JP6827358B2 - Motor test equipment - Google Patents

Description

The present invention relates to a motor test device.

In the evaluation of the performance of the test motor (for example, maximum torque and efficiency), each parameter may be measured after attaching a position / speed sensor to the test motor.

When the position sensor is attached to the test motor, the magnetic pole position and speed of the rotor can be obtained directly, so even if there is an error in the motor resistance value, the current can be minimized with the same torque. Can be done.

However, there are cases where the performance of the test motor to which the position sensor cannot be attached is evaluated. In the position sensorless control executed for such a motor, the axis error, which is the deviation between the rotation phase command value and the rotation phase value of the PM motor, is estimated and calculated using the motor parameters.

In position sensorless control, if the d-axis current, which is the exciting component current, is generated at a value other than zero, it becomes difficult to minimize the current with the same torque when there is an error in the resistance. On the other hand, in the technique of Patent Document 1, for example, the current can be minimized at the same torque by using the inductance value calculated from the q-axis current detection value.

Japanese Unexamined Patent Publication No. 2008-11631

In the technique of Patent Document 1, it is possible to operate the motor with high efficiency even if an error occurs in the resistance, but the inductance and the like, which are motor parameters, are not a little used in the calculation. Therefore, there is a problem that it cannot be applied to a test motor whose parameters such as inductance and magnetic flux are unknown. Here, it is possible to automatically measure the parameters of the test motor, but it is necessary to make corrections in consideration of the measurement error and the parameter changes due to current and temperature. Therefore, a system that performs automatic measurement generally requires a complicated control system, which causes another problem such as cost.

An object of the present invention made in view of such circumstances is to provide a motor test device capable of operating a test motor having unknown parameters such as inductance and magnetic flux with high efficiency. is there.

In order to solve the above-mentioned problems, the motor test device according to the embodiment of the present invention detects the actual torque of the test motor detected by the torque meter and the speed sensor attached to the dynamo connected to the torque meter. A motor test device that receives the speed of the test motor and the torque command for operating the test motor and executes the performance evaluation test of the test motor, and issues a voltage command based on the torque command. A phase adjustment command is generated based on the generated current controller and the torque command and the actual torque, and an offset is added to the first phase obtained by integrating the speed according to the phase adjustment command to generate a second phase. Power to output a phase controller, a second coordinate converter that generates an AC signal based on the second phase and the voltage command, and a signal for operating the test motor based on the AC signal. A converter and a first coordinate converter that converts a three-phase current from the power converter into a current of the γδ axis output to the current controller are provided.
The phase controller is 90 ° or more and 180 ° or less with respect to the phase controller when the magnitude of the actual torque is zero or the directions of the torque command and the actual torque are opposite on the q-axis. A phase adjustment command is generated to make the first adjustment to generate a second phase by adding an offset of the magnitude of.

Further, in the motor test apparatus according to the embodiment of the present invention, the phase controller executes at least one of the first correction process and the second correction process after the first adjustment, and the first correction process is performed. The correction process of 1 stores the first actual torque detected at the first time and adds a positive offset of less than 90 ° to the first phase to generate the second phase. , The process of receiving the second actual torque detected at the second time after the first time, and the second correction process stores the third actual torque detected at the third time. , A negative offset of less than 90 ° is added to the first phase to generate the second phase, and the fourth actual torque detected at the fourth time after the third time. a process to receive, when executing the first correction processing, if Kere smaller than the first actual torque is the second real torque, repeating the first correction processing, the first If the actual torque is equal to or greater than the second actual torque, the second correction process is executed, and when the second correction process is executed, the third actual torque is higher than the fourth actual torque. If the value is small, the second correction process may be repeated, and if the third actual torque is equal to or greater than the fourth actual torque, the first correction process may be executed.

According to the embodiment of the present invention, it is possible to provide a motor test device capable of operating the test motor with high efficiency even if the test motor has unknown parameters such as inductance and magnetic flux.

