A method and apparatus for fast discharging

Abstract

The application provides a method and device for fast discharging. In the method, firstly, three-phase current generated by a motor is converted into first current in the direct-axis direction of the motor and second current in the cross-axis direction of the motor through coordinate transformation. A preset model corresponding to the first voltage in the direct-axis direction of the motor is obtained. According to the first current, the second current and the preset model, the second voltage in the cross-axis direction of the motor is obtained. The fast discharging is performed by using the second voltage. In this way, the voltage in the cross-axis direction is obtained by using the preset model related to the voltage in the direct-axis direction, open-loop processing is performed, and the problem that the PI adjusting parameter set in advance causes the current loop to be in an out-of-control state when the bus end voltage rapidly decreases is avoided. The motor output torque fluctuation and the three-phase current fluctuation generated by the motor are reduced in the process of ensuring the fast discharging.

Description

Technical Field

[0001] This application relates to the field of permanent magnet synchronous motors, and in particular to a method and apparatus for rapid discharge. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in various applications due to their high efficiency and high power density. In high-performance applications, PMSMs are generally required to have rapid discharge capability. Rapid discharge refers to the ability to quickly discharge the charge in the PMSM controller capacitor within a specified time after disconnecting the high-voltage power connection, causing the controller bus voltage to drop rapidly below a safe value. For example, GB / T18488 specifies a drop to below 60V within three seconds.

[0003] Current technology employs a combination of PI control and current closed-loop control for rapid discharge. Specifically, the permanent magnet synchronous motor (PMSM) first generates three-phase current, then performs coordinate transformation to obtain currents along the direct (D-axis) and quadrature (Q-axis) directions. PI control is then applied to these currents to obtain voltages along the D-axis and Q-axis for rapid discharge. However, PI control requires preset parameters, and these parameters only function correctly under specific voltage conditions. Therefore, when rapidly discharging the capacitor in the PMSM controller, PI control fails to operate correctly. This causes the current loop to become uncontrolled. This uncontrolled current loop leads to fluctuations in motor output torque and significant fluctuations in the generated three-phase current.

[0004] Therefore, ensuring minimal fluctuations in motor output torque and three-phase current during rapid discharge is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, this application provides a method and apparatus for rapid discharge, which aims to reduce the fluctuation of motor output torque and the fluctuation of three-phase current during the rapid discharge process.

[0006] In a first aspect, embodiments of this application provide a method for rapid discharge, the method comprising:

[0007] A first current and a second current are obtained; the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor; the first current is the current in the direct axis direction of the motor; the second current is the current in the quadrature axis direction of the motor.

[0008] Obtain a preset model; the preset model is used to process the first current and the second current; the preset model corresponds to a first voltage; the first voltage is the voltage in the direct axis direction of the motor;

[0009] Based on the first current, the second current, and the preset model, a second voltage is determined; the second voltage is the voltage in the cross-axis direction of the motor.

[0010] Rapid discharge is performed based on the second voltage.

[0011] Optionally, the first voltage is obtained in the following way:

[0012] Obtain a preset capacitor voltage-direct axis voltage curve; the preset capacitor voltage-direct axis voltage curve is a smooth curve; the horizontal axis of the preset capacitor voltage-direct axis voltage curve is used to represent the voltage in the direct axis direction of the motor, and the vertical axis is used to represent the capacitor voltage;

[0013] Obtain a preset voltage; the preset voltage is the capacitor voltage in the motor controller.

[0014] The first voltage is determined based on the preset voltage and the preset capacitor voltage-direct axis voltage curve.

[0015] Optionally, the preset model is obtained in the following way:

[0016] In response to the motor's output torque being 0, the mapping relationship between the second voltage and the first voltage, the first current, and the second current is obtained;

[0017] A preset model is obtained based on the mapping relationship between the second voltage and the first voltage, the first current and the second current.

[0018] Optionally, after obtaining the second voltage, the method further includes:

[0019] Perform an inverse Park transform on the first voltage and the second voltage;

[0020] The processed first voltage and second voltage are input to the space vector pulse width modulation unit to generate a pulse width modulation signal;

[0021] The three-phase inverter is controlled to drive the motor according to the pulse width modulation signal, and the motor is discharged quickly.

[0022] Optionally, the coordinate transformation includes: Park transformation, and / or Clarke transformation.

