Method, system and device for suppressing bus voltage pump-up during permanent magnet synchronous motor deceleration

Abstract

The application discloses a method, system and device for suppressing bus voltage pump-up of a permanent magnet synchronous motor during deceleration, and relates to the technical field of bus voltage pump-up suppression. The method comprises the following steps: obtaining a virtual angle value, an injected low-frequency alternating current amplitude, a deceleration enable flag and a motor speed signal of a current stage; determining whether the permanent magnet synchronous motor is in a deceleration stage according to the motor speed signal; when the motor is in the deceleration stage, determining an injected current value in the deceleration stage according to the virtual angle value and the injected low-frequency alternating current amplitude; determining whether the permanent magnet synchronous motor meets a current injection condition according to the deceleration enable flag; when the current injection condition is met, setting a reference input value of a current loop proportional-integral controller of a D-axis of the permanent magnet synchronous motor as the injected current value; and determining energy feedback and discharge according to the injected current value. In the process of rapid deceleration of the motor, the method suppresses the amplitude of bus voltage pump-up, and avoids the problem of circuit safety caused by excessively high amplitude of bus voltage pump-up.

Description

Technical Field

[0001] This invention relates to the field of bus voltage surge suppression technology, and in particular to a method, system and equipment for suppressing bus voltage surge during deceleration of a permanent magnet synchronous motor. Background Technology

[0002] The deceleration process of a permanent magnet synchronous motor is a process of reducing the kinetic energy of the motor rotor and the load mechanism and converting this kinetic energy into other forms of energy. The kinetic energy of the motor rotor and load is typically converted into electrical energy and heat energy dissipated through friction. The electrical energy is fed back to the motor bus via a three-phase inverter bridge circuit. If the bus is powered by a battery, it can charge the battery, achieving energy recovery. If the bus power supply does not support charging, the electrical energy will accumulate in the filter capacitor at the bus end, causing a voltage surge in the filter capacitor. The magnitude of this voltage surge is positively correlated with the rate of change of kinetic energy of the motor rotor and load during deceleration; the greater the rate of change, the greater the voltage surge. An excessively large voltage surge may cause capacitor breakdown or exceed the circuit's withstand voltage, leading to damage to the driver circuit.

[0003] In the study of the bus voltage pump-up phenomenon during deceleration of permanent magnet synchronous motors, the existing solutions and their advantages and disadvantages are as follows:

[0004] (1) Add an energy discharge channel at the bus terminal of the permanent magnet synchronous motor. The discharge channel is usually a current path composed of a braking resistor and a metal-oxide-semiconductor field-effect transistor (MOSFET). During the deceleration process of the permanent magnet synchronous motor, the microcontroller outputs a pulse width modulation wave to control the MOSFET to turn on and off at a certain frequency and duty cycle. When the MOSFET is turned on, the current flows from the positive terminal of the bus voltage through the MOSFET and the braking resistor to the negative terminal of the motor bus. The braking resistor heats up and consumes energy, which can suppress the pump-up voltage of the motor bus to a certain extent. This method requires adding a braking resistor, MOSFET and heat sink. Since the braking resistor consumes a lot of power during the deceleration process of the permanent magnet synchronous motor, a large braking resistor is often selected and a heat sink is installed, which is not conducive to reducing the size of the controller and saving costs.

[0005] (2) By slowing down the slope of the speed curve of the permanent magnet synchronous motor deceleration and extending the deceleration time, the pump voltage of the bus can be reduced to a certain extent. However, this method is not applicable to applications that require rapid deceleration and high acceleration. Summary of the Invention

[0006] The purpose of this invention is to provide a method, system, and device for suppressing bus voltage surge during deceleration of a permanent magnet synchronous motor. This method eliminates the need for an additional discharge channel composed of a braking resistor and a MOSFET, thereby suppressing the bus voltage surge during rapid motor deceleration and preventing circuit safety issues caused by excessively high bus voltage surge values.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] In a first aspect, the present invention provides a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, comprising:

[0009] Obtain the virtual angle value, low-frequency AC current amplitude, deceleration enable flag, and motor speed signal for the current stage;

[0010] Determine whether the permanent magnet synchronous motor is in the deceleration phase based on the motor speed signal;

[0011] When the permanent magnet synchronous motor is in the deceleration phase, the injected current value during the deceleration phase is determined based on the virtual angle value and the amplitude of the injected low-frequency AC current; when the permanent magnet synchronous motor is not in the deceleration phase, the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis is set to 0.