It is a figure which illustrates the structure of the system which uses the test apparatus of the motor which concerns on one Embodiment of this invention. It is a figure for demonstrating the control shaft used by the test apparatus of the motor which concerns on one Embodiment of this invention. 3 (a) to 3 (c) are diagrams for explaining the behavior of the control axis of FIG. It is a flowchart which shows the control method of the test apparatus of the motor which concerns on one Embodiment of this invention. It is a figure which illustrates the structure of the system which uses the test apparatus of the motor of the comparative example.

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

(System using motor test equipment)
FIG. 1 is a diagram illustrating a configuration of a system using the motor test device 9 according to the present embodiment. The system of FIG. 1 includes a test motor 1, a torque meter 2, a dynamo 3, a speed sensor 4, a dynamo inverter 8 and a wattmeter 10 in addition to the test device 9 according to the present embodiment.

The test motor 1 is a motor to be tested whose performance (for example, maximum torque and efficiency) is evaluated by the test device 9. Here, in the system using the test apparatus 9 according to the present embodiment, the torque meter 2, the dynamo 3, the speed sensor 4, the dynamo inverter 8 and the wattmeter 10 other than the test motor 1 are placed at predetermined locations (for example, a test site or the like). ) Is preset.

The torque meter 2 is connected to the test motor 1 and outputs the detected output torque (actual torque) of the test motor 1 to the test device 9. The torque meter 2 may be, for example, a flange type, but the torque meter 2 is not limited to this.

The dynamo 3 is a generator that generates electricity according to the rotation of the shaft. In the test for evaluating the performance of the test motor 1, the dynamo 3 is used as a load machine of the test motor 1. In the system shown in FIG. 1, the shaft of the dynamo 3 is connected to the shaft of the torque meter 2. Therefore, the rotation of the test motor 1 is transmitted to the dynamo 3.

The speed sensor 4 is a speed measuring instrument attached to the dynamo 3. The speed of the dynamo 3 detected by the speed sensor 4 (for example, it may be a rotation speed) is output to the dynamo inverter 8 and the test device 9. Here, since the shaft of the dynamo 3 is connected to the shaft of the torque meter 2, the speed of the dynamo 3 represents the speed of the test motor 1. That is, even in the performance evaluation of the test motor 1 to which the position / speed sensor is not attached, the test device 9 can directly grasp the speed of the test motor 1.

The dynamo inverter 8 adjusts the operation of the dynamo 3 which is the load machine of the test motor 1 based on the speed command ω ^* and the speed from the speed sensor 4. In the system shown in FIG. 1, the dynamo inverter 8 can output a speed command ω ^* to the dynamo 3 to operate the dynamo 3 at an arbitrary speed. Here, the speed command ω ^* is set according to the test content of the test motor 1. The speed command ω ^* may be output from the test device 9.

The power meter 10 measures the power required to operate the test motor 1 during the performance evaluation test. In the system shown in FIG. 1, it is determined whether the test motor 1 is operating efficiently (for example, whether the current is the minimum and the actual torque is the maximum) based on the measurement result including the electric power detected by the power meter 10. Will be done.

The test device 9 receives the actual torque from the torque meter 2 and the speed from the speed sensor 4. Further, the test apparatus 9 receives the excitation component current command iγ ^* and the torque component current command iδ ^* from, for example, the apparatus that manages the system shown in FIG. The test device 9 generates a three-phase AC signal and outputs it to the test motor 1 in order to operate the test motor 1 under the conditions according to the test.

The test device 9 includes a current detector 6, a power converter 7, and a control unit 20.

The current detector 6 detects the current flowing through the test motor 1. In the present embodiment, the current detector 6 detects the current of each phase of the three-phase AC signal output to the test motor 1. The current detector 6 outputs the detected current value to the control unit 20. The current detector 6 may be provided inside the power converter 7.

The power converter 7 converts the AC signal obtained by the coordinate conversion into an appropriate signal for operating the test motor 1 and outputs the signal. For example, when the test motor 1 is a three-phase AC motor, the power converter 7 may be a three-phase PWM inverter having a known configuration.

