JP5178350B2 - Motor drive apparatus and refrigeration apparatus using the same - Google Patents

Description

  The present invention relates to a permanent magnet synchronous motor control device, a motor driving module, and a refrigeration apparatus.

  In order to realize high control performance, a permanent magnet synchronous motor (hereinafter referred to as “motor”) drive device is known as a general control method using an inverter circuit and a digital controller. . However, since the motor constant is used for vector control, it is necessary to measure the motor constant and set the control constant in advance. In addition, if there is a constant variation due to a constant variation at the time of manufacturing the motor and an operation state, the preset control constant may be shifted from the motor constant, and the control performance may be deteriorated.

  Patent Document 1 discloses a technique for automatically measuring motor constants (winding resistance and inductance) in a motor stationary state using a motor driving inverter circuit and a controller.

  Patent Document 2 discloses a method for obtaining a motor constant from a detected current value of a vector control system, a current command value, and a motor constant initial setting value in a motor operation state.

Further, Non-Patent Document 1 proposes a virtual inductance control method for a position sensorless high-efficiency control method for a permanent magnet synchronous motor. By using a conventional motor dq axis inductance L _d and L _q as one motor virtual inductance value L ^* , a highly efficient operation can be realized with a simple control method.

JP 2003-164188 A JP 2007-49843 A “Torque Maximum Control Method Suitable for Position Sensorless Control of Permanent Magnet Synchronous Motor”

  In the technique described in Patent Document 1, a high-accuracy current sensor and an A / D converter are required, and the measurement accuracy may be deteriorated due to an offset or detection noise between the current sensor and the A / D converter. Moreover, since the constant measured in the stationary state of the motor may not match the actual operation state, there is a concern about deterioration of the control characteristics.

  Patent Document 2 proposes a method for calculating a motor constant using a current detection value, a voltage command value, and a motor constant initial setting value of a vector control system while the motor is in operation. There are still practical problems such as the influence of position detection errors and the method of setting control constants. Therefore, an object of the present invention is to realize high control performance by high-precision motor constant identification without using complicated calculation.

  The motor control device of the present invention includes a permanent magnet synchronous motor, an inverter circuit that is connected to a DC power source and drives the permanent magnet synchronous motor, and a motor current detection that detects the motor current from the output current of the inverter circuit or the bus current on the DC side. And a motor drive apparatus comprising a control means for controlling the rotational speed of the permanent magnet synchronous motor using a motor current detection value, wherein the control means includes a constant identification calculation unit for adjusting a motor constant set value and a control constant; A voltage command control unit that calculates a voltage command value to be applied to the permanent magnet synchronous motor so that the motor current detection value matches the motor current command value, and the voltage command control unit has a motor current detection value equal to the motor current command value. A current control unit that outputs a compensation value so as to match the motor constant, and the constant identification calculation unit uses the compensation value to calculate an error in the motor constant setting value. And, wherein the identifying motor constants and control constants.

  ADVANTAGE OF THE INVENTION According to this invention, the motor control apparatus which implement | achieves high control performance can be provided, without performing the prior measurement and setting operation | work of a motor constant.

  The features of the present invention are listed below.

  The motor control device of the present invention includes a permanent magnet synchronous motor, an inverter circuit connected to a DC power source and driving the permanent magnet synchronous motor, and a motor current that detects a motor current from an output current of the inverter circuit or a bus current on the DC side. In the motor drive device including the detection means and the control means for controlling the rotation speed of the permanent magnet synchronous motor using the detected motor current value, the control means includes a constant identification calculation unit for adjusting the motor constant set value and the control constant; A voltage command control unit that calculates a voltage command value to be applied to the permanent magnet synchronous motor so that the motor current detection value matches the motor current command value, and the voltage command control unit has a motor current detection value equal to the motor current command value. A current control unit that outputs a compensation value so that it matches the current value, and the constant identification calculation unit calculates the error of the motor constant setting value using the compensation value , And identifying motor constants and control constants.

  In addition, the voltage command control unit obtains a second current command value calculated from a deviation between the motor current detection value and the motor current command value, a motor rotation speed command value or a motor rotation speed detection value, and a motor constant setting value. The voltage command value is calculated from the motor voltage equation, and the constant identification calculation unit identifies the motor constant and the control constant from the deviation between the second current command value and the motor current command value or the detected motor current value. It is characterized by that.

  Further, the voltage command control unit uses the motor current command value or the motor current detection value, the motor rotation speed command value or the motor rotation speed detection value, and the motor constant setting value to calculate a voltage command calculation calculated from the motor voltage equation. The voltage command value is calculated by adding the value and the voltage command compensation value calculated from the deviation between the motor current command value and the motor current detection value. The motor constant and the control constant are identified.

  More specifically, the motor rotation speed command value is set to 0, the d-axis current command value is set to a predetermined value, the q-axis current command value is set to 0, and the second d-axis value is set to a predetermined time before the motor is started. The error of the motor winding resistance setting value is calculated from the deviation between the current command value and the d-axis current command value or the d-axis current detection value or the d-axis voltage command compensation value, and the motor winding resistance setting value is obtained. By adding, the motor winding resistance and the control constant are identified.

  In addition, the d-axis current command value is set to 0 at a predetermined time while the motor is rotating, and the d-axis second current command value and the d-axis current command value or the d-axis current detection value The motor induced voltage constant and the control constant are identified by calculating the error of the motor induced voltage constant set value from the deviation of the voltage or the q-axis voltage command compensation value and adding it to the motor induced voltage constant set value. To do.