[0012] The permanent magnet synchronous motor is determined to meet the current injection condition based on the deceleration enable flag; the current injection condition is the condition that the deceleration enable flag is 1.

[0013] When the deceleration enable flag meets the current injection condition, the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis is set to the injected current value; when the deceleration enable flag does not meet the current injection condition, the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis is set to 0.

[0014] The energy feedback is determined and discharged based on the injected current value; the energy feedback is the energy feedback during deceleration of the permanent magnet synchronous motor after the copper loss of the stator winding and the iron loss of the rotor core of the permanent magnet synchronous motor are increased based on the injected current value.

[0015] Optionally, determining whether the permanent magnet synchronous motor is in the deceleration phase based on the motor speed signal specifically includes:

[0016] Determine whether the value of the motor speed signal is greater than the motor speed threshold;

[0017] Specifically, when the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration phase.

[0018] Optionally, when the permanent magnet synchronous motor is in the deceleration phase, determining the injected current value during the deceleration phase based on the virtual angle value and the amplitude of the injected low-frequency AC current specifically includes:

[0019] Set the deceleration enable flag to 1;

[0020] The virtual angle value at the current stage is accumulated according to the virtual angle step value to obtain the cumulative virtual angle value;

[0021] Determine whether the cumulative value of the virtual angle exceeds the virtual angle threshold; the virtual angle threshold is 2π.

[0022] If the cumulative virtual angle value exceeds the virtual angle threshold, the cumulative virtual angle value of the current stage is cleared to zero, and an updated virtual angle value is obtained; if the cumulative virtual angle value does not exceed the virtual angle threshold, the cumulative virtual angle value of the current stage is output, and an updated virtual angle value is obtained.

[0023] The injected current value during the deceleration phase is determined based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the formula for the injected current value.

[0024] Optionally, the formula for the injected current value is:

[0025] ThetaSin = sin(AirTheta);

[0026] InjectCurr=ThetaSin*InjectAfm;

[0027] Where ThetaSin is the virtual angle sine value, AirTheta is the updated virtual angle value, InjectCurr is the injected current value, and InjectAfm is the injected low-frequency AC current amplitude.

[0028] Secondly, the present invention provides a bus voltage surge suppression system during deceleration of a permanent magnet synchronous motor, comprising:

[0029] The bus voltage suppression variable acquisition module is used to acquire the virtual angle value, the amplitude of the injected low-frequency AC current, the deceleration enable flag, and the motor speed signal at the current stage.

[0030] The permanent magnet synchronous motor deceleration judgment module is used to determine whether the permanent magnet synchronous motor is in the deceleration stage based on the motor speed signal.

[0031] The injected current value determination module is used to determine the injected current value during the deceleration phase based on the virtual angle value and the amplitude of the injected low-frequency AC current when the permanent magnet synchronous motor is in the deceleration phase; when the permanent magnet synchronous motor is not in the deceleration phase, the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis is set to 0.

[0032] The current injection condition judgment module is used to determine whether the permanent magnet synchronous motor meets the current injection condition based on the deceleration enable flag; the current injection condition is the condition that the deceleration enable flag is 1.

[0033] The injection current value input determination module is used to set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to the injection current value when the deceleration enable flag meets the current injection condition; and to set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to 0 when the deceleration enable flag does not meet the current injection condition.

[0034] The energy feedback and discharge module is used to determine and discharge energy feedback based on the injected current value. The energy feedback is determined based on the increase in copper loss of the stator winding and iron loss of the rotor core of the permanent magnet synchronous motor after the injected current value increases, which is the energy feedback during deceleration of the permanent magnet synchronous motor.

[0035] Optionally, the permanent magnet synchronous motor deceleration judgment module specifically includes:

[0036] The motor speed signal value judgment unit is used to determine whether the value of the motor speed signal is greater than the motor speed threshold; wherein, when the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration stage.

[0037] Optionally, the injected current value determination module specifically includes:

[0038] A deceleration enable flag determination unit is used to set the deceleration enable flag to 1;

[0039] The virtual angle value accumulation unit is used to accumulate the virtual angle value of the current stage according to the virtual angle step value to obtain the virtual angle accumulation value;

[0040] A virtual angle threshold determination unit is used to determine whether the cumulative value of the virtual angle exceeds the virtual angle threshold; the virtual angle threshold is 2π.