The control unit 20 executes operations such as coordinate conversion, current control, and phase control. The control unit 20 includes an integrator 11, a phase controller 12, a current controller 13, a first coordinate converter 14, and a second coordinate converter 15.

The integrator 11 receives the speed of the dynamo 3 from the speed sensor 4, that is, the speed of the test motor 1. The integrator 11 integrates the speed of the test motor 1 to generate a phase θ'(first phase).

The phase controller 12 receives the actual torque from the torque meter 2, the phase θ'from the integrator 11, and the torque component current command iδ ^* from the current controller 13. The phase controller 12 adjusts the phase θ'in response to the phase adjustment command to generate the phase θ (second phase).

The first coordinate converter 14 receives the phase θ from the phase controller 12 and the current value from the current detector 6. The first coordinate converter 14 performs coordinate conversion using the current values of the phase θ and the three-phase AC signal, and generates two DC signals. That is, the first coordinate converter 14 converts the three-phase current (the current of the three-phase AC signal) into three-phase to two-phase, and converts the current from the stationary coordinates to the rotating coordinates to convert the current on the γδ axis. The γδ axis (γδ coordinates) will be described later.

The second coordinate converter 15 receives the phase θ from the phase controller 12 and the voltage command from the current controller 13. The second coordinate converter 15 performs coordinate conversion using the phase θ and the voltage command, and generates three AC signals. That is, the second coordinate converter 15 executes the reverse conversion of the first coordinate converter 14 and converts the voltage command of the γδ coordinate into a three-phase stationary coordinate system. The generated AC signal is output to the power converter 7.

The current controller 13 receives a current command (excitation component current command iγ ^* and torque component current command iδ ^* ) and two DC signals generated by the first coordinate converter 14. The current controller 13 generates a voltage command based on the current command and the two DC signals. The current controller 13 outputs the torque component current command iδ ^* to the phase controller 12. Further, the current controller 13 outputs the generated voltage command to the second coordinate converter 15. In the present embodiment, the current controller 13 compares the current command with the two DC signals and generates a voltage command by proportionally and integratingly controlling the difference.

(Control axis of motor test device)
FIG. 2 is an analysis model diagram of the test motor 1. The permanent magnet 16 represents the rotor of the motor.

In a rotating coordinate system that rotates at the same speed as the magnetic flux created by the permanent magnet 16, the direction of the magnetic flux created by the permanent magnet 16 is defined as the d-axis. Here, the control estimation axis that controls the test motor 1 by estimating that the test device 9 is the d-axis is defined as the γ-axis. Further, the q-axis is taken in the phase advanced by 90 degrees by the electric angle from the d-axis. Further, the δ axis is taken in the phase advanced by 90 degrees by the electric angle from the γ axis. The δ axis is a control estimation axis that controls the test motor 1 by presuming that the motor test device 9 is the q axis.

The coordinate axis of the rotating coordinate system having the d-axis and the q-axis as the coordinate axes is called the dq-axis. The current flowing in the d-axis direction is called the exciting component current. Further, the current flowing in the q-axis direction is called a torque component current. The controlled rotating coordinate system used by the test apparatus 9 is a coordinate system in which the γ axis and the δ axis are selected as the coordinate axes. The coordinate axis of the rotating coordinate system having the γ axis and the δ axis as the coordinate axes is called the γδ axis.

When the performance evaluation test is executed for the test motor 1 for the first time, the magnetic pole position of the test motor 1 is unknown. The test device 9 controls the test motor 1 with reference to the γδ axis whose axis is deviated by an angle β from the actual dq axis of the test motor 1.

The test device 9 adjusts so that the actual torque is as large as possible in order to operate the test motor 1 with high efficiency. For example, FIG. 3A shows the relationship between the dq axis and the γδ axis when the test motor 1 is operating with high efficiency. At this time, the angle β approaches 0, and the control γδ axis substantially overlaps with the actual dq axis of the test motor 1. The test apparatus 9 adjusts the phase θ output by the phase controller 12 by changing the phase adjustment command so that the relationship as shown in FIG. 3A can be obtained.