  Furthermore, the axis error between the control system axis and the motor maximum torque axis is calculated based on the voltage command value, motor current detection value or motor current command value, motor winding resistance setting value, and motor virtual inductance setting value. And a means for controlling the axis error to 0, and in a state where the motor is rotating, the d-axis current command value is set to a predetermined value other than 0 at a predetermined time after completion of identification of the motor induced voltage constant, An error of the motor virtual inductance setting value is calculated from the deviation between the d-axis second current command value and the d-axis current command value or the d-axis current detection value or the q-axis voltage command compensation value, and the motor The motor virtual inductance and the control constant are identified by adding to the virtual inductance set value.

  In addition, in the motor driving device having a position sensor, when the motor is rotating, the d-axis current command value is set to a predetermined value other than 0 at a predetermined time after completion of identification of the motor induced voltage constant. Set, calculate the error of the motor virtual inductance setting value from the deviation between the d-axis second current command value and the d-axis current command value or the d-axis current detection value or the q-axis voltage command compensation value; By adding to the motor d-axis inductance setting value, the motor d-axis inductance and the control constant are identified, and the deviation between the q-axis second current command value and the q-axis current command value or the q-axis current detection value. Alternatively, the motor q-axis inductance and the control constant are identified by calculating the error of the motor q-axis inductance setting value from the d-axis voltage command compensation value and adding it to the motor q-axis inductance setting value. And butterflies.

  Furthermore, the identification of motor constants and control constants is repeated several times, and the identification of motor constants and control constants is characterized by using an integrator or proportional integrator. Is stored in a device such as a semiconductor memory, and is read out and used in accordance with the operation status.

  In addition, when the motor is rotating, if the motor rotation speed command value or the motor rotation speed detection value, the motor current command value or the motor current detection value, or any variation exceeds a predetermined value, the motor induced voltage constant , Motor virtual inductance, motor d-axis inductance, and motor q-axis inductance constants are re-executed, and the motor constant identification results, motor constant rating values, and initial setting values Alternatively, when the deviation from the preset value is greater than or equal to a predetermined value, it is determined that the motor control device has failed.

  As a further feature, the present invention relates to a motor driving module and a refrigeration apparatus, and includes a permanent magnet synchronous motor, an inverter circuit connected to a DC power source and driving the permanent magnet synchronous motor, and an output current of the inverter circuit Alternatively, in a motor drive module comprising: motor current detection means for detecting a motor current from a DC side bus current; and control means for controlling the rotational speed of the permanent magnet synchronous motor using a motor current detection value. The means includes a constant identification calculation unit that adjusts the motor constant setting value and the control constant, and a voltage command control unit that calculates a voltage command value to be applied to the permanent magnet synchronous motor so that the motor current detection value matches the motor current command value. And the voltage command control unit outputs a compensation value so that the motor current detection value matches the motor current command value. Comprising a control unit, constant identifying unit is, calculates the error of the motor constant set value using a compensation value, and identifying motor constants and control constants.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram of a motor drive device according to a first embodiment and a second embodiment of the present invention.

  This motor drive device includes a permanent magnet synchronous motor 1, a DC power source 2, an inverter 3 for converting DC to AC, a DC voltage detector 5, a bus current detector 4 provided on the DC side of the inverter, and a controller. 6.

  The DC power source 2 is a converter (rectifier) or a battery that converts an external AC power source into DC, and provides power to the DC side of the inverter 3. The controller 6 uses a semiconductor arithmetic element such as a microcomputer or a DSP (digital signal processor) to process detection signals from the DC voltage detector 5 and the bus current detector 4 to form a semiconductor constituting the inverter 3. The power element on / off control signal is output.

  FIG. 2 is a functional block configuration diagram of the controller 6 of the motor drive device according to the first and second embodiments of the present invention, and each function is realized by a CPU (computer) and a program.

  The controller 6 calculates a voltage command signal to be applied to the motor by dq vector control and generates an inverter PWM control signal. The controller 6 includes a speed controller 10, a d-axis current command generator 11, a voltage command. A controller 12, a motor constant identifier 13, a two-axis three-phase converter 14, a speed and phase estimator 15, a three-phase two-axis converter 16, a current reproduction calculator 17, a PWM controller 18, And a subtractor 19.

Current reproduction calculator 17, a bus current I _sh is a detection signal outputted from the bus current detector 4, the three-phase voltage command value V _u ^*, V _v ^*, the three-phase motor current using a V _w ^* _Iu , _Iv , and _Iw are reproduced. Based on the reproduced three-phase motor current and the estimated phase information θ _dc , the three-phase two-axis converter 16 converts the dc-axis current detection value I _dc and the qc-axis current detection value I _qc into the following equations: Calculate based on. The dc-qc axis is the estimated axis of the control system, the dq axis is the motor rotor axis, the do-qo axis is the motor maximum torque axis, and the axis error between the do-qo axis and the dc-qc axis is Δθc. (FIG. 3).

In the voltage command controller 12, the dc axis current command value I _dc ^* given from the d axis current command generator 11, the qc axis current command value I _qc ^* given from the speed controller 10, and the dc axis current detection value I _{Using dc} , qc-axis current detection value I _qc , motor rotation speed command value ω ₁ ^* and motor constant setting values (r ^* , L ^** , Ke ^* ), dc-axis voltage command value V _dc ^* , qc The shaft voltage command value V _qc ^* is calculated. The motor constant identifier 13 identifies a motor constant using the vector calculation amount of the voltage command controller 12. Detailed description of the vector calculation method of the voltage command controller 12 and the identification principle of the motor constant identifier 13 will be described later.

