wherein a motor current flowing through the permanent magnet synchronous motor after switching from the synchronous operation mode to the position sensorless mode is automatically adjusted according to a motor load. apparatus. The jump component of the motor current flowing in the permanent magnet synchronous motor immediately after switching from the synchronous operation mode to the position sensorless mode is
The motor control device according to claim 7 or claim 8, characterized in said feedback controlled are possible to be within 20% of the motor rated current. The rotational speed of the rotor of the permanent magnet synchronous motor before and after switching from the synchronous operation mode to the position sensorless mode is
Regardless of motor load, the motor control device according to claim 7 or claim 8 weight variation within a short period of time, characterized in that it is the feedback controlled to within 20%. A permanent magnet synchronous motor, an inverter that drives the permanent magnet synchronous motor, and a controller that performs dq vector control of the permanent magnet synchronous motor using a motor current detection value obtained by detecting a motor current of the permanent magnet synchronous motor. Motor control system
The controller is
Both a synchronous operation mode in which the permanent magnet synchronous motor is driven in synchronization with a rotation angle obtained by integrating the speed command value, and a position sensorless mode in which the rotation angle of the permanent magnet synchronous motor is feedback-controlled,
During the synchronous operation mode, the estimated axis error between the control system axis of the permanent magnet synchronous motor rotor shaft and the dq vector control, Ru causes a phase difference of the estimated axis error and the current command value one Itasa A motor control system comprising: a switching device that performs feedback control as described above and switches from the synchronous operation mode to the position sensorless mode after the estimated axis error is reduced within a predetermined range . In the motor control module including a dq vector control unit that controls the rotation speed of the permanent magnet synchronous motor via an inverter so that the rotation speed matches the speed command value.
Both a synchronous operation mode in which the permanent magnet synchronous motor is driven in synchronization with a rotation angle obtained by integrating the speed command value, and a position sensorless mode in which the rotation angle of the permanent magnet synchronous motor is feedback-controlled,
During the synchronous operation mode, causes the estimates the axis error between the control system axis of the dq vector control unit and the rotor shaft of the permanent magnet synchronous motor, the phase difference of the estimated axis error and the current command value one Itasa A motor control module comprising a switch for performing feedback control so as to switch from the synchronous operation mode to the position sensorless mode after the estimated axis error is reduced within a predetermined range . A permanent magnet synchronous motor, an inverter that drives the permanent magnet synchronous motor, and a controller that performs dq vector control of the permanent magnet synchronous motor using a motor current detection value obtained by detecting a motor current of the permanent magnet synchronous motor. In refrigeration equipment
The controller is
Both a synchronous operation mode in which the permanent magnet synchronous motor is driven in synchronization with a rotation angle obtained by integrating the speed command value, and a position sensorless mode in which the rotation angle of the permanent magnet synchronous motor is feedback-controlled,
During the synchronous operation mode, the estimated axis error between the control system axis of the permanent magnet synchronous motor rotor shaft and the dq vector control, Ru causes a phase difference of the estimated axis error and the current command value one Itasa In this way, the feedback control is performed, and after the estimated axis error is reduced within a predetermined range, the synchronous operation mode is switched to the position sensorless mode.

Images