Method, apparatus, device and storage medium for controlling bus voltage

Abstract

The present application relates to the technical field of high-voltage capacitor rapid discharge of automobiles, and more particularly to a method and device for controlling bus voltage, computer equipment and computer storage medium. The method comprises: in response to an active discharge instruction for the bus capacitor, obtaining real-time motor speed and bus voltage; if the motor speed is greater than the speed safety threshold, determining the phase current reference value based on the voltage stabilization coefficient, the motor phase voltage limit equation and the phase current limit equation, wherein the voltage stabilization coefficient is determined based on the bus voltage and the preset bus voltage limit value; and adjusting the motor AC and DC currents using the phase current reference value until the motor speed is less than or equal to the speed safety threshold.

Description

Technical Field

[0001] This invention relates to the field of high-voltage capacitor rapid discharge technology for automobiles, and more specifically to a method, apparatus, computer equipment, and computer storage medium for controlling bus voltage. Background Technology

[0002] Since the bus voltage of an electric drive system is generally much higher than the voltage that the human body can withstand, in order to avoid injury to the human body when the car stops or in an emergency (e.g., a collision), it is necessary to quickly reduce the bus voltage to a safe voltage (e.g., below 60V) through an active discharge strategy targeting the bus capacitor.

[0003] Currently, commonly used active discharge strategies can be divided into three categories: active discharge strategies based on bleed resistor losses, active discharge strategies based on inverter losses, and active discharge strategies based on motor winding losses. Active discharge strategies based on bleed resistors require additional auxiliary circuitry, which increases the size, weight, and cost of the electric drive system. Active discharge strategies based on inverter losses may generate torque and current oscillations at the beginning of discharge, especially during high-speed motor operation, and these strategies may adversely affect the lifespan of inverter power devices. Active discharge strategies based on motor windings are generally implemented by providing a large direct-axis current; however, when the bus voltage drops to a certain level while the motor speed remains high, improper selection of the discharge current reference value may lead to unstable current control or even malfunctions, causing the bus voltage to recharge above the safe voltage. Furthermore, there are currently few active discharge strategies based on motor windings applicable across the entire speed range. Some existing solutions use two proportional-integral (PI) controllers to obtain AC and DC-axis current references during the voltage regulation phase; however, this dual-PI controller design increases control complexity, and the PI parameters are difficult to adjust, resulting in significant bus voltage fluctuations. Summary of the Invention

[0004] To address or at least alleviate one or more of the above problems, the present invention proposes a method, apparatus, computer device, and computer storage medium for controlling bus voltage, which enables simple and efficient control of bus voltage without the addition of additional auxiliary circuitry or power devices.

[0005] According to a first aspect of the present invention, a method for controlling bus voltage is provided, comprising: A) acquiring real-time motor speed and bus voltage in response to an active discharge command for a bus capacitor; B) if the motor speed is greater than a speed safety threshold, determining a phase current reference value based on a voltage regulation coefficient, a motor phase voltage limit equation, and a phase current limit equation, wherein the voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit value; and C) adjusting the AC and DC currents of the motor using the phase current reference value until the motor speed is less than or equal to the speed safety threshold.

[0006] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, the rotational speed safety threshold is determined at least based on the phase voltage safety threshold or the bus voltage safety threshold.

[0007] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, the voltage regulation coefficient k determined based on the bus voltage and the preset bus voltage limit value satisfies the following formula:

[0008]

[0009] Among them, V dc V represents the real-time bus voltage. l To preset the lower limit of the bus voltage, V u This is the preset upper limit value for bus voltage.

[0010] As an alternative or supplement to the above solution, in a method according to an embodiment of the present invention, step B includes: B1, determining the current current limit amplitude using the motor phase voltage limit equation and the phase current limit equation; and B2, determining the phase current reference value based on the voltage regulation coefficient and the current current limit amplitude.