  Next, a speed & phase estimation method for realizing position sensorless control will be described.

  FIG. 4 is a detailed functional block configuration diagram of the velocity & phase estimator 15.

  The phase estimator estimates the rotor position by a motor rotor position sensorless control method, and an axis error calculator 20 between the motor maximum torque axis (do-qo axis) and the control system axis (dc-qc axis). And a motor rotation speed estimator 21 and a phase calculator 22.

The axis error calculator 20 calculates an axis error Δθc from the dc axis voltage command value V _dc ^* , qc axis voltage command value V _qc ^* , dc axis current value i _dc , and qc axis current value i _qc using the following equations. To do.

The speed estimator 21 processes the shaft error Δθc output from the shaft error calculator 20 using a PI controller, and outputs an estimated value ωm of the motor rotation speed. Here, the PI controller performs PLL control so as to eliminate the estimated axis error Δθc between the motor maximum torque axis (do-qo axis) and the dc-qc axis of the control system. The phase calculator 22 integrates the estimated motor rotation speed estimated value ωm to calculate the phase θ _{dc of the} control axis.

  The above is the basic operation of vector control and position sensorless control in the motor control device of the present invention.

  Next, a voltage command calculation method and a constant identification principle according to the first embodiment of the present invention will be described.

  FIG. 5 is a detailed functional block configuration diagram of the voltage command controller 12 and the motor constant identifier 13.

The basic operation of the voltage command controller 12 is a d-axis current controller 39 and a q-axis current controller 40, a dc-axis current command value I _dc ^* given from the d-axis current command generator 11, and a speed controller 10. Using the given qc-axis current command value I _qc ^* , dc-axis current detection value I _dc , and qc-axis current detection value I _qc , an intermediate second dc-axis current command value I _dc ^* used for vector calculation ^* And the second qc-axis current command value I _qc ^** are calculated. In the vector computing unit 42, the second dc-axis current command value I _dc ^** , the second qc-axis current command value I _qc ^** , the motor rotation speed command value ω ₁ ^*, and the motor constant set value (r ^* , L ^** , Ke ^* ), the dc-axis voltage command value V _dc ^* and the qc-axis voltage command value V _qc ^* are calculated as shown in equation (3). In the equation (3), r ^* is a control system motor winding resistance setting value, L ^** is a control system motor virtual inductance setting value, Ke ^* is a control system motor induced voltage constant setting value, and ω ₁ ^* Is the motor rotation speed command value. Here, the difference from the general dq axis motor equation is that the motor dq axis inductances L _d and L _q are replaced with one motor virtual inductance L ^* . Finally, based on the dc-axis voltage command value V _dc ^* , the qc-axis voltage command value V _qc ^* and the estimated phase information θ _dc , the motor three-phase voltage command value V _u ^* , V _v ^* and V _w ^* are output.

  Since the set value of the virtual inductance is used in the equations (2) and (3), the motor maximum torque control can be realized by the theoretical analysis described in Non-Patent Document 1.

Such a control system requires motor constant setting values (r ^* , L ^** , Ke ^* ). Naturally, an error between the motor constant setting value of the control system and the motor constant has an influence on the motor control performance (drive efficiency, response speed, stability, etc.). In particular, since the virtual inductance setting value is related to the motor maximum torque control, it greatly affects the motor current and the driving efficiency. Therefore, it is necessary to accurately set the virtual inductance value in the control system.

Next, an automatic identification method for motor constants (motor winding resistance r, motor induced voltage constant set value Ke and motor virtual inductance L ^* ) according to the present invention will be described.

In a steady state, when the motor constant setting values (r ^* , L ^** , Ke ^* ) of the control system match the motor constants, the input of the vector calculator 42 (second dc-axis current command value I _dc ^{* *} And the second qc-axis current command value I _qc ^** ) are the d-axis and q-axis current detection values I _dc and I _qc (or the dc-axis current command value I _dc ^* and the qc-axis current command value I _qc ^* ) Although the values are substantially the same, when the motor constant setting value of the control system deviates from the motor constant, the current deviation appears.

Hereinafter, an identification principle and a realization method of the motor winding resistance r, the motor induced voltage constant set value Ke, and the motor virtual inductance L ^* will be described using the current deviation.

  When the output voltage command of the formula (4) is applied to the motor via the inverter, the relationship between the motor detection current and the voltage command is approximated by the following formula in a steady state.

Here, I _dc and I _qc are motor detection currents, and L ^* , Ke, and r are motor constants.

FIG. 6 shows a current command value at the time of motor rotor positioning operation (from the time (t0) to the time (t1)) performed at the beginning of the motor startup. A d-axis current command waveform 50 indicates a dc-axis current command value, and a q-axis current command waveform 51 indicates a qc-axis current command value. The motor rotor positioning operation is an operation in which the motor rotation speed command value ω ₁ ^* is set to 0 and a motor current is passed as shown in FIG. By this operation, the position of the motor rotor is fixed at a predetermined position.

  Under the above conditions, the voltage command value is the following equation from the equation (3).

  Moreover, the following formula is obtained from the formula (5).

  From the formula (6) and the formula (7), the following formula is obtained.

Since the d-axis current controller 39 is provided, the dc-axis motor current detection value (I _dc ) and the dc-axis current command value (I _dc ^* ) are considered to be substantially equal. Therefore, when Expression (8) is modified, Expression (9) is obtained.