[0023] Secondly, embodiments of this application provide a device for rapid discharge, the device comprising:

[0024] The first acquisition unit is used to acquire a first current and a second current; the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor; the first current is the current in the direct axis direction of the motor; the second current is the current in the quadrature axis direction of the motor.

[0025] The second acquisition unit is used to acquire a preset model; the preset model is used to process the first current and the second current; the preset model corresponds to a first voltage; the first voltage is the voltage in the direct axis direction of the motor;

[0026] The determining unit is used to determine the second voltage based on the first current, the second current, and the preset model; the second voltage is the voltage in the quadrature axis direction of the motor;

[0027] A discharge unit is used to perform rapid discharge based on the second voltage.

[0028] Optionally, the second acquisition unit is further configured to acquire a preset capacitor voltage-direct axis voltage curve; the preset capacitor voltage-direct axis voltage curve is a smooth curve; the horizontal axis of the preset capacitor voltage-direct axis voltage curve is used to represent the voltage in the direct axis direction of the motor, and the vertical axis is used to represent the capacitor voltage; it is also configured to acquire a preset voltage; the preset voltage is the capacitor voltage in the motor controller.

[0029] Optionally, the device further includes:

[0030] The inverse Parker transformation module is used to perform inverse Parker transformation on the first voltage and the second voltage.

[0031] The generation module is used to input the processed first voltage and second voltage to the space vector pulse width modulation unit and generate a pulse width modulation signal;

[0032] The discharge module is used to control the three-phase inverter to drive the motor according to the pulse width modulation signal, so as to perform rapid discharge of the motor.

[0033] Thirdly, a computer device includes a memory and a processor; the memory stores computer-readable instructions that, when executed by the processor, cause the processor to perform the rapid discharge method steps described in the first aspect.

[0034] Fourthly, embodiments of this application provide a computer-readable storage medium storing a program or code that, when executed by a processor, implements the steps of the fast discharge method described in the first aspect above.

[0035] This application provides a method and apparatus for rapid discharge. When executing the method, the three-phase current generated by the motor is first converted into a first current in the direct axis direction and a second current in the quadrature axis direction through coordinate transformation. A preset model corresponding to the first voltage in the direct axis direction of the motor is then obtained. Based on the first current, the second current, and the preset model, the second voltage in the quadrature axis direction of the motor can be obtained. Rapid discharge is then performed using this second voltage. Thus, by obtaining the voltage in the quadrature axis direction through the preset model related to the voltage in the direct axis direction and performing open-loop processing, the problem of the pre-set PI regulation causing the current loop to become uncontrolled due to a rapid drop in the bus terminal voltage is avoided. This ensures rapid discharge while reducing fluctuations in motor output torque and three-phase current. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of a technical solution combining PI regulation and current closed-loop control;

[0038] Figure 2 A flowchart of a rapid discharge method provided in an embodiment of this application;

[0039] Figure 3 A flowchart illustrating a method for obtaining voltage in the D-axis direction of a motor, as provided in this application embodiment;

[0040] Figure 4 This is a schematic diagram of the capacitor voltage-D-axis voltage curve;

[0041] Figure 5 A flowchart illustrating another rapid discharge method provided in this application embodiment;

[0042] Figure 6 This is a schematic diagram of a device structure for rapid discharge provided in an embodiment of this application. Detailed Implementation

[0043] The terms “first,” “second,” “third,” and “fourth,” etc., used in this application specification, claims, and drawings are used to distinguish different objects, not to limit a specific order.

[0044] In the embodiments of this application, the terms "as an example" or "for example" are used to indicate that they are examples, illustrations, or explanations. Any embodiment or design that is described as "as an example" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of terms such as "as an example" or "for example" is intended to present the relevant concepts in a specific manner.

[0045] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0046] As mentioned earlier, existing technologies often employ a combination of PI regulation and current closed-loop control for rapid discharge. (See also...) Figure 1 This diagram illustrates a technical solution combining PI control and current closed-loop control. Specifically, the three-phase currents (UVW) generated by the motor are transformed into Q-axis and D-axis currents through coordinate transformation. These currents are processed by different comparators. The processed Q-axis and D-axis currents are then divided into two paths and controlled by different PI controllers to obtain Q-axis and D-axis voltages, respectively. The voltages in both directions are then transformed using an inverse Park transformation to obtain α-axis and β-axis voltages for rapid current closed-loop discharge. However, PI control requires preset PI control parameters, which are only applicable to certain voltage conditions. Therefore, when rapidly discharging the capacitor in the permanent magnet synchronous motor controller, PI control malfunctions. This causes the current loop to become uncontrolled. This uncontrolled current loop leads to fluctuations in motor output torque and significant fluctuations in three-phase current.

