A method for testing the load capacity of a high-speed permanent magnet synchronous motor controller

Abstract

A method for testing the load capacity of a high-speed permanent magnet synchronous motor controller is disclosed. The controller employs a dual-loop vector control method with speed and current, and the dual-loop control uses an inverse calculation anti-saturation method to prevent integral saturation and large overshoot. The testing method includes the following steps: S1, determining the technical specifications corresponding to the controller's rated operating point based on the motor's key electrical indicators; S2, setting a reference speed for the motor based on the test frequency; S3, setting the saturation value of the PI controller output based on the rated operating point to prevent overcurrent during the test; S4, calculating the PI parameters for the speed loop and current loop; S5, setting the target current value for the test; and S6, running the motor to the set speed, and increasing the reactive current I after the motor stabilizes. d This invention enables testing the controller's load capacity without relying on a dedicated platform, allowing for rapid assessment of controller performance and facilitating fast iteration in controller development.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology, specifically relating to a method for testing the load capacity of a high-speed permanent magnet synchronous motor controller. Background Technology

[0002] High-speed permanent magnet synchronous motors have many advantages, such as high power density, fast dynamic response, and low loss, and are widely used in new energy electric vehicles, aerospace, and other fields. As motor speed increases and operating conditions become more complex, the requirements for controllers are also becoming more stringent.

[0003] Key technical specifications of motor controllers include output voltage, output current, and output frequency. During the controller prototype design phase, it is crucial to rapidly test these key electrical parameters and assess their design compliance. This necessitates testing the controller's load capacity. Traditional testing methods involve mounting the motor on a dedicated motor load testing platform. However, this platform is incompatible with the testing requirements of different controllers and motors, failing to meet the demands of rapid controller development iterations. Furthermore, as motor speeds increase, the cost of building a dedicated test bench significantly rises due to limitations imposed by bearings and other factors.

[0004] Chinese patent CN108695961A discloses a system for testing drive motor controllers. This patent uses a supercapacitor as the input to the drive motor controller, and the controller's three-phase voltage output is rectified and then connected to a load for testing the drive motor controller's performance. This patent simplifies load testing and saves on tooling costs required when installing different motors on a towing platform. However, this patent still has the following drawbacks:

[0005] 1. The condition for this patent to determine that the drive motor controller has good performance is that the controller input power and the controller output three-phase voltage after rectification are the same. This condition ignores the controller efficiency and motor efficiency.

[0006] 2. The drive motor controller test system described in this patent still requires a high cost to build a load device, and does not meet the requirements of rapid iteration in controller development during testing.

[0007] Chinese patent CN114115182A discloses a motor controller testing system and method. The motor controller described in this patent uses a position sensor for control, and its performance is tested based on the simulated resolver signal. While the testing method described in this patent improves the accuracy of rotor position testing, the patent still has the following drawbacks:

[0008] 1. The motor controller testing method described in this patent only provides no-load testing of the motor controller, without performing load testing, and does not determine the load-bearing performance of the motor controller;

[0009] 2. The controller control method mentioned in the motor controller test method described in this patent is vector control with position sensor, which is not applicable to control without position vector.

[0010] Therefore, this invention proposes a load capacity testing method for high-speed permanent magnet synchronous motor controllers to solve the problems of difficult and costly load capacity testing of high-speed permanent magnet synchronous motor controllers; it meets the requirements of rapid iteration in controller development and is applicable to load performance testing of controllers based on sensor-based vector control methods and sensorless vector control methods. Summary of the Invention

[0011] To address the aforementioned technical problems, this invention provides a method for testing the load capacity of a high-speed permanent magnet synchronous motor controller. First, vector control of the permanent magnet synchronous motor is implemented, and the PI control loop and current loop are adjusted using an inverse calculation anti-saturation method to ensure stable motor operation at the test point. Then, based on vector control, current is injected into the motor's d-axis to bring the controller's output current to its rated value, and the motor speed is adjusted to bring the controller's output voltage to its rated value.

[0012] The present invention is achieved through the following technical solutions.

[0013] This invention provides a method for testing the load capacity of a high-speed permanent magnet synchronous motor controller, comprising the following steps:

[0014] Step S1. Determine the electrical parameters of the controller based on the electrical parameters of the motor at its rated operating point, including rated speed and effective value of phase current;

[0015] Step S2. Calculate the rated speed based on the motor's rated frequency and number of pole pairs, and give the motor a reference speed based on the test operating point;

[0016] Step S3. Set the PI controller output saturation value and the integral saturation coefficient according to the effective value of the phase current during motor test conditions;

[0017] Step S4. Calculate the parameters of the inner current loop PI controller based on the motor electrical parameters and the controller control cycle, and adjust the parameters of the speed loop PI controller.

