JPWO2020194396A1 - Permanent magnet synchronous machine control device - Google Patents

Abstract

An object of the present invention is to provide a control device for a permanent magnet synchronous machine capable of calculating a correction value of a magnetic pole position with a simple configuration. The first correction phase calculation unit (9) of the control device (1) calculates the first correction phase based on the command value of the d-axis voltage calculated by the current control unit (8). The second correction phase calculation unit (10) of the control device (1) has at least one of the command value of the q-axis current calculated by the current control unit (8) or the actual value of the q-axis current of the permanent magnet synchronous machine, and is permanent. The second correction phase is calculated based on the parameters of the magnet synchronous machine. The conversion unit of the control device (1) performs coordinate conversion on the dq coordinates in the current control unit (8) using the electric angle of the permanent magnet synchronous machine corrected by the third correction phase. The third correction phase is the sum of the first correction phase and the second correction phase.

Description

The present invention relates to a control device for a permanent magnet synchronous machine.

Patent Document 1 discloses an example of a control method for a permanent magnet synchronous motor. In this method, the position of the rotor is corrected by the phase correction value. The phase correction value is calculated during the adjustment after the motor is installed.

Japanese Patent No. 3336870

However, in Patent Document 1, the phase correction value is calculated by measuring the drive voltage. For this reason, the control device requires a voltage sensor that measures the drive voltage. This complicates the hardware configuration of the control device.

The present invention has been made to solve such a problem. An object of the present invention is to provide a control device for a permanent magnet synchronous machine capable of calculating a correction value of a magnetic pole position with a simple configuration.

The control device for the electric motor according to the present invention is a permanent magnet synchronous machine using a current command generator that generates command values of d-axis current and q-axis current of the permanent magnet synchronous machine and a command value generated by the current command generator as inputs. The current control unit that calculates the command values of the d-axis voltage and the q-axis voltage, the first correction phase calculation unit that calculates the first correction phase based on the command value of the d-axis voltage calculated by the current control unit, and the current. The second correction phase calculation unit that calculates the second correction phase based on at least one of the command value of the q-axis current calculated by the control unit or the actual value of the q-axis current of the permanent magnet synchronous machine and the parameters of the permanent magnet synchronous machine. And a conversion unit that performs coordinate conversion on the dq coordinate in the current control unit using the electric angle of the permanent magnet synchronous machine corrected by the third correction phase, which is the sum of the first correction phase and the second correction phase. , Equipped with.

According to the present invention, the control device includes a current command generation unit, a current control unit, a first correction phase calculation unit, a second correction phase calculation unit, and a conversion unit. The current command generator generates command values for the d-axis current and the q-axis current of the permanent magnet synchronous machine. The current control unit calculates the command values of the d-axis voltage and the q-axis voltage of the permanent magnet synchronous machine by inputting the command values generated by the current command generation unit. The first correction phase calculation unit calculates the first correction phase based on the command value of the d-axis voltage calculated by the current control unit. The second correction phase calculation unit is based on at least one of the command value of the q-axis current calculated by the current control unit or the actual value of the q-axis current of the permanent magnet synchronous machine and the parameters of the permanent magnet synchronous machine. Is calculated. The conversion unit performs coordinate conversion on the dq coordinate in the current control unit using the electric angle of the permanent magnet synchronous machine corrected by the third correction phase, which is the sum of the first correction phase and the second correction phase. As a result, the control device can calculate the correction value of the magnetic pole position with a simple configuration.

It is a block diagram which shows the structure of the control device which concerns on Embodiment 1. FIG. It is a block diagram which shows the structure of the 1st correction phase calculation part which concerns on Embodiment 1. FIG. It is a figure which shows the relationship between the coordinate system by the actual magnetic pole position of the electric motor which concerns on Embodiment 1 and the coordinate system which includes the deviation of the error corresponding to the decoupling voltage. It is a figure which shows the hardware composition of the main part of the control device which concerns on Embodiment 1. FIG. It is a block diagram which shows the structure of the control device which concerns on Embodiment 2. FIG. It is a block diagram which shows the structure of the operation mode setting part which concerns on Embodiment 2. FIG. It is a flowchart which shows the example of the operation in the learning operation of the control device which concerns on Embodiment 2. It is a flowchart which shows the example of the operation in the learning operation of the control device which concerns on Embodiment 2. It is a flowchart which shows the example of the operation in the normal operation of the control device which concerns on Embodiment 3.

A mode for carrying out the present invention will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and duplicate description will be appropriately simplified or omitted.

Embodiment 1.
FIG. 1 is a block diagram showing a configuration of a control device according to the first embodiment.

The control device 1 is a device that drives a permanent magnet synchronous machine. In this example, the permanent magnet synchronous machine is a motor 2. The electric motor 2 is, for example, a three-phase electric motor. In this example, the shape of the rotor of the motor 2 is, for example, a non-salting shape. The motor 2 is applied to, for example, an elevator. The electric motor 2 is applied to, for example, an elevator hoisting machine or a door.