[0047] This application provides a method for rapid discharge. First, the three-phase current generated by the motor is transformed using coordinate transformation to determine the first current in the direct axis direction and the second current in the quadrature axis direction. A preset model corresponding to the first voltage in the direct axis direction of the motor is then obtained. Based on the first current, the second current, and the preset model, the second voltage in the quadrature axis direction of the motor can be obtained. Rapid discharge is then performed using this second voltage. Thus, by obtaining the voltage in the quadrature axis direction through the preset model related to the voltage in the direct axis direction and performing open-loop processing, the problem of the current loop becoming uncontrolled due to a rapid drop in the bus voltage caused by the pre-set PI control parameters is avoided. This ensures rapid discharge while reducing fluctuations in motor output torque and three-phase current.

[0048] The rapid discharge method provided in this application is mainly applied to the control of permanent magnet synchronous motors. Specifically, after disconnecting the high-voltage power connection, the charge in the capacitor of the permanent magnet synchronous motor controller is rapidly discharged within a specified time, causing the voltage at the controller bus terminals to drop quickly below a safe value.

[0049] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0050] Figure 2 A flowchart illustrating a rapid discharge method provided in this application embodiment. The method includes at least the following steps:

[0051] S201: Obtain the first current and the second current.

[0052] The technical solution provided in this application embodiment can be executed by a motor control system. The motor control system can obtain the first current and the second current in various ways. The first current is the current in the D-axis direction of the motor, and the second current is the current in the Q-axis direction of the motor. The D-axis and Q-axis are coordinate axes, which are a coordinate system established on the rotor of the permanent magnet synchronous motor to obtain control characteristics similar to those of a DC motor. The direction of the rotor magnetic field is the D-axis, and the direction perpendicular to the magnetic field is the Q-axis.

[0053] In this embodiment, both the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor. In this embodiment, the coordinate transformation can be a Park transformation, a Clark transformation, or a combination of both.

[0054] S202: Obtain the preset model.

[0055] In this embodiment, the motor control system needs to obtain a preset model. The preset model is used to process the above step S201 to obtain the first current and the second current, in order to obtain the voltage in the Q-axis direction. In this embodiment, the preset model corresponds to the first voltage, which is the voltage in the D-axis direction of the motor.

[0056] In this embodiment of the application, the preset model can be a mapping relationship between the voltage in the Q-axis direction and the first current, the second current and the first voltage, and the phase resistance of the motor.

[0057] As an example: assume the voltage along the Q-axis is U. q The first current is I d The second current is I q The first voltage is U d The phase resistance of the motor is R. Therefore, the preset model can be:

[0058] U q =k1Ud +k2RI d +k3RI q

[0059] Among them, k1, k2, and k3 are arbitrary random numbers, which can be set by those skilled in the art as needed.

[0060] In this embodiment of the application, in order to better achieve a smaller torque during the rapid discharge process, a mapping relationship can be constructed between the voltage in the Q-axis direction and the first current, the second current and the first voltage, and the phase resistance of the motor, under the premise that the output torque is 0.

[0061] In this embodiment, the voltage along the Q-axis is U. q The first current is I d The second current is I q The first voltage is U d If the phase resistance of the motor is R, then under the premise that the output torque is 0, the preset model is obtained as follows:

[0062]

[0063] In this embodiment, the first voltage can be obtained by referring to the capacitor voltage-D-axis voltage curve. Specifically, the horizontal axis of the voltage-D-axis voltage curve represents the commanded value of the D-axis voltage, and the vertical axis represents the capacitor voltage value. For the motor, obtaining the capacitor voltage allows the determination of the voltage value in the D-axis direction. In this embodiment, the voltage value is negative to enable subsequent SVPWM control to generate a PWM signal.