[0018] Step S5. Set the target current value for testing;

[0019] Step S6. Run the motor to the set speed. After the motor is running stably, increase the reactive current I. d Test the controller's load capacity.

[0020] Furthermore, in step S6, the high-speed permanent magnet synchronous motor is controlled by a dual closed-loop vector control of speed and current to run the motor to the set speed. The control system includes an A / D sampling module, a resolver decoding module, a PI controller, and an SVPWM module.

[0021] Furthermore, the step S6, which employs dual closed-loop vector control of speed and current to control the high-speed permanent magnet synchronous motor, specifically includes the following steps:

[0022] Step S61. Obtain the two-phase current i of the high-speed permanent magnet synchronous motor through the A / D sampling module. a and i b i a and i b The two-phase current i in the synchronous rotating coordinate system is obtained after coordinate transformation. d and i q ;

[0023] Step S62. Obtain the motor rotor position θ through the rotary transformer decoding module. e The q-axis current is obtained by subtracting the given motor speed from the feedback motor speed, along with the speed n.

[0024] Step S63. and the i obtained in step 61 q After subtraction, the q-axis voltage u is obtained through a q-axis current PI controller. q ;

[0025] Step S64. D-axis given current After slope treatment, it is related to the d-axis current i d The difference is used to obtain the d-axis voltage u after passing through the d-axis current PI controller. d ;

[0026] Step S65.u d and u q After coordinate transformation, the voltage u in the α and β coordinate systems is obtained. α and u β ;

[0027] Step S66.u α and u β After modulation by the SVPWM module, six PWM signals are generated to control the three-phase inverter and drive the high-speed permanent magnet synchronous motor.

[0028] Furthermore, in step S62, the PI controller applies an inverse calculation anti-saturation method to process the signal, including the following steps:

[0029] Step S621. The difference between the reference value and the feedback value is used as the input of the proportional circuit, and the proportional term Up is output after calculation.

[0030] Step S622. Use the proportional output term Up as the input to the integral stage, and apply the inverse calculation anti-saturation method. In the output limiting section, use the difference between the input signal (OutPreSat) and the output signal (Out) as the feedback input to the integral stage.

[0031] Step S623. Adjust the saturation coefficient to control the integral regulation desaturation capability and prevent integral saturation and large overshoot.

[0032] Furthermore, in step S64, the PI controller applies an inverse calculation anti-saturation method to process the signal, including the following steps:

[0033] Step S641. The difference between the reference value and the feedback value is used as the input of the proportional circuit, and the proportional term Up is output after calculation.

[0034] Step S642. Use the proportional output term Up as the input to the integral stage, and apply the inverse calculation anti-saturation method. In the output limiting section, use the difference between the input signal (OutPreSat) and the output signal (Out) as the feedback input to the integral stage.

[0035] Step S643. Adjust the saturation coefficient to control the integral regulation desaturation capability and prevent integral saturation and large overshoot.

[0036] Furthermore, in step S61, i a and i b The two-phase current i in the synchronous rotating coordinate system is obtained after coordinate transformation. d and i q The specific transformation formula is as follows:

[0037]

[0038] Furthermore, in step S65, u d and u q After coordinate transformation, the voltage u in the α and β coordinate systems is obtained. α and u β The specific transformation formula is as follows:

[0039]

[0040] Furthermore, in step 5, the target test current value I is set. S Specifically: The controller is set to test the target current based on the motor's rated operating electrical parameters, since the motor's no-load active current I... q Smaller, relative to a given value I d Negligible; according to the formula Ignore active current I qThe given reactive current value is the effective value of the phase current: I s ≈I d Therefore, the target current value I will be tested. S Set as reactive current I d .

[0041] Furthermore, in step S1, the A / D sampling module samples the three-phase current and bus voltage, and performs coordinate transformation on the sampled phase currents to obtain the two-phase current i in the synchronous rotating coordinate system. a and i b .

[0042] The beneficial effects of this invention are as follows: Compared with the prior art, this invention increases the current of the motor under no-load conditions by injecting current into the d-axis of the motor, thereby applying a current load to the controller; and it uses a back-calculation anti-saturation method PI controller to limit the reactive current I. d The output protects the power transistor from breakdown when testing the motor's rated operating point. By increasing the motor's operating speed, a voltage load is applied to the controller. With only slight adjustments to the controller software, the controller load test can be performed without the motor being installed on the drag platform. This greatly reduces the time and economic cost of high-speed motor controller testing and accelerates controller development. Attached Figure Description

[0043] Figure 1 This is a block diagram of the vector control for a permanent magnet synchronous motor.