Generally, in the control of a three-phase AC motor, the three-phase current and voltage including the U-phase, V-phase, and W-phase are often converted into two axes and handled. Of the three phases, the coordinate system on the two stationary axes in which the α axis is aligned with the U phase axis is called the α-β coordinate system. The coordinate system on the two axes of rotation in which the d axis is aligned with the direction of the magnetic field of the rotor is called the dq coordinate system. _{The electric angle θ re} of the rotor of the motor 2 is the rotation angle of the d−q coordinate system as seen from the α−β coordinate system.

The control device 1 includes a current detector 3, a rotation angle detector 4, a phase calculation unit 5, a speed calculation unit 6, a current command generation unit 7, a current control unit 8, and a first correction phase calculation unit 9. A second correction phase calculation unit 10, a coordinate conversion unit 11, and a power converter 12 are provided.

The current detector 3 is a device that measures the current flowing through the motor 2. The current detector 3 is provided in the wiring of each phase so that, for example, the three-phase phase current input to the motor 2 can be measured. In this example, the current detector 3 _{measures the U-phase current i U} , the V-phase current i _V , and the W-phase current i _W , respectively.

The rotation angle detector 4 is a device that detects the rotation angle of the electric motor 2. The rotation angle detector 4 includes, for example, an optical encoder, a resolver, a magnetic sensor, and the like.

The phase calculation unit 5 is a part that calculates _{the electric angle θ re} of the rotor of the motor 2. In the calculation of the electric angle θ _re in the phase calculation unit 5, for example, the rotation angle of the motor 2 detected by the rotation angle detector 4 is used.

The speed calculation unit 6 is a part that calculates the rotation speed ω of the electric motor 2. In the calculation of the rotation speed ω, for example, the time derivative of the rotation angle of the motor 2 detected by the rotation angle detector 4 is used.

Current command generator 7, as a current command value in the d-q coordinate system, which is a command value i _{d ^*,} and the q-axis portion for generating a command value i _q ^* of the current of the d-axis current. In this example, when the shape of the rotor is a non-slip pole type, the command value _id ^* of the d-axis current is set to 0. _{The command value i q} ^* of the q-axis current is calculated by, for example, converting the command value of the torque calculated based on the deviation of the command value of the rotation speed of the motor 2 and the actual value into the command value of the current. The torque command value is calculated by, for example, P control (P: Proportional), PI control (I: Integral), PID control (D: Differential), or other control method.

The current control unit 8 is a part that calculates _{the command value v d of the d-} axis voltage and the command value v _q of the q-axis voltage as the voltage command values in the d-q coordinate system. Calculation of the voltage command value by the current control unit 8, d-q command value of the current in the coordinate system as _i ^{d *} and _i ^{q *,} and the actual values _{i d} and _{i q} of the current in the d-q coordinate system, the electric motor 2 The rotation speed ω of is input.

The current control unit 8, a d-q command value of the current in the coordinate system _i ^{d *} and _i ^{q *,} based on a deviation between actual value _{i d} and _{i q} of the current in the d-q coordinate system, the vector control Calculate the compensation voltage that causes the actual value to follow the command value. The compensation voltage is calculated by feedback control. The compensation voltage is calculated by, for example, P control, PI control, PID control, or other control method.

Also, in general, voltage interference occurs between the d-axis and the q-axis. Therefore, in the current control unit 8, feedforward compensation is performed by the non-interfering voltage that de-interferes with the voltage interference. The non-interfering voltage is calculated by the electric angular velocity of the motor 2, the actual value of the current in the dq coordinate system, and the parameters of the motor 2. The electric angular velocity is calculated by multiplying the rotational speed ω of the motor 2 calculated by the speed calculation unit 6 by the number of pole pairs of the motor 2. The parameters of motor 2 include, for example, inductance and induced voltage constants.

The current control unit 8 outputs the sum of the compensation voltage and the interference voltage obtained as described above as a voltage command value in the dq coordinate system.

The first correction phase calculation unit 9 is a portion for calculating _{the first correction phase Δθ 1.} The second correction phase calculation unit 10 is a part that calculates _{the second correction phase Δθ 2.} The first correction phase Δθ ₁ and the second correction phase Δθ ₂ are used to correct the _{electric angle θ re} calculated by the phase calculation unit 5.

The coordinate conversion unit 11 is a portion that performs coordinate conversion on the dq coordinates in the current control unit 8 based on the corrected electric angle. The coordinate conversion unit 11 is an example of the conversion unit. The coordinate conversion unit 11 includes a 3-phase / 2-axis conversion unit 13 and a 2-axis / 3-phase conversion unit 14. The three-phase / two-axis converter 13 converts the three-phase currents i _U , i _V , and i _{W of the motor 2 detected by the current detector 3 into the two-axis currents i d} and i _q in the dq coordinate system. This is the part that converts the coordinates to. The 2-axis / 3-phase conversion unit 14 sets the 2-axis voltage command values v _d and v _q in the d-q coordinate system calculated by the current control unit 8 into the 3-phase voltage command values v _U , v _V , and v. _This is the part that converts the coordinates to W.

The power converter 12 is a device that converts a power supply voltage (not shown) into a variable voltage variable frequency voltage based on an input voltage command value. In this example, the power converter 12 includes a converter that converts an AC power supply voltage into a DC voltage, and an inverter that converts the DC voltage converted by the converter into a variable voltage variable frequency AC voltage.