[0064] In this embodiment, the capacitor voltage-D-axis voltage curve can be a smooth curve. This further reduces fluctuations in the three-phase output current and output torque of the motor. In this embodiment, the capacitor voltage-D-axis voltage curve can be obtained by drawing a straight line or a parabola.

[0065] As an example: The commanded values ​​for the D-axis voltage are (-10, -20, -30), corresponding to capacitor voltages of (60, 120, 180). That is, -10 corresponds to 60, -20 to 120, and -30 to 180. In a Cartesian coordinate system, either a straight line or a curve can be constructed to represent the capacitor voltage - D-axis voltage curve. For example, the X-axis direction represents the commanded D-axis voltage value, and the Y-axis direction represents the capacitor voltage. Based on the above correspondence, a straight line representing the capacitor voltage - D-axis voltage can be drawn in a Cartesian coordinate system. This straight line is the capacitor voltage - D-axis voltage curve that meets the requirements.

[0066] S203: Determine the second voltage based on the first current, the second current, and the preset model.

[0067] After obtaining the first current, the second current, and the preset model, the first current and the second current are input into the preset model to obtain the second voltage. The second voltage is the voltage in the quadrature axis direction of the motor. By obtaining the voltage in the quadrature axis direction through a preset model related to the voltage in the direct axis direction, the voltage acquisition in the Q-axis direction is avoided from depending on the PI parameters. This avoids the problem of the current loop being out of control due to a rapid drop in the bus terminal voltage caused by the preset PI adjustment parameters.

[0068] S204: Perform rapid discharge based on the second voltage.

[0069] In this embodiment, the executing entity can compare the acquired second voltage with the first voltage and adjust the second voltage. Then, an inverse Park transformation is performed on the adjusted second and first voltages, followed by rapid discharge processing. In this embodiment, open-loop control is achieved using given voltage commands in the D-axis and Q-axis directions, eliminating dependence on current loop PI parameters. This avoids the problem of the pre-set PI adjustment parameters causing the current loop to become uncontrolled due to a rapid drop in bus voltage. Consequently, during subsequent rapid discharge, the fluctuations in motor output torque and the fluctuations in three-phase current are reduced.

[0070] In this embodiment, the processed first voltage and second voltage can also be input to the space vector pulse width modulation unit to generate a pulse width modulation signal; the three-phase inverter can be controlled to drive the motor according to the pulse width modulation signal to perform rapid motor discharge.

[0071] This application provides a method for rapid discharge. Through coordinate transformation, the three-phase current generated by the motor is converted into a first current in the direct axis direction and a second current in the quadrature axis direction. A preset model corresponding to the first voltage in the direct axis direction of the motor is obtained. Based on the first current, the second current, and the preset model, the second voltage in the quadrature axis direction of the motor can be obtained. Rapid discharge is then performed using this second voltage. Thus, by obtaining the voltage in the quadrature axis direction through the preset model related to the voltage in the direct axis direction and performing open-loop processing, the problem of the current loop becoming uncontrolled due to a rapid drop in the bus voltage caused by the pre-set PI adjustment parameters is avoided. This ensures rapid discharge while reducing fluctuations in motor output torque and three-phase current.

[0072] about Figure 2 There are multiple ways to obtain the first voltage. Figure 3 A flowchart illustrating a method for obtaining voltage along the D-axis of a motor, provided in an embodiment of this application. The method includes at least the following steps:

[0073] S301: Construct the capacitor voltage-D-axis voltage curve.

[0074] The capacitor voltage curve described above is along the X-axis. The D-axis voltage is along the Y-axis. The X and Y axes are the horizontal and vertical coordinates in a Cartesian coordinate system. In this embodiment, the capacitor voltage-D-axis voltage curve can be plotted using either a straight line or a curve. In this embodiment, taking a straight line as an example, assume the capacitor voltage value can be selected from three values: a maximum of 540V, a minimum of 60V, and a median of 270V. The D-axis voltage command value corresponding to the maximum value of 540V is determined to be -200V, the D-axis voltage command value corresponding to the minimum value of 60V is -50V, and the D-axis voltage command value corresponding to the median value of 270V is -100V. This constructs a straight line for the capacitor voltage-D-axis voltage curve. Specifically... Figure 4 The above is a schematic diagram of the capacitor voltage-D-axis voltage curve.