[0044] Figure 2 Flowchart for load capacity testing of high-speed permanent magnet synchronous motor controller;

[0045] Figure 3 Here is the main interrupt flowchart for the relevant module;

[0046] Figure 4 Here is a block diagram of the inverse calculation anti-saturation method;

[0047] Figure 5 The waveform diagram of the motor phase current under no-load conditions;

[0048] Figure 6 The waveform diagram of the motor phase current under increased current load conditions; Detailed Implementation

[0049] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0050] This invention discloses a method for testing the load capacity of a high-speed permanent magnet synchronous motor controller. It employs dual closed-loop vector control of speed and current to ensure stable motor operation up to a set speed; and utilizes an inverse calculation anti-saturation method PI controller to limit reactive current I. dTo prevent current overshoot, after the motor stabilizes at the test speed, a reactive current output is increased to simulate the three-phase current under controller load, testing the controller's load-carrying capacity. This allows for independent testing of the controller's load capacity without relying on a dedicated platform, enabling rapid performance assessment and facilitating rapid iteration in controller development. The following detailed description of the invention's concept and main principles, in conjunction with the accompanying drawings, will provide a full understanding of its effects and benefits.

[0051] This invention provides a method for testing the load capacity of a high-speed permanent magnet synchronous motor controller, comprising the following steps:

[0052] Step S1. Determine the electrical parameters of the controller based on the electrical parameters of the motor at its rated operating point, including rated speed and effective value of phase current;

[0053] Step S2. Calculate the rated speed based on the motor's rated frequency and number of pole pairs, and give the motor a reference speed based on the test operating point;

[0054] Step S3. Set the PI controller output saturation value and the integral saturation coefficient according to the effective value of the phase current during motor test conditions;

[0055] Step S4. Calculate the parameters of the inner current loop PI controller based on the motor electrical parameters and the controller control cycle, and adjust the parameters of the speed loop PI controller.

[0056] Step S5. Set the target current value for testing;

[0057] Step S6. Run the motor to the set speed. After the motor is running stably, increase the reactive current I. d Test the controller's load capacity.

[0058] like Figure 1 The diagram shown is a vector control block diagram for a permanent magnet synchronous motor. This invention uses this control method to ensure the motor operates stably at a set speed. Specifically, the flowchart of this method's implementation is shown below. Figure 3 As shown, the main interrupt process and related modules.

[0059] The A / D sampling sampled the three-phase current and bus voltage, and the sampled phase current was transformed to obtain the two-phase current in the synchronous rotating coordinate system.

[0060] Specifically, in the interrupt service routine, the resolver decoding function is called to obtain the motor position and speed information through calculation;

[0061] Specifically, the protection module provides overvoltage, overcurrent, and overtemperature protection for the motor and controller, and performs periodic cyclic detection; during controller load capacity testing, it prevents the controller from burning out the power transistors due to overcurrent.

[0062] Specifically, the PI module applies the inverse calculation anti-saturation method to measure the rotational speed, active current Iq, and reactive current I. d Perform PI adjustment to stabilize the output reference value;

[0063] Specifically, the SVPWM module outputs u based on the coordinate changes. α and u β The modulation process generates six PWM signals to control the three-phase inverter and drive the high-speed permanent magnet synchronous motor.

[0064] like Figure 2 The diagram shows a flowchart for testing the load capacity of a high-speed permanent magnet synchronous motor controller. The controller load capacity testing method described in the first aspect of the invention is based on the aforementioned speed-current dual closed-loop vector control system and the inverse calculation anti-saturation method PI controller.

[0065] The specific implementation steps are as follows:

[0066] Step S1: Determine the electrical parameters of the controller based on the electrical parameters of the motor at its rated operating point, such as rated speed and effective value of phase current.

[0067] Step S2: Calculate the rated speed based on the motor's rated frequency and number of pole pairs, and give the motor a reference speed based on the test operating point;

[0068] Step S3: Set the PI controller output saturation value according to the effective value of the phase current during motor test conditions, and set the integral saturation coefficient;

[0069] The larger Kc is, the stronger the integral desaturation effect. Generally, the integral saturation coefficient is equal to the current loop integral coefficient.