（数９）式より、モータの位置決め動作中に、第２のｄｃ軸電流指令値Ｉ_dc ^**とｄｃ軸電流指令値Ｉ_dc ^*の差から、巻線抵抗の誤差を演算できることがわかった。

From the equation (9), it was found that the winding resistance error can be calculated from the difference between the second dc-axis current command value I _dc ^** and the dc-axis current command value I _dc ^* during the motor positioning operation. .

In a steady state during motor rotation, the motor rotation speed command value (ω ₁ ^* ) and actual value (ω ₁ ), the dc-axis motor current detection value (I _dc ), and the dc-axis current command value (I _dc ^*) ) Is almost equal. Furthermore, when it is assumed that the motor is rotating at a medium or high speed or that the error of the resistance setting value is small, the following equation is established from the equations (3) and (5).

  When the above equation is modified, the following equation (11) is obtained.

Therefore, if the dc-axis current command value I _dc ^* is set to 0 in the steady state during motor rotation, the error of the induced voltage constant can be calculated from the second dc-axis current command I _dc ^** from the equation (11). (ΔKe = Ke−Ke ^* ) is obtained.

Next, after the identification of the induced voltage constant is completed (assuming Ke ^* = Ke), when a predetermined value (= I _dc ^* _{_at} ) is given to the dc-axis current command value I _dc ^* , the equation (11) is obtained. The error of the motor virtual inductance L ^* is obtained by the following equation.

From the above description, the relationship between the motor winding resistance, the induced voltage constant, the error of the virtual inductance, and the current command value deviation (I _dc ^{** −} I _dc ^* ) was found.

  Next, a practical identification method and control system configuration will be described using the detailed functional block configuration diagram of the motor constant identifier 13 shown in FIG.

In the present invention, in order to simplify the arithmetic processing and suppress the influence of sudden fluctuations in the control constant, the current command value deviation (I _dc ^{** −} I _dc ^* ) is processed by an integrator to obtain an error in the control constant. The method of adding to the control constant initial value is adopted.

  The motor constant identifier 13 includes an input switching unit 30, an identification control unit 31, integrators 32a, 32b, and 32c, constant storage units 33a, 33b, and 33c, and adders 34, 35, and 36.

As described above, the winding resistance is identified during the positioning operation before starting the motor. The current command deviation on the dc axis is input to the integrator 32a via the input switch 30 to calculate the motor winding resistance error Δr. At the same time, the motor winding resistance error Δr is output together with the motor winding resistance initial setting value r ^* 0 using the adder 34, and the resistance constant used for the vector calculator 42 is adjusted. At the end of positioning, the output of the integrator 32a is stored in the constant storage 33a, added to the motor winding resistance initial setting value r ^* 0, and the motor winding resistance setting value r ^* is output.

When the motor is at a predetermined speed or more and the load is in a stable state, the induced voltage constant and the virtual inductance are identified according to the following procedure. The predetermined speed here is a minimum speed at which the influence of the motor winding resistance error and the non-linear characteristics of the inverter output (voltage drop or dead time of the semiconductor power element) can be ignored.
(1) Like the current command waveform shown in FIG. 7, the dc-axis current command value (I _dc ^* ) is set to 0 from the time (t2) to the time (t3), and the current command value deviation (I _dc ^{** −} I _dc ^* ) is input to the integrator 32b via the input switch 30 and the motor induced voltage constant error ΔKe is output. Here, the qc-axis current command value (I _qc ^* ) indicates that a current value corresponding to the load torque is output.
(2) The adder 35 adds the error ΔKe of the induced voltage constant to the motor induced voltage constant initial set value ΔKe ^* 0 to adjust the motor induced voltage constant set value Ke ^* used for the vector calculator 42.
(3) After a predetermined time has elapsed (at time (t3)), the output of the integrator 32b is stored in the constant storage unit 33b and added to the motor induced voltage constant initial setting value Ke ^* 0 to obtain the motor induced voltage constant setting value. Output Ke ^* .
(4) Subsequently, from the time (t3) to the time (t4), the dc-axis current command value (I _dc ^* ) is set to a predetermined value I _{dc_at} ^* , and the current command value deviation (I _dc ^** −I _dc ^* ) is input to the integrator 32c via the input switch 30 and the motor virtual inductance error ΔL ^* is output. It should be noted that the dc-axis current command value (I _dc ^* ) should be gradually changed so as not to cause instability of the control system.
(5) The adder 36 adds the motor virtual inductance error ΔL ^* to the initial value L ^** 0 of the motor virtual inductance to adjust the motor virtual inductance set value L ^** used for the vector calculator 42. At the same time, as shown in the equation (14), the control gains of the current controllers 39 and 40 may be adjusted using the adjusted virtual inductance setting value.

(6) After a predetermined time has elapsed (at time (t4)), the dc-axis current command value (I _dc ^* ) is returned to 0, the output of the integrator 32c is stored in the constant storage unit 33c, and the virtual inductance is initially installed. ^Adds L ^** 0 and outputs a virtual inductance set value L ^** .
(7) To further improve the identification accuracy, the identification operations (1) to (6) may be repeated several times.

  Also, if the operating conditions (rotation speed, load, etc.) fluctuate significantly, the motor constant may change due to fluctuations in the motor temperature or magnetic flux. If this occurs, re-identification by the above procedure can avoid a decrease in control performance. Furthermore, if a plurality of identification results in each driving situation are stored in the constant storage units 33a, 33b, and 33c, the stored values can be used from the next time, so constant identification need not be performed.

Note that the dc-axis current command predetermined value (I _{dc_at} ^* ) at the time of virtual inductance identification should be set as small as possible to avoid the effects of inverter overcurrent and motor magnetic saturation. In consideration of the above, in order to ensure the identification accuracy, it may be set in the range of about 1/10 to 1/2 of the rated current of the motor. Further, as described above, the virtual inductance identification should be performed in substantially the same operating state after the induction voltage constant identification is completed.