[0075] It should be noted that, in this embodiment, the D-axis voltage command value is set according to the discharge requirements. These requirements include the discharge time and the post-discharge bus voltage value. The D-axis voltage command value corresponding to the maximum capacitor voltage is generally half of the maximum bus voltage. At this point, the discharge effect is optimal.

[0076] S302: Obtain the capacitor voltage value of the motor.

[0077] In this embodiment, a sensor can be used to collect the capacitor voltage value of the motor in real time. For example, the sensor collects the capacitor voltage value of the motor once every 1ms.

[0078] S303: Based on the capacitor voltage value and the capacitor voltage-D-axis voltage curve, obtain the voltage in the D-axis direction by querying.

[0079] The XY curves plotted using the above method are smooth with no obvious bulges, and Y increases negatively with increasing X. This fully considers the rapid discharge requirements of the motor. This method is then applied. Figure 2 The aforementioned rapid discharge method can further reduce the fluctuation of the three-phase current output of the motor, thereby reducing the fluctuation of the output torque.

[0080] Figure 5 A flowchart illustrating another rapid discharge method provided in this application embodiment. The method includes at least the following steps:

[0081] S501: Obtain the UVW three-phase current generated by the motor.

[0082] S502: Obtain the i-axis direction by performing coordinate transformation on the UVW three-phase currents. q and the current i in the D-axis direction d .

[0083] S503: Obtain the voltage Ud in the D-axis direction.

[0084] The method of obtaining is Figure 3 The method for obtaining the voltage in the D-axis direction will not be discussed here.

[0085] S504: i q i d And input the preset formula into Ud to obtain Uq' in the Q-axis direction.

[0086] S505: Determine whether Uq' is greater than Ud. If yes, proceed to step S406; otherwise, proceed to step S407.

[0087] S506: Uq' and Ud are processed by the inverse Park transformation to obtain Uα and U... β .

[0088] S507: Replace the voltage Uq in the Q-axis direction with Ud, and obtain Uα and Ud by performing an inverse Park transformation on Uq and Ud. β

[0089] S508: Place Uα and U... β The input SVPWM generates a PWM signal, which is applied to the motor controller to quickly discharge the capacitor current in the motor controller.

[0090] The fast discharge method provided in this application eliminates the dependence on the current loop PI parameters by using open-loop control of the given voltages in the D-axis and Q-axis directions, thereby reducing calibration workload while achieving fast discharge. Furthermore, by querying the D-axis voltage from the smooth capacitor voltage-D-axis voltage curve, the fluctuation of the three-phase current can be further reduced.

[0091] Furthermore, embodiments of this application also provide a device for rapid discharge. Figure 6 A schematic diagram 600 of a fast discharge device is provided for embodiments of this application. The device 600 includes at least the following parts:

[0092] The first acquisition unit 601 is used to acquire a first current and a second current; the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor; the first current is the current in the direct axis direction of the motor; the second current is the current in the quadrature axis direction of the motor.

[0093] The second acquisition unit 602 is used to acquire a preset model; the preset model is used to process the first current and the second current; the preset model corresponds to a first voltage; the first voltage is the voltage in the direct axis direction of the motor;

[0094] The determining unit 603 is used to determine a second voltage based on the first current, the second current, and the preset model; the second voltage is the voltage in the cross-axis direction of the motor;

[0095] The discharge unit 604 is used to perform rapid discharge according to the second voltage.

[0096] Optionally, the second acquisition unit 602 is further configured to acquire a preset capacitor voltage-direct axis voltage curve; the preset capacitor voltage-direct axis voltage curve is a smooth curve; the horizontal axis of the preset capacitor voltage-direct axis voltage curve is used to represent the voltage in the direct axis direction of the motor, and the vertical axis is used to represent the capacitor voltage; it is also configured to acquire a preset voltage; the preset voltage is the capacitor voltage in the motor controller.

[0097] Optionally, the device 600 further includes:

[0098] The inverse Parker transformation module is used to perform inverse Parker transformation on the first voltage and the second voltage.

[0099] The generation module is used to input the processed first voltage and second voltage to the space vector pulse width modulation unit and generate a pulse width modulation signal;

[0100] The discharge module is used to control the three-phase inverter to drive the motor according to the pulse width modulation signal, so as to perform rapid discharge of the motor.