[0070] Kc = Ki

[0071] Step S4: Calculate the parameters of the inner current loop PI controller based on the motor electrical parameters and the controller control cycle, and adjust the parameters of the speed loop PI controller.

[0072] Step S5: Set the controller test target current according to the rated operating condition electrical parameters of the motor. Since the active current Iq of the motor is small when it is unloaded, it can be ignored relative to the given value Id.

[0073]

[0074] Ignoring the active current Iq, the measured reactive current value is the effective value of the phase current:

[0075] I s ≈I d ;

[0076] Step S6: Control the motor to the given speed and ensure stable operation; if the motor does not run smoothly, adjust the speed loop PI controller parameters to stabilize the motor; set the target test current value to the reactive current I. d Increase reactive current I d This increases the motor current under no-load conditions, applying a current load to the controller. The d-axis current is set to the motor's rated current to simulate a controller load test and verify the controller's load-carrying capacity.

[0077] The step S6, which employs dual closed-loop vector control of speed and current to control the high-speed permanent magnet synchronous motor, specifically includes the following steps:

[0078] Step S61: Obtain the two-phase current i of the motor through A / D sampling. a and i b i a and i b The two-phase current i in the synchronous rotating coordinate system is obtained after coordinate transformation. d and i q ;

[0079]

[0080] Step S62: Obtain the motor rotor position θ using a rotary transformer. e The q-axis current is obtained by subtracting the given speed n from the motor speed and then passing the result through a speed PI controller.

[0081]

[0082] Step S63: and the i obtained in step 1 q After subtraction, the q-axis voltage u is obtained through a q-axis current PI controller. q ;

[0083] Step S64: d-axis current setting After slope treatment, it is related to the d-axis current i d The difference is used to obtain the d-axis voltage u after passing through the d-axis current PI controller. d ;

[0084]

[0085] Step S65: u d and u q After coordinate transformation, the voltage u in the α and β coordinate systems is obtained. α and u β ;

[0086]

[0087] Step S66: u α and u β After SVPWM modulation, six PWM signals are generated to control the three-phase inverter and drive the high-speed permanent magnet synchronous motor.

[0088] like Figure 4 The diagram shown is a block diagram of the inverse calculation anti-saturation method, which is used to set output limits when testing the load capacity of the controller to prevent integral saturation and large overshoot when the PI controller adjusts the reactive current.

[0089] The PI controller used in steps S62 and S64 is implemented as follows:

[0090] Step 1: Calculate the difference between the given reference value Ref and the feedback value Fdb, and use it as the input for the proportional circuit Up;

[0091] Up = Kp * (Ref - Fdb), where Kp is the proportional gain coefficient;

[0092] Step 2: Use the output Up of the proportional circuit as the input of the integral circuit;

[0093] Step 3: In the output limiting section, the difference between the input signal (OutPreSat) and the output signal (Out) is used as feedback input to the integral circuit, i.e., the saturation error SatErr. The saturation coefficient (Kc) is adjusted to control the integral adjustment desaturation capability and prevent integral saturation and large overshoot.

[0094] Step 4: Use the output Ui' of the previous cycle integrator as the positive feedback input integrator. The current integrator output Ui is obtained by the formula: Ui=Ui'+Ki*Up+Kc*SatErr, where Ki is the integral gain coefficient and SatErr is the saturation error.

[0095] Step 5: Set output limits (OutMax: maximum limit, OutMin: minimum limit) to perform anti-saturation processing. The limit values ​​are determined based on the electrical parameters of the motor at its rated operating point.

[0096] That is: Out = Up + Ui, where

[0097] like Figure 5 The figure shows the phase current waveform of the motor under no-load conditions, as follows: Figure 6 The figure shows the phase current waveform of the motor under increased current load. The reactive current I is set according to the motor's rated operating conditions. d This allows for the addition of motor phase current waveforms under no-load conditions to simulate controller load conditions, thereby enabling the testing of controller load capacity without the support platform, rapid determination of controller performance, and fulfilling the requirement for rapid iteration in controller development.

Claims

1. A method for testing the load capacity of a high-speed permanent magnet synchronous motor controller, characterized in that... Includes the following steps: Step S1. Determine the electrical parameters of the controller based on the electrical parameters of the motor at its rated operating point, including rated speed and effective value of phase current; Step S2. Calculate the rated speed based on the motor's rated frequency and number of pole pairs, and give the motor a reference speed based on the test operating point; Step S3. Set the PI controller output saturation value and the integral saturation coefficient according to the effective value of the phase current during motor test conditions; Step S4. Calculate the parameters of the inner current loop PI controller based on the motor electrical parameters and the controller control cycle, and adjust the parameters of the speed loop PI controller. Step S5. Set the target current value for testing; Step S6. Run the motor to the set speed. After the motor is running stably, increase the reactive current Id and test the controller's load-carrying capacity.