  However, when performing constant identification as described above, if the control constant is changed suddenly, the control system may become unstable, so the response of the identification integrator must be set sufficiently slower than the control response of the vector control system. There is. If the time constant of the integrator is set to be large, the influence of current ripple and noise can be avoided, so that the identification accuracy can be improved.

  The above is the description of the practical identification method and execution procedure of the present invention.

  When the identification result obtained by using the identification method described above deviates greatly from the rated value of the motor constant or the initial set value, it can be determined that the motor or the inverter is out of order. For example, when the identification result of the motor winding resistance is very large, it can be determined that the motor connection may be disconnected.

  8 to 10 show simulation results for confirming the effectiveness of the constant identification method.

FIG. 8 shows a simulation result of the winding resistance identification method of the present invention under the condition that an error of + 20% is set to the motor winding resistance initial setting value (r ^* 0). The dc-axis current command waveform 60 at startup is the dc-axis current command value, the second dc-axis current command waveform 61 at startup is the second dc-axis current command value, and the qc-axis current command 62 at startup is the qc-axis current. The command value, 63 is a motor winding resistance identification value, and 64 is a motor winding resistance. It has been found that the identification value 63 of the motor winding resistance is gradually adjusted to the motor winding resistance constant 64.

  FIG. 9 shows a simulation result of the constant identification method of the present invention under the condition that an error of −20% is set to the initial set value of the induced voltage constant and the virtual inductance of the control system.

  FIG. 10 shows a simulation result of the constant identification method of the present invention under the condition that an error of + 20% is set to the initial set value of the induced voltage constant and the virtual inductance of the control system.

  9 and 10, 65 indicates a motor current waveform, 66 indicates a motor induced voltage constant, 67 indicates an identification value of the motor induced voltage constant, 68 indicates a motor virtual inductance constant, and 69 indicates a motor virtual inductance identification value.

  The induced voltage constant was identified during the time axis 6s-8s. As a result, the identification value of the induced voltage constant is adjusted to substantially match the motor constant. Next, the identification result of the induced voltage constant was held between the time axes 8 s to 10 s to identify the virtual inductance. As a result, the identification value of the virtual inductance is also adjusted so as to substantially match the motor constant.

  From the above simulation results, according to this embodiment, even if there is an initial error in the motor constant setting value of the control system, the constant setting value of the control system is adjusted to match the motor constant by the automatic identification operation. . Further, since the constant setting value of the control system changes gently during the identification operation, the influence on the control system stability is small.

  In this embodiment, the motor current is detected from the bus current using a shunt resistor. However, the current is not limited to the shunt resistor but may be detected by a current sensor using a Hall element or the like. Naturally, the three-phase motor current may be directly detected using a current sensor instead of the bus current.

(Second Embodiment)
The configuration of the motor control device of the second embodiment of the present invention is the same as that shown in FIG. However, the vector control method inside the controller 6 is different.

  FIG. 11 is a functional block configuration diagram of the voltage command controller 12 and the motor constant identifier 13 according to the second embodiment of the present invention. The same reference numerals as those in FIG. 5 perform the same operations.

The difference from FIG. 5 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 (Equation 15), and the winding resistance identification integration. This is because the input of the current controller 39 is changed to ΔV _dc of the current controller 39, and the inputs of the induced voltage constant identification integrator 32 b and the virtual inductance identification integrator 32 c are changed to ΔV _qc of the current controller 40. The current reproduction and the speed & phase estimation process are the same as those in the first embodiment.

Here, ΔV _dc and ΔV _qc are the dc-axis and qc-axis voltage command compensation values of the current controllers 39 and 40.

  As in the first embodiment, when the output voltage command of Formula (15) is applied to the motor via the inverter, the relationship between the motor detection current and the voltage command is approximated by Formula (5) in a steady state. Is called.

As shown in FIG. 6, at the beginning of the motor start (from the time (t0) to the time (t1)), the motor rotation speed command value ω ₁ ^* is set to 0, and the current according to the dc-qc axis current command value When the command is given, the motor rotor is positioned.

  Under the above conditions, the voltage command value is the following equation from the equation (15).

  Moreover, the following formula is obtained from the formula (5).

  From the equation (15) and the equation (17), the following equation is obtained.

Since the d-axis current controller 39 is provided, the dc-axis motor current detection value (I _dc ) and the dc-axis current command value (I _dc ^* ) are considered to be substantially equal. Therefore, when Expression (18) is modified, Expression (19) is obtained.

  From the equation (19), it was found that the winding resistance error can be calculated from the output of the d-axis current controller 39 during the motor positioning operation.

In the steady state during motor rotation, the motor rotation speed command value (ω ₁ ^* ) and actual value (ω ₁ ), the dc-axis motor current detection value (I _dc ), and the first dc-axis current command value (I _dc ^* ) Is almost equal. Furthermore, when it is assumed that the motor is rotating at a medium to high speed or that the error of the resistance setting value is small, the following equation is established from the equations (15) and (5).

  By transforming the above equation, the following equation (21) is obtained.

Therefore, if the dc-axis current command value I _dc ^* is set to 0, an error of the induced voltage constant (ΔKe = Ke−Ke ^* ) can be obtained from ΔV _{qc of the} current controller from the equation (21).