[0011] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, if the motor is a permanent magnet synchronous motor, then the current current limit amplitude satisfies the following formula:

[0012]

[0013]

[0014] Among them, i dmax i qmax These are the limiting amplitudes of the direct and quadrature axis currents, λ. m For permanent magnet flux linkage, L d For direct-axis inductors, MI ref V is the reference value for the modulation coefficient. dc For real-time bus voltage, ω e L is the motor speed. q For quadrature axis inductance, imax This represents the maximum value of the phase current.

[0015] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, step B2 includes one of the following: determining a first quadrature-axis current reference value based on the voltage regulation coefficient and the quadrature-axis current limit amplitude, and determining a first direct-axis current reference value based on the motor phase voltage limit equation and the first quadrature-axis current reference value; determining a second direct-axis current reference value based on the voltage regulation coefficient and the direct-axis current limit amplitude, and determining a second quadrature-axis current reference value based on the motor phase voltage limit equation and the second direct-axis current reference value; and determining a third direct-axis and quadrature-axis current reference value based on the voltage regulation coefficient and the direct-axis and quadrature-axis current limit amplitudes.

[0016] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, if the motor is a permanent magnet synchronous motor, then the first quadrature axis current reference value i qstable,1 and the first direct-axis current reference value i dstable,1 Satisfy the following formula:

[0017]

[0018]

[0019] Where k is the voltage regulation coefficient, MI ref V is the reference value for the modulation coefficient. dc For real-time bus voltage, ω e L is the motor speed. q For quadrature axis inductance, λ m For permanent magnet flux linkage, L d It is a direct-axis inductor.

[0020] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, if the motor is a permanent magnet synchronous motor, then the second direct-axis current reference value i dstable,2 and the second quadrature axis current reference value i qstable,2 Satisfy the following formula:

[0021]

[0022]

[0023] Where, λ m For permanent magnet flux linkage, L d For direct-axis inductance, k is the voltage regulation coefficient, MI ref V is the reference value for the modulation coefficient. dc For real-time bus voltage, ω e L is the motor speed. q It is a quadrature axis inductor.

[0024] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, if the motor is a permanent magnet synchronous motor, then the third direct-axis current reference value i dstable,3 and the third cross-axis current reference value i qstable,3 Satisfy the following formula:

[0025]

[0026]

[0027] Where, λ m For permanent magnet flux linkage, L d For direct-axis inductance, k is the voltage regulation coefficient, MI ref V is the reference value for the modulation coefficient. dc For real-time bus voltage, ω e L is the motor speed. q It is a quadrature axis inductor.

[0028] As an alternative or supplement to the above solutions, in a method according to an embodiment of the present invention, the phase current reference value includes a fast discharge current reference value for the fast discharge phase and a regulated current reference value for the regulated discharge phase, and step C includes: C1, adjusting the AC and DC currents of the motor using the fast discharge current reference value until the bus voltage drops to a safe bus voltage threshold; C2, adjusting the AC and DC currents of the motor using the regulated current reference value to maintain the bus voltage within a set limit range until the motor speed is less than or equal to the safe speed threshold.

[0029] According to a second aspect of the present invention, a bus voltage control device is provided, comprising: a data acquisition module, configured to acquire real-time motor speed and bus voltage in response to an active discharge command for a bus capacitor; and a discharge control module, configured to: determine a phase current reference value based on a voltage regulation coefficient, a motor phase voltage limit equation, and a phase current limit equation when the motor speed is greater than a speed safety threshold, wherein the voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit value; and adjust the AC and DC currents of the motor using the phase current reference value until the motor speed is less than or equal to the speed safety threshold.

[0030] According to a third aspect of the present invention, a computer device is provided, comprising: a memory; a processor; and a computer program stored in the memory and executable on the processor, wherein execution of the computer program causes any one of the methods described according to the first aspect of the present invention to be performed.