Subsequently, an example of correcting the electric angle in the control device 1 will be described with reference to FIGS. 2 and 3.

FIG. 2 is a block diagram showing a configuration of a first correction phase calculation unit according to the first embodiment.

The first correction phase calculation unit 9 calculates the first correction phase Δθ _{1 based on the command value v d} of the d-axis voltage output by the current control unit 8. The first correction phase calculation unit 9 includes a gain amplifier 15 and an integrator 16. The gain amplifier 15 multiplies the command value of the d-axis voltage by a constant and outputs the output to the integrator 16. The integrator 16 integrates the input values and outputs them as _{the first correction phase Δθ 1.}

In this example, the command value _id ^* of the d-axis current is set to 0. _{If the electric angle θ re} calculated by the phase calculation unit 5 does not deviate from the actual magnetic pole position of the motor 2, and the deviation between the command value and the actual value of the d-axis current by the current feedback control is 0, the current. The control unit 8 calculates the compensation voltage of the d-axis as 0 in the steady state. On the other hand, when the electric angle θ _re calculated by the phase calculation unit 5 deviates from the actual magnetic pole position of the motor 2, the q-axis current flows into the d-axis, so even if the d-axis current is controlled to 0, the d-axis current flows. The compensation voltage of is not 0.

By utilizing this characteristic, the first correction phase calculation unit 9 calculates the first correction phase Δθ _{1 until the command value v d} of the d-axis voltage becomes 0. Accordingly, the first correction phase [Delta] [theta] ₁ is a correction value for correcting the deviation between the actual magnetic pole position of the electric angle theta _re and electric motor 2 to the phase calculating unit 5 calculates.

Here, the command value v _d of the d-axis voltage includes the non-interfering voltage in addition to the compensation voltage. Therefore, the first correction phase includes an error corresponding to the non-interfering voltage. _{Therefore, the second correction phase calculation unit 10 calculates the second correction phase Δθ 2} , which is a correction value for correcting the error corresponding to the non-interfering voltage.

FIG. 3 is a diagram showing the relationship between the coordinate system according to the actual magnetic pole position of the motor according to the first embodiment and the coordinate system including the deviation of the error corresponding to the decoupling voltage.

In FIG. 3, the d-axis and the q-axis represent the dq coordinate system based on the actual magnetic pole position of the motor 2. The dc and qc axes represent a dq coordinate system that includes an error shift corresponding to the decoupling voltage. At this time, there is an angular error of Δθ between the d-axis and the dc-axis and between the q-axis and the qc-axis.

The actual d-axis current and q-axis current in the motor 2 are expressed by the following equations (1) and (2) using the _{current value i qc from the relationship of the coordinate system shown in FIG.} Here, the current value i _qc is a current value treated as an actual value of the q-axis current in the control device 1 when there is no correction by the second correction phase Δθ _2. Further, in this example, the d-axis current is controlled to 0.

Further, using the equations (1) and (2), the voltages v _d and v _q in the actual dq coordinate system of the motor 2 are expressed as the following equations (3) and (4). .. Here, R represents a resistance value. L _d and L _q represent the inductance of the d-axis and the q-axis. φ represents the induced voltage constant. ω _re represents the electric angular velocity.

Similar to the equations (1) and (2), the relationship between the d-axis voltage and the q-axis voltage and the dc-axis voltage and the qc-axis voltage is derived from the relationship of the coordinate system shown in FIG. At this time, considering the equations (3) and (4), the dc-axis voltage is expressed as the following equation (5).

Here, since the first term on the right side of the equation (5) is the non-interfering voltage on the dc axis, it can be seen that the second and third terms on the right side are the compensation voltage. Since the first correction phase Δθ _{1 is calculated so that the command value v dc} of the dc-axis voltage in the control device 1 becomes 0, the left side of the equation (5) becomes 0 when the correction by the first correction phase Δθ _{1 is taken into consideration.} Become. At this time, when Eq. (5) is solved for Δθ, Δθ becomes a function of the inductance, the induced voltage constant, and the qc-axis current of the motor 2 as expressed in Eq. (6).

_{That is, Δθ 1} calculated by the first correction phase calculation unit 9 is a value having an error of the equation (6) with respect to the correct correction value of the deviation of the magnetic pole position. In order to correct this error, the second correction phase calculation unit 10 calculates the second correction phase Δθ ₂ by the equation (6) as Δθ ₂ = Δθ. _{Therefore, the third correction phase Δθ 3} , which is the correction value of the deviation of the magnetic pole position, is obtained by adding the first correction phase Δθ ₁ and the second correction phase Δθ _2.

When the actual value of the q-axis current follows the command value by the current control unit 8, the second correction phase calculation unit 10 uses either the command value or the actual value as the q-axis current of the equation (6). You may use it.

The coordinate conversion unit 11 uses the electric angle corrected by adding the third correction phase Δθ _{3 to the electric angle θ re} calculated by the phase calculation unit 5, and uses the coordinates of the dq coordinates in the current control unit 8. Perform the conversion.