In the system shown in FIG. 1, the phase θ is adjusted as follows, for example. First, the dynamo 3 is rotated at a constant speed. Then, as a current command for the test motor 1, a torque component current command iδ ^* is given to the current controller 13 with an arbitrary magnitude while setting the exciting component current command iγ ^* to zero.

Here, an arbitrary torque component current command iδ ^* is set at the start of the performance evaluation test of the test motor 1, but at this time, the relationship between the dq axis and the γδ axis (the magnitude of the angle β) is unknown. However, since the test device 9 receives the actual torque, the relationship can be estimated from the magnitude of the actual torque.

As shown in FIG. 3B, when the angle β satisfies the condition of β> 90 ° or β <−90 °, the direction of the torque component current iδ in control and the direction of the actual current iq are opposite to each other. Become. At this time, the direction of the actual torque is opposite to the torque command (torque component current command iδ ^* ).

The test device 9 adds an offset of more than 90 ° to 180 ° or less or −180 ° or more and less than −90 ° to the phase θ ′ in the phase controller 12 when the direction of the actual torque is opposite to the torque command. To generate the phase θ. When the phase controller 12 adds an offset to generate the phase θ, the relationship between the dq axis and the γδ axis approaches the relationship shown in FIGS. 3 (b) to 3 (a).

Further, as shown in FIG. 3C, when the angle β satisfies the condition of β = 90 ° or β = −90 °, the direction of the torque component current iδ in control becomes the same direction as the d-axis. At this time, no torque is generated. Therefore, the magnitude of the actual torque becomes zero.

When the magnitude of the actual torque is zero, the test device 9 adds an offset of 90 ° or −90 ° to the phase θ ′ in the phase controller 12 to generate the phase θ. When the phase controller 12 adds an offset to generate the phase θ, the relationship between the dq axis and the γδ axis approaches the relationship shown in FIGS. 3 (c) to 3 (a).

Here, the phase controller 12 changes the offset based on the phase adjustment command. The phase controller 12 generates a phase adjustment command based on the torque component current command iδ ^* received via the current controller 13 and the actual torque. More specifically, if the magnitude of the actual torque is zero, the phase controller 12 generates a phase adjustment command so as to add an offset of a magnitude of 90 ° to the phase θ'. Further, the phase controller 12 has a phase θ'from 90 ° when the magnitude of the actual torque is not zero and the directions of the torque component current command iδ ^* and the actual torque are opposite to each other on the q-axis. A phase adjustment command is generated so as to add a large offset of 180 ° or less. Here, the adjustment for generating the phase θ by adding an offset having a magnitude of 90 ° or more and 180 ° or less in the phase controller 12 as described above is defined as the first adjustment.

The test device 9 has a magnitude of less than 90 ° in the phase controller 12 after the first adjustment (when the actual torque is non-zero and the directions of the actual torque and the torque command are not opposite on the q-axis). The second adjustment to generate the phase θ by adding the torque is repeated. The actual torque can be maximized by performing the second adjustment.

FIG. 4 is a flowchart showing an example of a process (control method) executed by the test apparatus 9 according to the present embodiment.

The test device 9 confirms that the dynamo 3 is rotating (step S1). In this embodiment, it is preferable to rotate the dynamo 3 at a constant speed.

The current controller 13 of the test device 9 receives the current command of the test motor 1 (step S2). In the present embodiment, the current commands are the excitation component current command iγ ^* and the torque component current command iδ ^* according to the performance evaluation test of the test motor 1.

The phase controller 12 of the test device 9 generates a phase adjustment command based on the torque component current command iδ ^* and the actual torque. As described above, the phase controller 12 receives the output torque (actual torque) of the test motor 1 detected by the torque meter 2. The phase controller 12 of the test apparatus 9 generates a phase adjustment command for generating the phase θ by adding an offset of 90 ° to the phase θ'when the actual torque is zero (Yes in step S3). To do. Here, the size of the offset is not limited to 90 ° and may be approximately 90 °. Then, the phase controller 12 of the test apparatus 9 changes the phase θ by nearly 90 ° according to the phase adjustment command (step S4). After that, the test apparatus 9 returns to the process of step S3.