[0031] According to a fourth aspect of the present invention, a computer storage medium is provided, the computer storage medium including instructions that, when executed, perform any one of the methods described according to a first aspect of the present invention.

[0032] The bus voltage control scheme according to one or more embodiments of the present invention can achieve bus voltage control in a simple and efficient manner without adding additional auxiliary circuits or power devices, and can be directly applied to existing three-phase AC motor drive system products. Furthermore, the discharge process according to one or more embodiments is free of torque and current oscillations, and without voltage recharging, thereby achieving rapid and stable discharge of the bus capacitor. Moreover, the bus voltage control scheme according to one or more embodiments of the present invention is applicable to both normal and emergency situations of vehicles, i.e., applicable to the full speed range of the motor. Attached Figure Description

[0033] The above and / or other aspects and advantages of the present invention will become clearer and more readily understood from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are denoted by the same reference numerals. In the drawings:

[0034] Figure 1 A flowchart of a method 10 for controlling bus voltage according to one or more embodiments of the present invention;

[0035] Figure 2 A flowchart of a method 20 for controlling bus voltage according to one or more embodiments of the present invention;

[0036] Figure 3 A block diagram of a bus voltage control device 30 according to one or more embodiments of the present invention; and

[0037] Figure 4 This is a block diagram of a computer device 40 according to one or more embodiments of the present invention. Detailed Implementation

[0038] The following detailed description is merely exemplary in nature and is not intended to limit the disclosed technology or its application and use. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing technical fields, background art, or the following detailed description.

[0039] In the following detailed description of the embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the disclosed technology. However, it will be apparent to those skilled in the art that the disclosed technology can be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0040] Terms such as "comprising" and "including" indicate that, in addition to the units and steps that are directly and explicitly stated in the specification, the technical solution of the present invention does not exclude the presence of other units and steps that are not directly or explicitly stated. Terms such as "first" and "second" do not indicate the order of the units in terms of time, space, size, etc., but are merely used to distinguish the units.

[0041] In the following, various exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0042] Figure 1 This is a flowchart of a method 10 for controlling bus voltage according to one or more embodiments of the present invention.

[0043] like Figure 1 As shown, in step S110, in response to an active discharge command for the bus capacitor, real-time motor speed and bus voltage are acquired. For example, the aforementioned active discharge command is an active discharge request issued by the vehicle controller to enable the active discharge process for the inverter bus capacitor.

[0044] Optionally, after receiving an active discharge command, the real-time bus voltage is first acquired, and it is determined whether the bus voltage is higher than a bus voltage safety threshold. For example, the bus voltage safety threshold can be set to 60V or 40V. If the real-time bus voltage is higher than the bus voltage safety threshold, the active discharge condition is considered met, and the real-time motor speed is further acquired.

[0045] In step S120, if the motor speed is greater than the speed safety threshold, a phase current reference value is determined based on the voltage regulation coefficient, the motor phase voltage limit equation, and the phase current limit equation. Optionally, step S120 includes sub-steps S121-S125.

[0046] Optionally, in step S121, the speed safety threshold is determined at least based on the phase voltage safety threshold or the bus voltage safety threshold. For example, taking a permanent magnet synchronous motor as an example, the speed safety threshold ω can be calculated using the following formula. safe :

[0047]

[0048] Where, λ m For permanent magnet flux linkage, N p V is the number of pole pairs of the motor. phsafe This is the phase voltage safety threshold. For the space vector modulation strategy, the phase voltage safety threshold V... phsafe It can be simplified to:

[0049]

[0050] Among them, V safe This is the bus voltage safety threshold.

[0051] Optionally, after determining the speed safety threshold, in step S122, it is determined whether the motor speed is greater than the determined speed safety threshold.