Next, after the identification of the induced voltage constant is completed (assuming Ke ^* = Ke), when a predetermined value (= I _dc ^* _{_at} ) is given to the dc-axis current command value I _dc ^* , the equation (21) is obtained. The error of the motor virtual inductance L ^* is obtained by the following equation.

From the equations (19), (22) and (23), the relationship between the winding resistance of the motor and the output ΔV _{dc of} the current controller, and the error between the induced voltage constant and the virtual inductance is related to the ΔV _{qc of the} current controller. I understood. Therefore, as in the first embodiment, ΔV _dc and ΔV _qc can be processed by an integrator to identify a control constant.

  The operation principle of the motor constant identifier 13 shown in FIG. 11 is the same as that of FIG. 5 of the first embodiment. The constant identification procedure is also performed in the same manner as in the first embodiment.

  The above is the description of the identification method according to the second embodiment of the present invention.

  As in the first embodiment, the motor current is detected from the bus current using a shunt resistor in the present embodiment. However, the motor current is not limited to the shunt resistor but is actually detected by a current sensor using a Hall element or the like. It may be detected. Naturally, the three-phase motor current may be directly detected using a current sensor instead of the bus current.

(Third embodiment)
A third embodiment will be described with reference to FIGS.

  FIG. 12 shows the configuration of the motor control apparatus according to the third and fourth embodiments of the present invention. In the present embodiment, the position sensor 101 is used to detect the position of the motor rotor, which is different from the first embodiment. Otherwise, the same reference numerals as those in FIG. 1 are the same.

  FIG. 13 is a functional block configuration diagram of the controller 6 of the motor control device according to the third and fourth embodiments of the present invention, and each function is realized by a CPU (computer) and a program. The same reference numerals as those in FIG. 2 perform the same operations.

  The speed & phase calculator 102 calculates the motor rotation speed and the rotor position using the position sensor signal output from the position sensor 101. Since the position of the motor rotor can be detected, the control system axis coincides with the motor rotor axis.

  FIG. 14 is a detailed configuration of the voltage command controller 12 and the motor constant identifier 13 of the present embodiment. Here, the calculation processing of the vector calculator 42 is executed according to the equation (24).

Here, L _d ^* and L _q ^* are set values of inductances of the motor d axis and the q axis.

  When the output voltage command of the formula (24) is applied to the motor via the inverter, the relationship between the motor detection current and the voltage command is approximated by the formula (25) in a steady state.

Here, L _d and L _q are inductance values of the motor d-axis and the q-axis.

As in the first embodiment, the difference (I _d ^{** −} I _d ^* ) of the current command value is integrated via the input switch while giving the waveform shown in FIG. 6 to the current command value in the motor stop state. When input to the device 32a, the motor winding resistance set value r ^* can be identified. Further, when the motor command is set to I _d ^* to 0 and the current command value difference (I _d ^{** −} I _d ^* ) is input to the integrator 32b via the input switch, the motor induced voltage The constant set value Ke ^* can be identified; after that, while setting I _d ^* to a predetermined value, the difference (I _d ^{** −} I _d ^* ) of the current command value is input to the integrator 32d via the input switch. When input, the motor d-axis inductance set value L _d ^* can be identified.

Further, when the difference (I _q ^* −I _q ^** ) of the current command value is input to the integrator 32e via the input switch in the motor operating state, the motor q-axis inductance set value L _q ^* can be identified. .

  Further, if the induced voltage constant and the inductance identification operation are repeated several times, the identification accuracy can be further improved.

  As described above, the motor constants necessary for realizing high control performance can be identified using the motor constant identifier of the present embodiment.

(Fourth embodiment)
The difference between the fourth embodiment and the third embodiment of the present invention is the vector control inside the controller 6.

  FIG. 15 is a functional block configuration diagram of the voltage command controller 12 and the motor constant identifier 13 according to the fourth embodiment of the present invention. The same reference numerals as those in FIG. 11 denote the same operations.

The voltage command values V _d ^* and V _q ^* are the sum of the output of the vector computing unit 42 and the output of the current control unit, as shown in Equation (26).

Here, ΔV _d and ΔV _q are outputs of the current controller.

  Identification of the motor winding resistance, the induced voltage constant and the d-axis inductance is performed by the same method as in the first to third embodiments.

Identification of the q-axis inductance is performed by inputting the output ΔV _d of the d-axis current controller to the integrator 32e via the input switch in the motor operating state.

(Fifth embodiment)
FIG. 16 is an external view of the motor drive device module 200 according to the fifth embodiment of the present invention, and shows one form of the 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 bus current detector 4, the DC voltage detector 5, and the controller illustrated in FIG. 6 is directly mounted, and the inverter 3 is mounted as a semiconductor element 202 formed 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, automatic identification of constants necessary for the control system can be realized at startup or during operation, so that high control performance can be realized even if there are initial setting errors or fluctuations of motor constants. Further, when driving different motors, it is not necessary to reset the control constant, so that the versatility and convenience of the motor driving apparatus using the module of this embodiment can be improved.

(Sixth embodiment)
FIG. 17 is a configuration diagram of a refrigeration apparatus such as an air conditioner or a refrigerator using the motor driving apparatus according to the sixth 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 compressor motor 308 is disposed inside the compressor 305 using a permanent magnet synchronous motor. The motor driving device 307 converts the alternating current power into direct current and provides it to the motor driving inverter to drive the motor.

  By using the motor drive device of the first and second embodiments and the motor drive module of the fifth embodiment, automatic identification of motor constants and control constants can be performed during start-up or during operation under the condition that there is no motor position sensor. Therefore, high control performance can be ensured even if the motor constant varies or fluctuates.