As described above, the control device 1 according to the first embodiment converts the current command generation unit 7, the current control unit 8, the first correction phase calculation unit 9, and the second correction phase calculation unit 10. It has a part and. The current command generation unit 7 generates command values for the d-axis current and the q-axis current of the permanent magnet synchronous machine. The current control unit 8 calculates the command values of the d-axis voltage and the q-axis voltage of the permanent magnet synchronous machine by inputting the command values generated by the current command generation unit 7. The first correction phase calculation unit 9 calculates the first correction phase Δθ _{1 based on the command value v d} of the d-axis voltage calculated by the current control unit 8. _{The second correction phase calculation unit 10 is at least one of the command value i q} ^* of the q-axis current calculated by the current control unit 8 _{or the actual value i q} of the q-axis current of the permanent magnet synchronous machine, and the parameters of the permanent magnet synchronous machine. The second correction phase Δθ ₂ is calculated based on. The conversion unit performs coordinate conversion on the dq coordinates in the current control unit 8 using the electric angle of the permanent magnet synchronous machine corrected by the third correction phase Δθ _3. The third correction phase Δθ ₃ is the sum of the first correction phase Δθ ₁ and the second correction phase Δθ _2.

As a result, the control device 1 does not require additional hardware such as a voltage sensor to correct the electrical angle. Therefore, the control device 1 can calculate the correction value of the magnetic pole position with a simple configuration.

Generally, the current control of the electric motor, which is a permanent magnet synchronous machine, is performed based on the current value of the coordinate system on the dq axis, which is the rotating coordinate. Therefore, the magnetic pole position of the rotor of the motor is important information that serves as a reference for current control. Here, in an electric motor such as an elevator that requires low rotation and large torque, a multi-pole design with several tens of magnet poles is often adopted. In this case, the deviation of the rotation angle of the electric motor becomes a large deviation when converted into the electric angle. Therefore, in order to reduce the deviation of the electric angle, not only the detection accuracy of the sensor itself such as the rotation angle detector, but also the mounting accuracy of the sensor is required to be sufficiently high. On the other hand, mounting the device so as to suppress the deviation of the electric angle to several degrees requires a mounting accuracy higher than the accuracy of the electric angle, which leads to an increase in the manufacturing cost of the electric motor.

Therefore, the control device 1 corrects the deviation of the magnetic pole position by the calculated third correction phase Δθ ₃ . As a result, it is possible to prevent the motor 2 from being operated with the magnetic pole positions shifted. The control device 1 can normally control the electric motor 2. Therefore, deterioration and instability of control performance due to displacement of the magnetic pole position can be prevented.

Further, the first correction phase calculation unit 9 calculates the first correction phase based on _{the command value v d} of the d-axis voltage, which is the sum of the compensation voltage and the non-interfering voltage. Compensation voltage is calculated based on the deviation between the command value i _d ^* and actual value i _d of d-axis current. The non-interfering voltage de-interferes the voltage interference between the d-axis and the q-axis.

_{When the electric angle θ re} calculated by the phase calculation unit 5 deviates from the actual magnetic pole position of the motor 2, even if the d-axis current is controlled to 0, the compensation voltage of the d-axis does not become 0. In this way, the command value of the d-axis voltage reflects the deviation of the magnetic pole position. As for the command value of the d-axis voltage, the voltage interference is de-interfered by the non-interfering voltage. Therefore, the first correction phase calculation unit 9 can calculate the first correction phase Δθ ₁ assuming that the d-axis voltage is independent of the q-axis voltage. At this time, the first correction phase Δθ ₁ includes an error due to the non-interfering voltage. The second correction phase Δθ ₂ corrects the error included in the first correction phase Δθ _1. Therefore, the control device 1 can calculate the correction value of the deviation of the magnetic pole position in consideration of the compensation voltage and the non-interfering voltage.

Further, the first correction phase calculation unit 9 calculates the first correction phase Δθ _{1 by multiplying the command value v d} of the d-axis voltage by a constant and integrating.

As a result, the first correction phase calculation unit 9 can calculate the first correction phase Δθ ₁ by a simple method. _{Further, the first correction phase calculation unit 9 calculates the first correction phase Δθ 1 based} on the command value of the d-axis voltage affected by the correction of the electric angle. _{As a result, the first correction phase Δθ 1} is calculated so that the d-axis voltage becomes 0 even if there is an error between the design value of the power supply voltage and the actual value.

_{Further, the second correction phase calculation unit 10 calculates the second correction phase Δθ 2} using the inductance of the permanent magnet synchronous machine and the induced voltage constant as parameters.

As a result, the second correction phase calculation unit 10 can calculate the second correction phase Δθ ₂ based on the known values regarding the permanent magnet synchronous machine.

The current detector 3 may measure only two of the three-phase currents. The current detector 3 may be any device that measures the current flowing through the motor 2, and is not limited to the device that measures the output current of the power converter 12. The current detector 3 may estimate the current of each phase by measuring the bus current of the power converter 12, for example, as in the current measurement method using a one-shunt resistance.

Further, the rotation angle detector 4 may be any device that detects the rotation angle of the electric motor 2, and is not limited to, for example, an encoder. The rotation angle detector 4 may be equipped with, for example, a function of detecting the rotation speed, and may calculate the rotation angle of the electric motor 2 by time integration of the detected rotation speed.