The phase controller 12 of the test apparatus 9 executes the process of step S5 when the actual torque is non-zero (No in step S3). The process of step S5 is to determine whether the direction of the actual torque is opposite to the torque command. In this example, it is assumed that the sign of the torque according to the torque command is positive.

When the sign of the actual torque is negative (Yes in step S5), the phase controller 12 of the test apparatus 9 adds an offset of 90 ° or more and 180 ° or less to the phase θ'to generate the phase θ. Generate a phase adjustment command for. For example, the magnitude of the offset may be set to approximately 180 °. Then, the phase controller 12 of the test apparatus 9 changes the phase θ by nearly 180 ° according to the phase adjustment command (step S6). After that, the test apparatus 9 returns to the process of step S5.

The phase controller 12 of the test device 9 proceeds to the process of step S7 when the sign of the actual torque is not negative (No in step S5). Here, the processes from step S3 to step S6 correspond to the first adjustment executed by the test apparatus 9 according to the present embodiment.

After the first adjustment, the test apparatus 9 executes the processes from step S7 to step S14 corresponding to the second adjustment. In this embodiment, the second adjustment is repeatedly executed.

The phase controller 12 of the test device 9 receives the first actual torque detected by the torque meter 2 at the time T0 (first time) and stores it as the actual torque 0 (step S7).

The phase controller 12 of the test apparatus 9 adds a positive offset of less than 90 ° to the phase θ'to generate a phase adjustment command for generating the phase θ. The phase controller 12 of the test apparatus 9 corrects the phase θ to the plus side according to the phase adjustment command (step S8).

The phase controller 12 of the test device 9 receives the second actual torque detected by the torque meter 2 at the time T1 (second time) after the time T0, and acquires it as the actual torque 1 (step S9). Here, the processes from step S7 to step S9 correspond to the first modification process executed by the test apparatus 9 according to the present embodiment.

The phase controller 12 of the test device 9 compares the actual torque 1 with the actual torque 0. If the actual torque 0 is less than actual torque 1 (Yes in step S10), and the test apparatus 9 is returned to the processing in step S7.

If the actual torque 0 Zone smaller than actual torque 1 (No in step S10), and the test apparatus 9 proceeds to step S11.

The phase controller 12 of the test device 9 receives the third actual torque detected by the torque meter 2 at the time T3 (third time) and stores it as the actual torque 0 (step S11).

The phase controller 12 of the test apparatus 9 adds a negative offset of less than 90 ° to the phase θ'to generate a phase adjustment command for generating the phase θ. The phase controller 12 of the test apparatus 9 corrects the phase θ to the minus side according to the phase adjustment command (step S12).

The phase controller 12 of the test device 9 receives the fourth actual torque detected by the torque meter 2 at the time T4 (fourth time) after the time T3, and acquires it as the actual torque 1 (step S13). Here, the processes from step S11 to step S13 correspond to the second modification process executed by the test apparatus 9 according to the present embodiment.

The phase controller 12 of the test device 9 compares the actual torque 1 with the actual torque 0. When the actual torque 0 is smaller than the actual torque 1 (Yes in step S14), the test apparatus 9 returns to the process of step S11.

When the actual torque 0 is not smaller than the actual torque 1 (No in step S14), the test apparatus 9 returns to the process of step S7.

(Comparison example)
Here, with reference to FIG. 5, the effect of the motor test device 9 of the present embodiment will be described while showing the motor test device 9A of the comparative example.

FIG. 5 is a configuration diagram of a system using the motor test device 9A of the comparative example. The system of FIG. 5 does not include a torque meter 2, a dynamo 3, a speed sensor 4, a dynamo inverter 8 and a power meter 10. Further, the test device 9A includes a control unit 20A instead of the control unit 20 included in the test device 9 of the present embodiment. The control unit 20A does not include the integrator 11 and the phase controller 12, but instead includes a virtual inductance calculation unit 21 and a phase estimator 22. Others are the same as in FIG. 1, and detailed description thereof will be omitted.