[0052] Optionally, if the motor speed exceeds the determined safe speed threshold, then in step S123, a voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit. In one example, the determined voltage regulation coefficient k satisfies the following formula:

[0053]

[0054] Among them, V dc V represents the real-time bus voltage. l To preset the lower limit of the bus voltage, V u This is a preset upper limit value for the bus voltage. For example, V l For and V u It can be set to 35V and 45V respectively.

[0055] Optionally, in S124, the current current limit amplitude (e.g., direct and quadrature axis current limit amplitudes) is determined using the motor phase voltage limit equation and phase current limit equation.

[0056] The following explanation uses a permanent magnet synchronous motor as an example to illustrate the process of determining the current limit amplitude. The motor phase current limit equation and phase voltage limit equation can be expressed as follows:

[0057]

[0058]

[0059] Among them, i d For direct-axis current, i q For quadrature-axis current, i max The maximum value of the phase current, u d For direct-axis voltage, u q R is the quadrature axis voltage. s L is the resistance of the motor windings. q It is a quadrature axis inductor.

[0060] If the voltage drop across the motor winding resistance is ignored, the direct-axis current limit amplitude i can be derived from equations 4 and 5 above. dmax Cross-axis current limit amplitude i qmax The following formula should be satisfied:

[0061]

[0062]

[0063] It should be noted that the bus voltage control scheme according to the present invention can be applied to other types of AC motors using the same or similar principles, and the examples and embodiments shown should be considered illustrative rather than limiting. Furthermore, the method for determining the current current limit amplitude applicable to other motors can be deduced similarly.

[0064] Optionally, in step S125, a phase current reference value is determined based on the voltage regulation coefficient determined in step S123 and the current limit amplitude determined in step S124. For example, this document provides three methods for determining the phase current reference value: (Method 1) determining a first quadrature-axis current reference value based on the voltage regulation coefficient and the quadrature-axis current limit amplitude, and determining a first direct-axis current reference value based on the motor phase voltage limit equation and the first quadrature-axis current reference value; (Method 2) determining a second direct-axis current reference value based on the voltage regulation coefficient and the direct-axis current limit amplitude, and determining a second quadrature-axis current reference value based on the motor phase voltage limit equation and the second direct-axis current reference value; and (Method 3) determining a third direct-axis and quadrature-axis current reference values ​​based on the voltage regulation coefficient and the direct-axis and quadrature-axis current limit amplitudes. It should be noted that the phase current reference value determined using any of the above three methods can be used in the active discharge process, and the specific method can be selected according to the discharge time requirements, negative torque limitations, and bus voltage fluctuations.

[0065] The following section will continue to use permanent magnet synchronous motors as an example to explain the three methods for determining the current current limit amplitude.

[0066] Method 1: First, based on the voltage regulation coefficient k and the quadrature axis current limit amplitude i qmax Determine the reference value i of the first quadrature axis current. qstable,1 :

[0067]

[0068] Next, based on the first quadrature-axis current reference value i qstable,1 Based on the motor phase voltage limit equation, determine the reference value i of the first direct-axis current. dstable,1 :

[0069]

[0070] From the above formula, we can know the reference value of the first direct-axis current i. dstable,1 There are two cases where the ± sign in the above formula is -, and the reference value of the first direct-axis current i is... dstable,1 The amplitude is relatively large, the discharge rate is fast, but the negative torque may be relatively large, and the bus voltage fluctuation is relatively large; when the ± sign in the above formula is +, the reference value of the first direct-axis current i dstable,1The amplitude is relatively small, the discharge rate is relatively slow, but the negative torque is smaller, and the bus voltage control is more stable. In practical applications, the specific ± sign can be selected based on the discharge time requirements, negative torque limits, and bus voltage fluctuations.

[0071] Method 2: First, based on the voltage regulation coefficient k and the direct-axis current limit amplitude i dmax Determine the reference value i for the second direct-axis current. dstable,2 :

[0072]

[0073] Here, the selection of the specific ± sign is similar to that in Method 1, and can be determined based on the actual discharge time requirements, negative torque limits, and bus voltage fluctuations.