[0041] The virtual angle value update unit is used to: when the cumulative virtual angle value exceeds the virtual angle threshold, clear the cumulative virtual angle value of the current stage to zero and obtain the updated virtual angle value; when the cumulative virtual angle value does not exceed the virtual angle threshold, output the cumulative virtual angle value of the current stage and obtain the updated virtual angle value.

[0042] The injection current value calculation unit is used to determine the injection current value during the deceleration phase based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the injection current value formula.

[0043] Thirdly, the present invention provides a device for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, comprising:

[0044] A permanent magnet synchronous motor controller is used to implement a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor.

[0045] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0046] This invention provides a method, system, and device for suppressing bus voltage surge during deceleration of a permanent magnet synchronous motor. During the deceleration and braking process of the permanent magnet synchronous motor, the method injects low-frequency AC current into the proportional-integral controller of the current loop on the D-axis of the synchronous rotating coordinate system of the permanent magnet synchronous motor. By utilizing the motor's own windings and rotor core, and increasing copper losses and eddy currents in the motor windings, a discharge path is provided for energy feedback during the deceleration and braking process of the permanent magnet synchronous motor, thus suppressing the bus voltage surge and avoiding circuit safety problems caused by excessively high bus voltage surge values. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart of a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor according to the present invention;

[0049] Figure 2 This is a control strategy diagram for a method to suppress bus voltage rise during deceleration of a permanent magnet synchronous motor according to the present invention.

[0050] Figure 3 This is a schematic diagram of the module structure of a bus voltage rise suppression system for deceleration of a permanent magnet synchronous motor according to the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The purpose of this invention is to provide a method, system, and device for suppressing bus voltage surge during deceleration of a permanent magnet synchronous motor. This method eliminates the need for an additional discharge channel composed of a braking resistor and a MOSFET, thereby suppressing the bus voltage surge during rapid motor deceleration and preventing circuit safety issues caused by excessively high bus voltage surge values.

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] Example 1

[0055] This embodiment provides a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, such as... Figure 1 As shown, the method specifically includes:

[0056] Step 101: Obtain the virtual angle value, low-frequency AC current amplitude, deceleration enable flag, and motor speed signal for the current stage.

[0057] Step 102: Determine whether the permanent magnet synchronous motor is in the deceleration stage based on the motor speed signal.

[0058] Step 103: When the permanent magnet synchronous motor is in the deceleration stage, determine the injected current value during the deceleration stage based on the virtual angle value and the amplitude of the injected low-frequency AC current; when the permanent magnet synchronous motor is not in the deceleration stage, set the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis to 0.

[0059] Step 104: Determine whether the permanent magnet synchronous motor meets the current injection condition based on the deceleration enable flag; wherein, the current injection condition is the condition that the deceleration enable flag is 1.

[0060] Step 105: When the deceleration enable flag meets the current injection condition, set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to the injected current value; when the deceleration enable flag does not meet the current injection condition, set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to 0.

[0061] Step 106: Determine and discharge energy feedback based on the injected current value; wherein, the energy feedback is the energy feedback during deceleration of the permanent magnet synchronous motor determined by increasing the copper loss of the stator winding and the iron loss of the rotor core of the permanent magnet synchronous motor based on the injected current value.

[0062] In a preferred embodiment, before performing step 101, the method further includes: creating initial variables such as injection current, virtual angle, sine value of virtual angle, virtual angle step size, injection low-frequency AC current amplitude, and deceleration enable flag; after completing the creation of each variable, it is also necessary to set the initial values ​​of injection current, virtual angle, sine value of virtual angle, virtual angle step size, injection low-frequency AC current amplitude, and deceleration enable flag.

[0063] Further, step 102 specifically includes: first determining whether the value of the motor speed signal is greater than the motor speed threshold, wherein the motor speed threshold is a motor speed command setting value manually input by the outside according to actual needs. When the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration stage, and at the same time, the reference input value of the speed loop proportional-integral controller of the permanent magnet synchronous motor will decrease at a fixed slope; when the reference input value of the speed loop proportional-integral controller of the permanent magnet synchronous motor is equal to the motor speed threshold, the reference input value of the speed loop proportional-integral controller of the permanent magnet synchronous motor no longer decreases, and at this time it is determined that the deceleration stage of the permanent magnet synchronous motor has ended.

[0064] Furthermore, in order to facilitate the determination of current injection conditions and the calculation of injection current value in step 104, in step 103: firstly, the deceleration enable flag needs to be set to 1.