[0101] In one embodiment, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described fast discharge method.

[0102] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the fast discharge method of this application.

[0103] In practical applications, the computer-readable storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0104] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0105] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0106] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0107] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0108] The above description is merely an exemplary implementation of this application and is not intended to limit the scope of protection of this application.

Claims

1. A method for rapid discharge, characterized in that, The method includes: A first current and a second current are obtained; the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor; the first current is the current in the direct axis direction of the motor; the second current is the current in the quadrature axis direction of the motor. Obtain a preset model; the preset model is used to process the first current and the second current; the preset model corresponds to a first voltage; the first voltage is the voltage in the direct axis direction of the motor; Based on the first current, the second current, and the preset model, a second voltage is determined; the second voltage is the voltage in the cross-axis direction of the motor. Perform rapid discharge based on the second voltage; The first voltage is obtained in the following way: Obtain a preset capacitor voltage-direct axis voltage curve; the preset capacitor voltage-direct axis voltage curve is a smooth curve; the horizontal axis of the preset capacitor voltage-direct axis voltage curve is used to represent the voltage in the direct axis direction of the motor, and the vertical axis is used to represent the capacitor voltage; Obtain a preset voltage; the preset voltage is the capacitor voltage in the motor controller; The first voltage is determined based on the preset voltage and the preset capacitor voltage-direct axis voltage curve; The preset model is obtained through the following methods: In response to the motor's output torque being 0, the mapping relationship between the second voltage and the first voltage, the first current, and the second current is obtained; A preset model is obtained based on the mapping relationship between the second voltage and the first voltage, the first current, and the second current.

2. The method according to claim 1, characterized in that, After obtaining the second voltage, the method further includes: Perform an inverse Park transform on the first voltage and the second voltage; The processed first voltage and second voltage are input to the space vector pulse width modulation unit to generate a pulse width modulation signal; The three-phase inverter is controlled to drive the motor according to the pulse width modulation signal, and the motor is discharged quickly.

3. The method according to claim 1, characterized in that, The coordinate transformations include: Park transformation, and / or Clarke transformation.

4. A device for rapid discharge, characterized in that, The device includes: The first acquisition unit is used to acquire a first current and a second current; the first current and the second current are determined by coordinate transformation based on the three-phase current generated by the motor; the first current is the current in the direct axis direction of the motor; the second current is the current in the quadrature axis direction of the motor. The second acquisition unit is used to acquire a preset model; the preset model is used to process the first current and the second current; the preset model corresponds to a first voltage; the first voltage is the voltage in the direct axis direction of the motor; The determining unit is used to determine the second voltage based on the first current, the second current, and the preset model; the second voltage is the voltage in the quadrature axis direction of the motor; A discharge unit for rapidly discharging according to the second voltage; The second acquisition unit is further configured to acquire a preset capacitor voltage-direct axis voltage curve; the preset capacitor voltage-direct axis voltage curve is a smooth curve; the horizontal axis of the preset capacitor voltage-direct axis voltage curve is used to represent the voltage in the direct axis direction of the motor, and the vertical axis is used to represent the capacitor voltage; the second acquisition unit is further configured to acquire a preset voltage; the preset voltage is the capacitor voltage in the motor controller; and a first voltage is determined based on the preset voltage and the preset capacitor voltage-direct axis voltage curve. The second acquisition unit is specifically used for: In response to the motor's output torque being 0, the mapping relationship between the second voltage and the first voltage, the first current, and the second current is obtained; A preset model is obtained based on the mapping relationship between the second voltage and the first voltage, the first current, and the second current.

5. The apparatus according to claim 4, characterized in that, The device further includes: The inverse Parker transformation module is used to perform inverse Parker transformation on the first voltage and the second voltage. The generation module is used to input the processed first voltage and second voltage to the space vector pulse width modulation unit and generate a pulse width modulation signal; The discharge module is used to control the three-phase inverter to drive the motor according to the pulse width modulation signal, so as to perform rapid discharge of the motor.

6. A computer device comprising a memory and a processor; the memory storing computer-readable instructions, which, when executed by the processor, cause the processor to perform the rapid discharge method as described in any one of claims 1 to 3.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores an implementation program for a fast discharge device, which, when executed by a processor, implements the fast discharge method as described in any one of claims 1 to 3.

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