[0074] Next, based on the second direct-axis current reference value i dstable,2 Based on the motor phase voltage limit equation, determine the reference value i of the second quadrature axis current. qstable,2 :

[0075]

[0076] Method 3: Based on voltage regulation coefficient k and direct-axis current limit amplitude i dmax and the quadrature axis current limit amplitude i qmax Determine the reference value i for the third direct-axis current. dstable,3 and the third cross-axis current reference value i qstable,3 :

[0077]

[0078]

[0079] Here, the selection of the specific ± sign is similar to that in Method 1, and can be determined based on the actual discharge time requirements, negative torque limits, and bus voltage fluctuations.

[0080] It should be noted that the phase current reference values ​​determined in step S120 can be divided into fast discharge current reference values ​​for the fast discharge phase and regulated current reference values ​​for the regulated discharge phase, according to time sequence. It should be understood that in the initial discharge phase, because the bus voltage is very high, it is necessary to quickly reduce the bus voltage to the bus voltage safety threshold according to the fast discharge strategy (i.e., using the fast discharge current reference value); when the bus voltage quickly drops to the bus voltage safety threshold, it is desirable to smoothly maintain the bus voltage within a set limit range according to the regulated discharge strategy (i.e., using the regulated current reference value) until the motor speed is less than or equal to the speed safety threshold. The phase current reference values ​​(e.g., fast discharge current reference values, regulated current reference values) according to one or more embodiments of the present invention can achieve the above-mentioned technical effect of first rapidly reducing voltage and then regulatedly reducing speed.

[0081] Finally, in step S130, the AC and DC currents of the motor are adjusted using the phase current reference value until the motor speed is less than or equal to the speed safety threshold.

[0082] Optionally, step S130 includes: adjusting the AC and DC currents of the motor using a fast discharge current reference value until the bus voltage drops to the bus voltage safety threshold; and adjusting the AC and DC currents of the motor using a regulated current reference value to maintain the bus voltage within a set limit range until the motor speed is less than or equal to the speed safety threshold.

[0083] For example, any common discharge method can be used to discharge the bus capacitor in order to adjust the AC and DC current of the motor using the phase current reference value. Common discharge methods include, but are not limited to, the direct-axis current discharge method based on the winding, the discharge method based on the inverter conduction and switching losses, etc. This article does not impose any specific restrictions on them.

[0084] Method 10 according to one or more embodiments of the present invention can achieve bus voltage control in a simple and efficient manner without adding additional auxiliary circuits or power devices, and can be directly applied to existing three-phase AC motor drive system products. Furthermore, the discharge process according to one or more embodiments is free of torque and current oscillations, and without voltage recharging, thereby achieving rapid and stable discharge of the bus capacitor. Moreover, method 10 is applicable to both normal and emergency situations of a vehicle, i.e., applicable to the full speed range of the motor. In particular, in some embodiments, for vehicle emergency situations (e.g., high-speed collisions), method 10 can quickly (e.g., within milliseconds) reduce the bus voltage to a safe voltage and smoothly maintain the bus voltage within a set limit range until the motor speed drops below a safe speed threshold, thereby achieving the technical effect of rapid voltage reduction followed by stable speed reduction.

[0085] Figure 2 A flowchart of a method 20 for controlling bus voltage according to one or more embodiments of the present invention is shown.

[0086] Step S210: Obtain the real-time motor speed and bus voltage.

[0087] Step S220: Determine whether the motor speed is greater than the safe speed threshold. If the result of step S220 is "yes", continue to step S230; otherwise, proceed to step S260. The process for determining the safe speed threshold can be found in the description of step S120 above, and will not be repeated here.

[0088] Step S230: Based on the voltage regulation coefficient, the motor phase voltage limit equation, and the phase current limit equation, determine the phase current reference value. The voltage regulation coefficient is determined based on the bus voltage and the preset bus voltage limit value. The process for determining the phase current reference value can be found in the description of step S120 above, and will not be repeated here.