[0065] When the permanent magnet synchronous motor is determined to be in the deceleration phase, the virtual angle value of the current phase is accumulated according to the virtual angle step value to obtain the cumulative virtual angle value. It is then determined whether this cumulative virtual angle value exceeds the virtual angle threshold, where the virtual angle threshold is 2π. If the cumulative virtual angle value exceeds the virtual angle threshold, the cumulative virtual angle value of the current phase is cleared to zero, resulting in an updated virtual angle value. If the cumulative virtual angle value does not exceed the virtual angle threshold, the cumulative virtual angle value of the current phase is output, resulting in an updated virtual angle value.

[0066] Finally, based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the injection current formula, the injection current value during the deceleration phase is determined. Specifically, the injection current formula is as follows:

[0067] ThetaSin = sin(AirTheta);

[0068] InjectCurr=ThetaSin*InjectAfm;

[0069] In the formula, ThetaSin is the virtual angle sine value, AirTheta is the updated virtual angle value, InjectCurr is the injected current value, and InjectAfm is the injected low-frequency AC current amplitude.

[0070] In fact, the main function of step 103 is to calculate the amount of low-frequency AC current that needs to be injected into the D-axis of the permanent magnet synchronous motor at each control cycle during the deceleration period of the permanent magnet synchronous motor.

[0071] To more clearly analyze the inhibition process of the above method, the following will combine... Figure 2 This paper presents a control strategy for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor. The execution process of the entire algorithm is described in detail below:

[0072] Under default conditions, the control strategy determines that the system is in a non-deceleration process. At this time, the output value of the first switching module is the output value of the speed loop module, and the output value of the second switching module is I. d * = 0, I d *Reference value for the D-axis current loop of the permanent magnet synchronous motor.

[0073] When the control strategy determines that the system is initiating a deceleration process, it sets the deceleration enable flag SlowFlag to 1. At this time, the output value of the first switching module is I. q * = -0.04, starting to control the permanent magnet synchronous motor to output reverse torque, reducing the motor speed. At this time, the output value of the second switching module is I. d *=I Amp sin(2πf inject t), where I q * is the reference value for the Q-axis current loop of the permanent magnet synchronous motor, I Amp f represents the magnitude of the injected current. inject The frequency value of the injected current is -9 to 9Hz, indicating the start of injecting AC current into the D-axis of the permanent magnet synchronous motor to discharge the energy feedback caused by the deceleration of the permanent magnet synchronous motor and the load, and to suppress the rise of the bus voltage.

[0074] The output value of the first switching module is compared with the calculated value of the Q-axis current of the permanent magnet synchronous motor, I. q fed The difference is used to obtain the Q-axis current error value; this value is then input into the permanent magnet synchronous motor (PMSM) Q-axis current loop module, which calculates the PMSM Q-axis voltage output value ν. q *; The synchronous / stationary coordinate transformation module utilizes ν q *Calculate the voltage output value ν of the α axis of the permanent magnet synchronous motor. α * .

[0075] The output value of the second switching module is compared with the calculated value of the D-axis current of the permanent magnet synchronous motor, I. d fed The difference is used to obtain the D-axis current error value; this value is then input into the permanent magnet synchronous motor (PMSM) D-axis current loop module, which calculates the D-axis voltage output value ν of the PMSM. d * The synchronous / stationary coordinate transformation module utilizes ν d * The voltage output value ν of the β-axis of the permanent magnet synchronous motor was calculated. β * .

[0076] Finally, ν α * and ν β The data are input into the space vector pulse width modulation module to calculate the three-phase duty cycle data, and then output as six complementary PWM control signals through modulation. The three-phase motor current I is measured externally using a current sensor. a,b,c fed The static / synchronous coordinate transformation module outputs the calculated current values ​​I for the D-axis and Q-axis of the permanent magnet synchronous motor. d,q fed This enables closed-loop control of the motor current.

[0077] also, Figure 2 The ω* mentioned is the speed reference input value of the speed loop, ω is the measured speed value of the permanent magnet synchronous motor, and θ is the measured rotor angle value of the permanent magnet synchronous motor.

[0078] Example 2

[0079] This embodiment provides a bus voltage rise suppression system during deceleration of a permanent magnet synchronous motor, such as... Figure 3 As shown, the system specifically includes:

[0080] The bus voltage suppression variable acquisition module 201 is used to acquire the virtual angle value, the amplitude of the injected low-frequency AC current, the deceleration enable flag, and the motor speed signal at the current stage.

[0081] The permanent magnet synchronous motor deceleration judgment module 202 is used to determine whether the permanent magnet synchronous motor is in the deceleration stage based on the motor speed signal.