  In addition, when the constant identification method of the present invention is used as a refrigeration apparatus, motor constants can be identified under each load condition (operating condition), and the maximum efficiency operation can always be performed. Improvement). For example, it is possible to always reduce power consumption by identifying each of the air conditioner operating states (minimum capacity, intermediate capacity, rated capacity, etc.) and storing the identification results in a constant storage unit.

It is a block diagram of the motor control apparatus which is one Embodiment of this invention. It is a functional block block diagram of the control part of the motor control apparatus which is one Embodiment of this invention. It is a control system estimation axis | shaft of a motor control apparatus which is one Embodiment of this invention, a motor rotor axis | shaft, and a motor maximum torque axis | shaft. It is a block block diagram of the speed & phase estimator of the motor control apparatus which is one Embodiment of this invention. It is a block block diagram of the voltage command controller and motor constant identifier of the motor control apparatus which is one Embodiment of this invention. It is a current command waveform diagram at the time of motor startup. It is a current command waveform diagram at the time of motor constant identification operation. It is a simulation waveform figure of winding resistance identification. It is a simulation waveform diagram of an induced voltage constant and virtual inductance identification. It is a simulation waveform diagram of an induced voltage constant and virtual inductance identification. It is a block block diagram of the voltage command controller and motor constant identifier of the motor control apparatus which is one Embodiment of this invention. It is a block diagram of the motor control apparatus which is one Embodiment of this invention. It is a functional block block diagram of the control part of the motor control apparatus which is one Embodiment of this invention. It is a block block diagram of the voltage command controller and motor constant identifier of the motor control apparatus which is one Embodiment of this invention. It is a block block diagram of the voltage command controller and motor constant identifier of the motor control apparatus which is one Embodiment of this invention. It is an external view of the module of the motor control apparatus which is one Embodiment of this invention. It is a block diagram of the freezing apparatus which is one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet synchronous motor 2 DC power supply 3 Inverter 4 Bus current detector 5 DC voltage detector 6 Controller (control means)
DESCRIPTION OF SYMBOLS 10 Speed controller 11 d-axis current command generator 12 Voltage command controller 13 Motor constant identifier 14 2 axis 3 phase converter 15 Speed & phase estimator 16 3 phase 2 axis converter 17 Current reproduction calculator 18 PWM controller 19, 23, 37, 38, 41, 105 Subtractor 20 Axis error calculator 21 Speed estimator 22 Phase calculator 30 Input switch 31 Identification control units 32a, 32b, 32c, 32d, 32e Integrators 33a, 33b, 33c , 33d, 33e Constant saver 34, 35, 36, 43, 44, 103, 104 Adder 39, 40 Current controller 42 Vector calculator 50 dc-axis current command waveform 51 qc-axis current command waveform 60 dc-axis at startup Current command waveform 61 Second dc-axis current command waveform 62 at startup qc-axis current command waveform 63 at startup Motor winding resistance identification value 64 Motor winding resistance constant 65 Motor current waveform 66 Motor induced voltage constant 67 Induced voltage constant identification value 68 Motor virtual inductance constant 69 Motor virtual inductance identification value 101 Position sensor 102 Speed & phase calculator 200 Module 201 Controller board 202 Semiconductor element (power module)
300 Refrigeration units 301, 302 Heat exchangers 303, 304 Fan 305 Compressor 306 Piping 307 Motor drive unit 308 Compressor motor I _sh bus current V _u ^* , V _v ^* , V _w ^* Three-phase voltage command value I _u , I _v, the phase Δθc axis error d of I _w three-phase motor current theta _dc control shaft, q motor rotor shaft dc, qc control shaft do, qo maximum motor torque shaft I _dc, I _{qc dc-qc-axis} current detection value I _dc ^* , I _qc ^* dc-qc axis current command value I _dc ^** , I _qc ^** Second dc-qc axis current command value V _dc ^* , V _qc ^* dc-qc axis voltage command value ΔV _dc , ΔV _qc dc-qc axis voltage command compensation value r motor winding resistance L ^* motor virtual inductance L _d motor d-axis inductance L _q motor q-axis inductance Ke motor induced voltage constant r ^* motor winding resistance setting value L ^** motor virtual inductance setting value L _d ^* mode d-axis inductance setting value L _q ^* Motor q-axis inductance setting value Ke ^* motor induced voltage constant setting value r ^* 0 a motor winding resistance Initial setting L ^** 0 Motor virtual inductance initial set value L _d ^* 0 a motor d-axis inductance Initial setting value L _q ^* 0 Motor q-axis inductance initial setting value Ke ^* 0 Motor induced voltage constant setting value Δr Motor winding resistance error ΔL ^* Motor virtual inductance error ΔL _d Motor d-axis inductance error ΔL _q Motor q-axis inductance error ΔKe Motor induced voltage constant error I _{dc_at} ^* L ^* or L _d Current command predetermined value at identification ωm Motor rotation speed detection value or estimated value ω ₁ ^* Motor rotation speed command value

Claims (7)