2. The load capacity test method for high-speed permanent magnet synchronous motor controller as described in claim 1, characterized in that: In step S6, the high-speed permanent magnet synchronous motor is controlled by dual closed-loop vector control of speed and current to run the motor to the set speed. The control system includes an A / D sampling module, a resolver decoding module, a PI controller, and an SVPWM module.

3. The load capacity test method for a high-speed permanent magnet synchronous motor controller as described in claim 2, characterized in that: The step S6, which employs dual closed-loop vector control of speed and current to control the high-speed permanent magnet synchronous motor, specifically includes the following steps: Step S61. Obtain the two-phase current i of the high-speed permanent magnet synchronous motor through the A / D sampling module. a and i b i a and i b The two-phase current i in the synchronous rotating coordinate system is obtained after coordinate transformation. d and i q ; Step S62. Obtain the motor rotor position θ through the resolver decoding module. e The q-axis current is obtained by subtracting the given motor speed from the feedback motor speed, along with the speed n. Step S63. and the i obtained in step 61 q After subtraction, the q-axis voltage u is obtained through a q-axis current PI controller. q ; Step S64. D-axis given current After slope treatment, it is related to the d-axis current i d The difference is used to obtain the d-axis voltage u after passing through the d-axis current PI controller. d ; Step S65.u d and u q After coordinate transformation, the voltage u in the α and β coordinate systems is obtained. α and u β ; Step S66.u α and u β After modulation by the SVPWM module, six PWM signals are generated to control the three-phase inverter and drive the high-speed permanent magnet synchronous motor.

4. The load capacity test method for high-speed permanent magnet synchronous motor controller as described in claim 3, characterized in that: In step S62, the PI controller applies an inverse calculation anti-saturation method to process the signal, including the following steps: Step S621. The difference between the reference value and the feedback value is used as the input of the proportional circuit, and the proportional term Up is output after calculation. Step S622. Use the proportional output term Up as the input to the integral stage, and apply the inverse calculation anti-saturation method. In the output limiting section, use the difference between the input signal (OutPreSat) and the output signal (Out) as the feedback input to the integral stage. Step S623. Adjust the saturation coefficient to control the integral regulation desaturation capability and prevent integral saturation and large overshoot.

5. The load capacity test method for high-speed permanent magnet synchronous motor controller as described in claim 3, characterized in that: In step S64, the PI controller applies an inverse calculation anti-saturation method to process the signal, including the following steps: Step S641. The difference between the reference value and the feedback value is used as the input of the proportional circuit, and the proportional term Up is output after calculation. Step S642. Use the proportional output term Up as the input to the integral stage, and apply the inverse calculation anti-saturation method. In the output limiting section, use the difference between the input signal (OutPreSat) and the output signal (Out) as the feedback input to the integral stage. Step S643. Adjust the saturation coefficient to control the integral regulation desaturation capability and prevent integral saturation and large overshoot.

6. The load capacity test method for a high-speed permanent magnet synchronous motor controller as described in claim 3, characterized in that: In step S61, i a and i b The two-phase current i in the synchronous rotating coordinate system is obtained after coordinate transformation. d and i q The specific transformation formula is as follows:

7. The load capacity test method for a high-speed permanent magnet synchronous motor controller as described in claim 3, characterized in that: In step S65, u d and u q After coordinate transformation, the voltage u in the α and β coordinate systems is obtained. α and u β The specific transformation formula is as follows:

8. The load capacity test method for a high-speed permanent magnet synchronous motor controller as described in claim 1, characterized in that: In step S5, setting the target test current value IS specifically involves: setting the controller's target test current based on the motor's rated operating condition electrical parameters. Since the motor's no-load active current Iq is relatively small, it can be ignored relative to the given value Id; according to the formula... Ignoring the active current Iq, the measured reactive current value is the effective value of the phase current: I s ≈I d Therefore, the target current value IS is set as the reactive current Id.

9. The load capacity test method for a high-speed permanent magnet synchronous motor controller according to claim 1, characterized in that: In step S1, the A / D sampling module samples the three-phase current and bus voltage, and performs coordinate transformation on the sampled phase currents to obtain the two-phase current i in the synchronous rotating coordinate system. a and i b .

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