[0082] The injection current value determination module 203 is used to determine the injection current value during the deceleration phase based on the virtual angle value and the amplitude of the injected low-frequency AC current when the permanent magnet synchronous motor is in the deceleration phase; when the permanent magnet synchronous motor is not in the deceleration phase, the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis is set to 0.

[0083] The current injection condition judgment module 204 is used to determine whether the permanent magnet synchronous motor meets the current injection condition based on the deceleration enable flag; the current injection condition is the condition that the deceleration enable flag is 1.

[0084] The injection current value input determination module 205 is used to set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to the injection current value when the deceleration enable flag meets the current injection condition; and to set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to 0 when the deceleration enable flag does not meet the current injection condition.

[0085] The energy feedback and discharge module 206 is used to determine and discharge energy feedback based on the injected current value. The energy feedback is determined by the increase in copper loss of the stator winding and iron loss of the rotor core of the permanent magnet synchronous motor due to the injected current value, which is the energy feedback during deceleration of the permanent magnet synchronous motor.

[0086] The permanent magnet synchronous motor deceleration judgment module 202 specifically includes:

[0087] The motor speed signal value judgment unit 2021 is used to determine whether the value of the motor speed signal is greater than the motor speed threshold; wherein, when the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration stage.

[0088] Furthermore, the injected current value determination module 203 specifically includes:

[0089] The deceleration enable flag determination unit 2031 is used to set the deceleration enable flag to 1.

[0090] The virtual angle value accumulation unit 2032 is used to accumulate the virtual angle value of the current stage according to the virtual angle step value to obtain the virtual angle accumulation value.

[0091] The virtual angle threshold judgment unit 2033 is used to determine whether the cumulative value of the virtual angle exceeds the virtual angle threshold; wherein, the virtual angle threshold is 2π.

[0092] The virtual angle value update unit 2034 is used to clear the current stage's virtual angle cumulative value to zero and obtain the updated virtual angle value when the virtual angle cumulative value exceeds the virtual angle threshold; and to output the current stage's virtual angle cumulative value and obtain the updated virtual angle value when the virtual angle cumulative value does not exceed the virtual angle threshold.

[0093] The injection current calculation unit 2035 is used to determine the injection current value during the deceleration phase based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the injection current value formula.

[0094] Furthermore, the present invention also provides a device for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, specifically comprising:

[0095] A permanent magnet synchronous motor controller is used to execute a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor as described in Embodiment 1.

[0096] In summary, compared with existing technical solutions, the method for suppressing bus voltage rise during deceleration of permanent magnet synchronous motors has the following advantages:

[0097] 1) This method allows for the suppression of bus voltage rise during deceleration of a permanent magnet synchronous motor (PMSM) without requiring additional MOSFETs and braking resistors, simplifying circuit design and reducing hardware cost and size. By utilizing the stator windings and rotor core of the PMSM, the power factor of the motor is reduced, increasing copper losses in the stator windings and iron losses in the rotor core, thus consuming energy feedback during deceleration and suppressing bus voltage rise.

[0098] 2) This method is a software control method to suppress bus voltage rise. It is essentially a software operation process with a simple control flow. It does not involve complex control algorithms and has low performance requirements for microcontrollers, thus having universality.

[0099] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0100] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, characterized in that, include: Obtain the virtual angle value, low-frequency AC current amplitude, deceleration enable flag, and motor speed signal for the current stage; Determine whether the permanent magnet synchronous motor is in the deceleration phase based on the motor speed signal; When the permanent magnet synchronous motor is in the deceleration phase, the injected current value during the deceleration phase is determined based on the virtual angle value and the amplitude of the injected low-frequency AC current. When the permanent magnet synchronous motor is not in the deceleration stage, set the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis to 0; The permanent magnet synchronous motor is determined to meet the current injection condition based on the deceleration enable flag; the current injection condition is the condition that the deceleration enable flag is 1. When the deceleration enable flag meets the current injection condition, the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis is set to the injected current value. When the deceleration enable flag does not meet the current injection condition, the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis is set to 0. The energy feedback is determined and discharged based on the injected current value; the energy feedback is the energy feedback during deceleration of the permanent magnet synchronous motor after the copper loss of the stator winding and the iron loss of the rotor core of the permanent magnet synchronous motor are increased based on the injected current value.

2. The method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor according to claim 1, characterized in that, Determining whether the permanent magnet synchronous motor is in the deceleration phase based on the motor speed signal specifically includes: Determine whether the value of the motor speed signal is greater than the motor speed threshold; Specifically, when the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration phase.