Further, in the calculation of the rotation speed ω, the speed calculation unit 6 may remove noise due to the time derivative of the rotation angle by, for example, smoothing with a low-pass filter. The speed calculation unit 6 may calculate the rotation speed of the electric motor 2 at regular intervals. The speed calculation unit 6 may include means for measuring the time. At this time, the speed calculation unit 6 may calculate the rotation speed for each constant rotation angle.

Further, the current command generation unit 7 may calculate the _{q-axis current command value i q} ^* so as to control the rotation angle of the motor 2. _{Even if the current command generation unit 7 calculates the q-axis current command value i q} ^* by converting the command value of the constant torque into the command value of the current, for example, when the motor 2 is to output a constant torque. good.

Further, the power converter 12 may be any device that converts the voltage of the power supply into a voltage having a variable voltage and a variable frequency based on the input voltage command value, and is not limited to, for example, a device that converts the voltage by a converter and an inverter. The power converter 12 may be a device that directly converts an AC voltage into a voltage having a variable AC voltage and a variable frequency, such as a matrix converter. Further, the power converter 12 may include means for correcting the dead time of the inverter.

Further, the 2-axis / 3-phase converter 14 may be provided in hardware integrated with the power converter 12, for example. That is, the hardware including the power converter 12 and the 2-axis / 3-phase converter 14 is composed of three phases consisting of U-phase, V-phase, and W-phase based on the input of the command values of the d-axis voltage and the q-axis voltage. Variable voltage The voltage of the power supply may be converted to a voltage of a variable frequency.

Further, when the control device 1 sets a value such as a command value of the d-axis current or the d-axis voltage to 0, the control device 1 may set the value to a value that can be regarded as 0.

Subsequently, an example of the hardware configuration of the control device 1 will be described with reference to FIG.
FIG. 4 is a diagram showing a hardware configuration of a main part of the control device according to the first embodiment.

Each function of the control device 1 can be realized by a processing circuit. The processing circuit includes at least one processor 1b and at least one memory 1c. The processing circuit may include at least one dedicated hardware 1a with or as a substitute for the processor 1b and the memory 1c.

When the processing circuit includes the processor 1b and the memory 1c, each function of the control device 1 is realized by software, firmware, or a combination of software and firmware. At least one of the software and firmware is written as a program. The program is stored in the memory 1c. The processor 1b realizes each function of the control device 1 by reading and executing the program stored in the memory 1c.

The processor 1b is also referred to as a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, and a DSP. The memory 1c is composed of, for example, a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, or the like.

When the processing circuit includes dedicated hardware 1a, the processing circuit is realized by, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

Each function of the control device 1 can be realized by a processing circuit. Alternatively, each function of the control device 1 can be collectively realized by a processing circuit. For each function of the control device 1, a part may be realized by the dedicated hardware 1a, and the other part may be realized by software or firmware. In this way, the processing circuit realizes each function of the control device 1 by hardware 1a, software, firmware, or a combination thereof.

Embodiment 2.
In the second embodiment, the differences from the examples disclosed in the first embodiment will be described in detail. As for the features not described in the second embodiment, any of the features of the examples disclosed in the first embodiment may be adopted.

FIG. 5 is a block diagram showing a configuration of the control device according to the second embodiment.

In the motor 2, the deviation of the magnetic pole position is uniquely determined by the mounting state of the motor 2 and the rotation angle detector 4. Therefore, if the mounting state of the motor 2 and the rotation angle detector 4 does not change, the control device 1 has _{the same as the third correction phase Δθ 3} obtained by learning as the correction value for correcting the deviation of the magnetic pole position. You can continue to use the value of.

The motor 2 has a plurality of operation modes. The operation mode of the electric motor 2 includes, for example, a normal operation mode and a learning operation mode. The normal operation mode is, for example, an operation mode in which the normal operation of the electric motor 2 for supplying the driving force to the device provided with the electric motor 2 is performed. The learning operation mode is an operation mode in which the learning operation of the motor 2 for obtaining _{the third correction phase Δθ 3 is performed.} The learning operation is performed, for example, when the motor 2 is installed. The learning operation may be performed when the rotation angle detector 4 is replaced.

Further, when the power supply is restarted after the power supply to the control device 1 is cut off, the mounting state of the motor 2 and the rotation angle detector 4 changes before and after the power supply is cut off due to maintenance of the motor 2 or the like. It may be. At this time, whether or not the third correction phase Δθ ₃ obtained by learning before the power supply is cut off corresponds to the mounting state of the motor 2 and the rotation angle detector 4 after the power supply is cut off. It is unknown. Therefore, the learning operation may be performed when the power supply to the control device 1 is started.

Here, the equations (1) to (6) described in the first embodiment are equations premised on the steady state of the electric motor 2. Therefore, in the learning operation, the third correction phase Δθ ₃ is calculated when the motor 2 is operating at a constant speed and a constant torque, or when the motor 2 can be regarded as operating at a constant speed and a constant torque. NS. That is, in the learning operation, the current command generation unit 7 sets the command value _id ^* of the d-axis current to 0. When the current command generation unit 7 _{calculates the third correction phase Δθ 3} , the command value i of the q-axis current is set so that the rotation speed of the motor 2 becomes constant or the rotation speed of the motor 2 can be regarded as constant. Generate _q ^*.