Permanent magnet synchronous motor, inverter circuit connected to a DC power source and driving the permanent magnet synchronous motor, motor current detecting means for detecting motor current from the output current of the inverter circuit or the bus current on the DC side, and motor current detection In a motor drive device comprising a control means for controlling the rotation speed of the permanent magnet synchronous motor using a value,
The control means includes
Voltage applied to the permanent magnet synchronous motor using the first dc axis current command value I _dc ^* and the first qc axis current command value I _qc ^* generated based on the speed command to the permanent magnet synchronous motor A voltage command control unit that calculates a command value is provided.
The voltage command control unit
A second dc calculated from a deviation between the dc-axis current detection value I _dc and the qc-axis current detection value I _qc and the first dc-axis current command value I _dc ^* and the first qc-axis current command value I _qc ^* Axis current command value I _dc ^** and second qc axis current command value I _qc ^** , motor rotation speed command value ω ₁ ^* , motor winding resistance setting value r ^* , and motor virtual inductance setting value L ^{* The} dc-axis voltage command value V _dc ^* and the qc-axis voltage command value V _qc ^* to be applied to the permanent magnet synchronous motor using ^* and the motor induced voltage constant set value Ke ^* are obtained from the following motor voltage equation: Calculate
[Motor voltage equation]

The dc-axis voltage command value V _dc ^* and the qc-axis voltage command value V _qc ^* , the dc-axis current detection value I _dc and the qc-axis current detection value I _qc , the winding resistance setting value r ^*, and the virtual inductance setting A means for calculating an axis error between the control system axis and the motor maximum torque axis based on the value L ^** and controlling the axis error to 0;
In a state where the motor is rotating, the first dc-axis current command value I _dc ^* is set to a predetermined value other than 0 at a predetermined time after completion of identification of the motor-induced voltage constant , and the second dc-axis An error of the motor virtual inductance set value is calculated from the current command value I _dc ^** and the first dc-axis current command value I _dc ^* using an integrator, and added to the motor virtual inductance set value L ^** . Thus , a motor drive device characterized by identifying a motor virtual inductance . Permanent magnet synchronous motor, inverter circuit connected to a DC power source and driving the permanent magnet synchronous motor, motor current detecting means for detecting motor current from the output current of the inverter circuit or the bus current on the DC side, and motor current detection In a motor drive device comprising a control means for controlling the rotation speed of the permanent magnet synchronous motor using a value,
The control means includes
Voltage applied to the permanent magnet synchronous motor using the first dc axis current command value I _dc ^* and the first qc axis current command value I _qc ^* generated based on the speed command to the permanent magnet synchronous motor A voltage command control unit that calculates a command value is provided.
The voltage command control unit
A dc-axis voltage command calculated from a deviation between the dc-axis current detection value I _dc and the qc-axis current detection value I _qc and the first dc-axis current command value I _dc ^* and the first qc-axis current command value I _qc ^* Compensation value ΔV _dc and qc-axis voltage command compensation value ΔV _qc , motor rotation speed command value ω ₁ ^* , motor winding resistance setting value r ^* , motor virtual inductance setting value L ^** , and motor induced voltage constant setting Using the value Ke ^* , a dc-axis voltage command value V _dc ^* and a qc-axis voltage command value V _qc ^* to be applied to the permanent magnet synchronous motor are calculated from the following motor voltage equation:
[Motor voltage equation]

The dc-axis voltage command value V _dc ^* and the qc-axis voltage command value V _qc ^* , the dc-axis current detection value I _dc and the qc-axis current detection value I _qc , the winding resistance setting value r ^*, and the virtual inductance setting A means for calculating an axis error between the control system axis and the motor maximum torque axis based on the value L ^** and controlling the axis error to 0;
In a state where the motor is rotating, the first dc-axis current command value I _dc ^* is set to a predetermined value other than 0 at a predetermined time after the identification of the motor-induced voltage constant is completed , and the qc-axis voltage command compensation value is set. A motor drive device characterized by calculating an error of a motor virtual inductance set value from ΔV _qc using an integrator and adding the error to the motor virtual inductance set value L ^** to identify the motor virtual inductance . The motor drive device according to claim 1,
At a predetermined time before starting the motor, the motor rotation speed command value ω ₁ ^{* is set} to 0, the dc-axis current command value I _dc ^* is set to a predetermined value, and the qc-axis current command value I _qc ^* is set to 0,
Based on the deviation between the second dc-axis current command value I _dc ^** and the dc-axis current command value I _dc ^* , an error of the motor winding resistance setting value is calculated using an integrator, and the motor winding resistance A motor drive device characterized by identifying a motor winding resistance by adding to a set value r ^* . The motor drive device according to claim 1,
The dc-axis current command value I _dc ^* is set to 0 at a predetermined time while the motor is rotating ,
An error of a motor induced voltage constant set value is calculated from the second dc-axis current command value I _dc ^** using an integrator, and added to the motor induced voltage constant set value Ke ^* to obtain a motor induced voltage. A motor driving device characterized by identifying a constant . In the motor drive device according to claim 2,
At a predetermined time before starting the motor, the motor rotational speed command value ω ₁ ^* 0, the dc-axis current command value I _dc ^* Is a predetermined value, the qc-axis current command value I _qc ^* Set to 0,
The dc axis voltage command compensation value ΔV _dc From the above, the error of the motor winding resistance setting value is calculated using an integrator, and the motor winding resistance setting value r is calculated. ^* A motor drive device characterized by identifying the motor winding resistance by adding to. In the motor drive device according to claim 2,
The dc-axis current command value I at a predetermined time while the motor is rotating. _dc ^* Set to 0,
Qc-axis voltage command compensation value ΔV _qc Then, an error of the motor induced voltage constant set value is calculated using an integrator, and the motor induced voltage constant set value Ke is calculated. ^* A motor drive device characterized by identifying a motor induced voltage constant by adding to In a refrigeration apparatus comprising a compressor, a permanent magnet motor that drives the compressor, a heat exchanger, and a fan,
A refrigeration apparatus comprising the motor driving apparatus according to any one of claims 1 to 6 as a motor driving apparatus for driving the permanent magnet motor.

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