3. The method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor according to claim 1, characterized in that, When the permanent magnet synchronous motor is in the deceleration phase, the injected current value during the deceleration phase is determined based on the virtual angle value and the amplitude of the injected low-frequency AC current, specifically including: Set the deceleration enable flag to 1; The virtual angle value at the current stage is accumulated according to the virtual angle step value to obtain the cumulative virtual angle value; Determine whether the cumulative value of the virtual angle exceeds the virtual angle threshold; the virtual angle threshold is 2π. If the cumulative virtual angle value exceeds the virtual angle threshold, the cumulative virtual angle value of the current stage is cleared to zero, and an updated virtual angle value is obtained; if the cumulative virtual angle value does not exceed the virtual angle threshold, the cumulative virtual angle value of the current stage is output, and an updated virtual angle value is obtained. The injected current value during the deceleration phase is determined based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the formula for the injected current value.

4. The method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor according to claim 3, characterized in that, The formula for the injected current value is: ThetaSin = sin(AirTheta); InjectCurr=ThetaSin*InjectAfm; Where ThetaSin is the virtual angle sine value, AirTheta is the updated virtual angle value, InjectCurr is the injected current value, and InjectAfm is the injected low-frequency AC current amplitude.

5. A bus voltage rise suppression system during deceleration of a permanent magnet synchronous motor, characterized in that, include: The bus voltage suppression variable acquisition module is used to acquire the virtual angle value, the amplitude of the injected low-frequency AC current, the deceleration enable flag, and the motor speed signal at the current stage. The permanent magnet synchronous motor deceleration judgment module is used to determine whether the permanent magnet synchronous motor is in the deceleration stage based on the motor speed signal. The injected current value determination module is used to determine the injected current value during the deceleration phase based on the virtual angle value and the amplitude of the injected low-frequency AC current when the permanent magnet synchronous motor is in the deceleration phase. When the permanent magnet synchronous motor is not in the deceleration stage, set the reference input value of the proportional-integral controller of the current loop of the permanent magnet synchronous motor D-axis to 0; The current injection condition judgment module is used to determine whether the permanent magnet synchronous motor meets the current injection condition based on the deceleration enable flag; the current injection condition is the condition that the deceleration enable flag is 1. The injection current value input determination module is used to set the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis to the injection current value when the deceleration enable flag meets the current injection condition. When the deceleration enable flag does not meet the current injection condition, the reference input value of the current loop proportional-integral controller of the permanent magnet synchronous motor D-axis is set to 0. The energy feedback and discharge module is used to determine and discharge energy feedback based on the injected current value. The energy feedback is determined based on the increase in copper loss of the stator winding and iron loss of the rotor core of the permanent magnet synchronous motor after the injected current value increases, which is the energy feedback during deceleration of the permanent magnet synchronous motor.

6. The bus voltage rise suppression system for permanent magnet synchronous motor deceleration according to claim 5, characterized in that, The permanent magnet synchronous motor deceleration judgment module specifically includes: The motor speed signal value judgment unit is used to determine whether the value of the motor speed signal is greater than the motor speed threshold; wherein, when the value of the motor speed signal is greater than the motor speed threshold, it is determined that the permanent magnet synchronous motor is in the deceleration stage.

7. The bus voltage rise suppression system for permanent magnet synchronous motor deceleration according to claim 5, characterized in that, The injected current value determination module specifically includes: A deceleration enable flag determination unit is used to set the deceleration enable flag to 1; The virtual angle value accumulation unit is used to accumulate the virtual angle value of the current stage according to the virtual angle step value to obtain the virtual angle accumulation value; A virtual angle threshold determination unit is used to determine whether the cumulative value of the virtual angle exceeds the virtual angle threshold; the virtual angle threshold is 2π. The virtual angle value update unit is used to: when the cumulative virtual angle value exceeds the virtual angle threshold, clear the cumulative virtual angle value of the current stage to zero and obtain the updated virtual angle value; when the cumulative virtual angle value does not exceed the virtual angle threshold, output the cumulative virtual angle value of the current stage and obtain the updated virtual angle value. The injection current value calculation unit is used to determine the injection current value during the deceleration phase based on the updated virtual angle value, the amplitude of the injected low-frequency AC current, and the injection current value formula.

8. A device for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor, characterized in that, include: A permanent magnet synchronous motor controller for executing a method for suppressing bus voltage rise during deceleration of a permanent magnet synchronous motor as described in any one of claims 1-4.

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