The control device 1 includes an operation mode setting unit 17. The operation mode setting unit 17 is a part for setting the operation mode of the electric motor 2. The operation mode setting unit 17 has a function of outputting _{the third correction phase Δθ 3} according to the set operation mode of the motor 2.

FIG. 6 is a block diagram showing a configuration of an operation mode setting unit according to the second embodiment.

The operation mode setting unit 17 includes a storage unit 18. The storage unit 18 is a portion that stores _{the third correction phase Δθ 3 obtained in the learning operation.} When the operation mode of the electric motor 2 is the normal operation mode, the operation mode setting unit 17 outputs _{the third correction phase Δθ 3 stored in the storage unit 18.} On the other hand, when the operation mode of the motor 2 is the learning operation mode, the first correction phase Δθ _{1 calculated by the first correction phase calculation unit 9 and the second correction phase Δθ 2} calculated by the second correction phase calculation unit 10 The sum of and is output as the third correction phase Δθ _{3. The storage unit 18 stores, for example, the sum of the first correction phase Δθ 1} and the second correction phase Δθ ₂ as the third correction phase Δθ ₃ when the operation mode is switched from the learning operation mode.

The correction value of the electric angle described in the first embodiment is calculated based on _{the command value v d} of the d-axis voltage which is the sum of the compensation voltage and the non-interfering voltage. Here, depending on the direction and magnitude of the deviation of the magnetic pole position, the command value v _d of the d-axis voltage may take a value close to 0 even though the magnetic pole position is displaced. At this time, the control device 1 may not be able to obtain a correct value as the correction value of the electric angle. _{Therefore, in order to improve the accuracy of the third correction phase Δθ 3} calculated in the learning operation, the control device 1 controls the electric motor 2 in the learning operation, for example, as follows.

7 and 8 are flowcharts showing an example of the operation of the control device according to the second embodiment in the learning operation.

FIG. 7 shows an example of the operation of the control device 1 that improves the accuracy of _{the third correction phase Δθ 3} by changing the rotation speed of the electric motor 2 in the learning operation.

_{In step S71, the control device 1 determines whether the command value v d} of the d-axis voltage is equal to or greater than a preset threshold value. The determination is made, for example, by the operation mode setting unit 17. Here, the threshold value is set based on, for example, a possible deviation of the magnetic pole position, an operating speed of the motor 2 in the learning operation, a parameter of the motor 2, and the like. When the determination result for the command value v _d of the d-axis voltage is No, the operation of the control device 1 proceeds to step S72. If the determination result is Yes, the operation of the control device 1 proceeds to step S73.

In step S72, the control device 1 changes the rotation speed of the electric motor 2 operated at a constant speed. Here, the control device 1 changes the rotation speed of the electric motor 2 according to, for example, the current command value generated by the current command generation unit 7. _{The current command generation unit 7 generates a command value i q} ^* of the q-axis current so that the motor 2 is operated at a constant rotation speed different from the rotation speed currently being operated, for example. After that, the operation of the control device 1 proceeds to step S71.

In step S73, the operation mode setting unit 17 continuously sets the operation mode to the learning operation mode. The control device 1 calculates the third correction phase Δθ _{3 in the learning operation.} The learning operation is completed, for example, when the calculated third correction phase Δθ ₃ does not change. When the learning operation is completed, the storage unit 18 of the operation mode setting unit 17 stores the calculated third correction phase Δθ ₃ . After that, the operation of the control device 1 in the learning operation ends.

FIG. 8 shows an example of the operation of the control device 1 that improves the accuracy of _{the third correction phase Δθ 3} by changing the rotation direction of the electric motor 2 in the learning operation.

_{In step S81, the control device 1 determines whether the command value v d} of the d-axis voltage is equal to or greater than a preset threshold value. The determination is made, for example, by the operation mode setting unit 17. Here, the threshold value is set based on, for example, a possible deviation of the magnetic pole position, an operating speed of the motor 2 in the learning operation, a parameter of the motor 2, and the like. When the determination result for the command value v _d of the d-axis voltage is No, the operation of the control device 1 proceeds to step S82. If the determination result is Yes, the operation of the control device 1 proceeds to step S83.

In step S82, the control device 1 changes the rotation direction of the electric motor 2 operated at a constant speed. Here, the control device 1 changes the rotation direction of the motor 2 according to the current command value generated by the current command generation unit 7, for example. _{The current command generation unit 7 generates a command value i q} ^* of the q-axis current so that the motor 2 is operated in a rotation direction different from the rotation direction currently being operated, for example. After that, the operation of the control device 1 proceeds to step S81.

In step S83, the operation mode setting unit 17 continuously sets the operation mode to the learning operation mode. The control device 1 calculates the third correction phase Δθ _{3 in the learning operation.} The learning operation is completed, for example, when the calculated third correction phase Δθ ₃ does not change. When the learning operation is completed, the storage unit 18 of the operation mode setting unit 17 stores the calculated third correction phase Δθ ₃ . After that, the operation of the control device 1 in the learning operation ends.