The phase estimator 22 estimates the axis error based on the d-axis and q-axis voltage command values Vdc ^* , Vqc ^* , frequency calculation value ω1, current detection value idc, iqc, inductance calculation value L ^*, and motor constant. To do. Then, the phase estimator 22 outputs the frequency calculation value ω1 so as to match the command value of the axis error, and outputs the rotation phase command value θc ^* obtained by integrating the frequency calculation value ω1.

Further, the virtual inductance calculation unit 21 outputs the inductance calculation value L ^* used in the phase estimator 22 and the current controller 13 from the current detection value iqc on the q-axis.

In the system using the motor test device 9A of the comparative example, the resistance value and the inductance value, which are the motor parameters, are not a little used in the calculation. Therefore, it is difficult to apply the test motor 1 whose parameters are unknown.

On the other hand, the motor test device 9 according to the present embodiment can perform the test motor 1 with high efficiency by the above-mentioned first adjustment without executing the calculation using the resistance value and the inductance value which are the motor parameters. Allows you to drive. Further, the motor test device 9 according to the present embodiment makes it possible to operate the test motor 1 with higher efficiency by further adjusting the second adjustment.

Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications and modifications based on the present disclosure. Therefore, it should be noted that these modifications and modifications are within the scope of the present invention.

For example, in this embodiment, the speed sensor 4 is attached to a dynamo 3 connected to the torque meter 2. However, the speed sensor 4 may be attached to the torque meter 2.

1 Test motor 2 Torque meter 3 Dynamo 4 Speed sensor 6 Current detector 7 Power converter 8 Dynamo inverter 9,9A Test device 11 Integrator 12 Phase controller 13 Current controller 14 First coordinate converter 15 Second Coordinate converter 16 Permanent magnet 20, 20A Control unit 21 Virtual inductance calculation unit 22 Phase estimator

Claims (2)

Receives the actual torque of the test motor detected by the torque meter, the speed of the test motor detected by the speed sensor attached to the dynamo connected to the torque meter, and the torque command to operate the test motor. This is a motor test device that executes the performance evaluation test of the test motor.
A current controller that generates a voltage command based on the torque command,
A phase controller that generates a phase adjustment command based on the torque command and the actual torque, and adds an offset to the first phase in which the speed is integrated to generate a second phase according to the phase adjustment command.
A second coordinate converter that generates an AC signal based on the second phase and the voltage command, and
A power converter that outputs a signal for operating the test motor based on the AC signal, and
A first coordinate converter that converts a three-phase current from the power converter into a γδ-axis current output to the current controller is provided.
The phase controller is 90 ° or more and 180 ° or less with respect to the phase controller when the magnitude of the actual torque is zero or the directions of the torque command and the actual torque are opposite on the q-axis. A motor test device that generates a phase adjustment command that causes a first adjustment to generate a second phase by adding an offset of the magnitude of. The phase controller
After the first adjustment, at least one of the first correction process and the second correction process is executed.
The first correction process is
The first actual torque detected at the first time is stored, and a positive offset having a magnitude of less than 90 ° is added to the first phase to generate the second phase to generate the second phase. It is a process of receiving the second actual torque detected at the second time after that.
The second correction process is
The third actual torque detected at the third time is stored, and a negative offset of less than 90 ° is added to the first phase to generate the second phase to generate the second phase. This is the process of receiving the fourth actual torque detected at the fourth time after that.
When the first correction process is executed,
If Kere smaller than the first actual torque actual torque is the second of the repeats the first correction processing,
If the first actual torque is equal to or greater than the second actual torque, the second correction process is executed.
When the second correction process is executed,
If the third actual torque is smaller than the fourth actual torque, the second correction process is repeated.
The motor test device according to claim 1, wherein if the third actual torque is equal to or greater than the fourth actual torque, the first correction process is executed.

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