As described above, the control device 1 according to the second embodiment includes an operation mode setting unit 17. The operation mode setting unit 17 sets the operation mode of the permanent magnet synchronous machine. The operation mode setting unit 17 has a storage unit 18. The storage unit 18 stores the third correction phase Δθ ₃ calculated when the operation mode is the learning operation mode. When the operation mode is the normal operation mode, the conversion unit performs coordinate conversion using the electric angle corrected by _{the third correction phase Δθ 3 stored in the storage unit 18.}

While the mounting state of the motor 2 and the rotation angle detector 4 does not change, the conversion unit can continue to use _{the same value already obtained by learning as the third correction phase Δθ 3.} As a result, the control device 1 does not need to calculate the correction value of the deviation of the magnetic pole position each time.

Further, when the operation mode is the learning operation mode, the current command generation unit 7 sets the command value v _d of the d-axis current to 0. _{At this time, the current command generation unit 7 generates a command value i q} ^* of the q-axis current so that the rotation speed of the permanent magnet synchronous machine becomes constant.

As a result, the learning operation is performed under the condition that the rotation speed of the electric motor 2 is constant. Therefore, the condition that the learning of the correction value of the magnetic pole position includes an error is avoided. Therefore, the control device 1 can control the motor 2 more stably based on the magnetic pole position corrected with higher accuracy.

Further, when the command value v _d of the d-axis voltage is smaller than the preset threshold value when the operation mode is the learning operation mode, the current command generation unit 7 sets the rotation speed of the permanent magnet synchronous machine in the learning operation mode. _{The command value i q} ^* of the q-axis current is generated so as to be changed.

By changing the rotation speed, the compensation voltage and the interference voltage constituting _{the command value v d of the d-axis voltage change. As a result, it is possible to prevent the command value v d} of the d-axis voltage from taking a value close to 0 even though there is a deviation in the magnetic pole position. As a result, the correction value of the magnetic pole position is learned with higher accuracy.

Further, when the command value v _d of the d-axis voltage is smaller than the preset threshold value when the operation mode is the learning operation mode, the current command generation unit 7 sets the rotation direction of the permanent magnet synchronous machine in the learning operation mode. _{The command value i q} ^* of the q-axis current is generated so as to be changed.

When a load is connected to the motor 2, the magnitude of the current value of the motor 2 may depend on the rotation direction. When the current value of the motor 2 changes, _{the magnitude of the command value v d} of the d-axis voltage also changes. _{Therefore, it is avoided that the command value v d} of the d-axis voltage takes a value close to 0 even though the magnetic pole position is deviated. As a result, the correction value of the magnetic pole position is learned with higher accuracy.

Further, the operation mode setting unit 17 sets the operation mode to the learning operation mode when the power supply is started.

As a result, even when the mounting state of the electric motor 2 and the rotation angle detector 4 is changed while the power supply is cut off, the control device 1 can be operated with the electric motor 2 and the rotation angle detector 4 by learning operation. It is possible to obtain a correction value corresponding to the mounting state of.

The control device 1 may improve the accuracy of _{the third correction phase Δθ 3} by changing both the rotation speed and the rotation direction of the electric motor 2 in the learning operation.

Embodiment 3.
In the third embodiment, the differences from the examples disclosed in the first embodiment and the second embodiment will be described in detail. As for the features not described in the second embodiment, any of the features of the examples disclosed in the first embodiment and the second embodiment may be adopted.

There is a possibility that the magnetic pole positions may shift in normal operation due to changes over time in the motor 2. At this time, the control performance of the motor 2 by the control device 1 may deteriorate or the motor 2 may become unstable. Therefore, the control device 1 determines the deviation of the magnetic pole position by monitoring the value of the q-axis current. Here, the q-axis current is a current value corresponding to the torque of the motor 2. The control device 1 switches the operation mode of the electric motor 2 to the learning operation mode when determining the deviation of the magnetic pole position.

An example of the operation of the control device 1 will be described with reference to FIG.
FIG. 9 is a flowchart showing an example of the operation of the control device according to the third embodiment in the normal operation.

In step S91, the control device 1 determines whether the value of the q-axis current is equal to or less than a preset threshold value. The determination is made, for example, by the operation mode setting unit 17. Here, the threshold value is set based on the torque required in the normal operation estimated in advance when the operation pattern or the load of the motor 2 in the normal operation is determined, for example. Alternatively, the threshold value may be set based on the rated torque of the motor 2. When the determination result for the value of the q-axis current is No, the operation of the control device 1 proceeds to step S92. When the determination result is Yes, the operation mode setting unit 17 continuously sets the operation mode to the normal operation mode. After that, the operation of the control device 1 proceeds to step S91 again.

In step S92, the operation mode setting unit 17 switches the operation mode of the motor 2 to the learning operation mode. After that, the operation of the control device 1 proceeds to step S91.

As described above, in the control device 1 according to the third embodiment, when the command value or the actual value of the q-axis current exceeds a preset threshold value when the operation mode is the normal operation mode, the operation mode The setting unit 17 sets the operation mode to the learning operation mode.

When the magnetic pole position is deviated, the current controlled to flow in the q-axis also flows in the d-axis. Therefore, the q-axis current required to generate the commanded torque increases. Therefore, by monitoring the q-axis current, the deviation of the magnetic pole position can be determined. When it is determined that the magnetic pole positions are deviated, the operation mode setting unit 17 sets the operation mode to the learning operation mode. As a result, the control device 1 can prevent the motor 2 from being operated while the magnetic pole positions are displaced. The control device 1 can stably drive the electric motor 2.

The value of the q-axis current may suddenly exceed the threshold value regardless of the deviation of the magnetic pole position. Therefore, the operation mode setting unit 17 may set the operation mode to the learning operation mode when the command value or the actual value of the q-axis current exceeds a preset threshold value a plurality of times. Alternatively, the operation mode setting unit 17 sets the operation mode to the learning operation mode when the command value or the actual value of the q-axis current continuously exceeds the preset threshold value for a predetermined time. May be good.

Further, the control device 1 may include a notification unit. The notification unit is a part that notifies information such as a warning to a person who manages the electric motor 2, for example. For example, when it is not possible to shift to the learning operation mode due to the load state of the motor 2, the notification unit notifies a warning to stop the operation of the motor 2.

The control device according to the present invention can be applied to control a permanent magnet synchronous machine.

1 Control device, 2 Motor, 3 Current detector, 4 Rotation angle detector, 5 Phase calculation unit, 6 Speed calculation unit, 7 Current command generation unit, 8 Current control unit, 9 1st correction phase calculation unit, 10 2nd Correction phase calculation unit, 11 coordinate conversion unit, 12 power converter, 13 3-phase / 2-axis conversion unit, 14 2-axis / 3-phase conversion unit, 15 gain amplifier, 16 integrator, 17 operation mode setting unit, 18 storage unit

Claims (10)

A current command generator that generates command values for the d-axis current and q-axis current of the permanent magnet synchronous machine,
A current control unit that calculates the command values of the d-axis voltage and the q-axis voltage of the permanent magnet synchronous machine by using the command value generated by the current command generation unit as an input.
A first correction phase calculation unit that calculates the first correction phase based on the command value of the d-axis voltage calculated by the current control unit, and a first correction phase calculation unit.
The second correction phase is calculated based on at least one of the command value of the q-axis current calculated by the current control unit or the actual value of the q-axis current of the permanent magnet synchronous machine and the parameters of the permanent magnet synchronous machine. Correction phase calculation unit and
A conversion that performs coordinate conversion on the dq coordinate in the current control unit using the electric angle of the permanent magnet synchronous machine corrected by the third correction phase, which is the sum of the first correction phase and the second correction phase. Department and
A control device for a permanent magnet synchronous machine. The first correction phase calculation unit includes a compensation voltage calculated based on the deviation between the command value and the actual value of the d-axis current, and a non-interference voltage that deinterferes voltage interference between the d-axis and the q-axis. The control device for a permanent magnet synchronous machine according to claim 1, wherein the first correction phase is calculated based on a command value of a d-axis voltage which is the sum of. The control device for a permanent magnet synchronous machine according to claim 1 or 2, wherein the first correction phase calculation unit calculates the first correction phase by multiplying a command value of a d-axis voltage by a constant and integrating. The permanent magnet synchronization according to any one of claims 1 to 3, wherein the second correction phase calculation unit calculates the second correction phase using the inductance and the induced voltage constant of the permanent magnet synchronous machine as the parameters. Machine control device. It is provided with an operation mode setting unit having a storage unit for setting the operation mode of the permanent magnet synchronous machine and storing the third correction phase calculated when the operation mode is the learning operation mode.
Claims 1 to claim 1 to claim that the conversion unit performs coordinate conversion using the electric angle corrected by the third correction phase stored in the storage unit when the operation mode is the normal operation mode. The control device for the permanent magnet synchronous machine according to any one of 4. When the operation mode is the learning operation mode, the current command generation unit sets the command value of the d-axis current to 0, and sets the q-axis current so that the rotation speed of the permanent magnet synchronous machine becomes constant. The control device for a permanent magnet synchronous machine according to claim 5, which generates a command value. When the command value of the d-axis voltage is smaller than a preset threshold value when the operation mode is the learning operation mode, the current command generation unit determines the rotation speed of the permanent magnet synchronous machine in the learning operation mode. The control device for a permanent magnet synchronous machine according to claim 5 or 6, which generates a command value of a q-axis current so as to be changed. When the command value of the d-axis voltage is smaller than a preset threshold value when the operation mode is the learning operation mode, the current command generation unit determines the rotation direction of the permanent magnet synchronous machine in the learning operation mode. The control device for a permanent magnet synchronous machine according to any one of claims 5 to 7, which generates a command value of a q-axis current so as to be changed. The operation mode setting unit sets the operation mode to the learning operation mode when the command value or the actual value of the q-axis current exceeds a preset threshold value when the operation mode is the normal operation mode. The control device for a permanent magnet synchronous machine according to any one of claims 5 to 8. The control device for a permanent magnet synchronous machine according to any one of claims 5 to 9, wherein the operation mode setting unit sets the operation mode to the learning operation mode when the power supply is started.

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