[0089] Step S240: Adjust the AC and DC currents of the motor using the phase current reference value, and obtain the real-time motor speed and bus voltage.

[0090] Step S250: Determine whether the motor speed is lower than the safe speed threshold. If the result of step S250 is "yes", then continue to step S260; otherwise, return to step S230.

[0091] Step S260: Discharge the bus capacitor until the discharge is complete.

[0092] Figure 3 This is a block diagram of a bus voltage control device 30 according to one or more embodiments of the present invention. Figure 3 As shown, the control device 30 includes a data acquisition module 310 and a discharge control module 320.

[0093] The data acquisition module 310 is configured to acquire real-time motor speed and bus voltage in response to an active discharge command for the bus capacitor.

[0094] The discharge control module 320 is configured to determine a phase current reference value based on the voltage regulation coefficient, the motor phase voltage limit equation, and the phase current limit equation when the motor speed exceeds the speed safety threshold. The voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit value. The module also uses the phase current reference value to adjust the motor's AC and DC currents until the motor speed is less than or equal to the speed safety threshold. The determination of the phase current reference value and the current adjustment process using it can be found in the description of steps S120-S130 above, and will not be repeated here.

[0095] Continue to refer to Figure 4 , Figure 4 This is a block diagram of a computer device 40 according to one or more embodiments of the present invention.

[0096] like Figure 4 As shown, the computer device 40 includes a communication unit 410, a memory 420, a processor 430, and a computer program 440 stored in the memory 420 and executable on the processor 430.

[0097] The communication unit 410 serves as a communication interface and is configured to establish a communication connection between a computer device and an external device (e.g., a current controller, a motor sensor) or a network.

[0098] Memory 420 stores a computer program 440 that can be executed by processor 430. Processor 430 is configured to execute computer program 440 to perform, for example, Figure 1 or Figure 2 The method shown.

[0099] According to a fourth aspect of the invention, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements as follows: Figure 1 or Figure 2 The method shown. The computer-readable storage medium may include random access memory (RAM) (such as synchronous dynamic random access memory (SDRAM)), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, and other known storage media.

[0100] Where applicable, the various embodiments provided by the present invention may be implemented using hardware, software, or a combination of hardware and software. Furthermore, where applicable, without departing from the scope of the invention, the various hardware and / or software components described herein may be combined into composite components comprising software, hardware, and / or both. Where applicable, without departing from the scope of the invention, the various hardware and / or software components described herein may be divided into sub-components comprising software, hardware, or both. Additionally, where applicable, it is contemplated that software components may be implemented as hardware components, and vice versa.

[0101] The software (such as program code and / or data) according to the invention can be stored on one or more computer storage media. It is also contemplated that the software identified herein can be implemented using one or more networked and / or otherwise general-purpose or special-purpose computers and / or computer systems. Where applicable, the order of the various steps described herein can be changed, combined into compound steps, and / or divided into sub-steps to provide the features described herein.

[0102] The embodiments and examples presented herein are provided to best illustrate embodiments of the invention and its particular applications, thereby enabling those skilled in the art to practice and use the invention. However, those skilled in the art will understand that the above description and examples are provided merely for ease of illustration and example. The descriptions presented are not intended to cover all aspects of the invention or to limit the invention to the precise forms disclosed.

Claims

1. A method for controlling bus voltage, characterized in that, include: A. In response to the active discharge command for the bus capacitor, obtain the real-time motor speed and bus voltage; B. If the motor speed is greater than the speed safety threshold, then based on the voltage regulation coefficient, the motor phase voltage limit equation, and the phase current limit equation, a phase current reference value is determined. The voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit value. Step B includes: B1. Using the aforementioned motor phase voltage limit equation and phase current limit equation, determine the current limit amplitude; and B2. Based on the voltage regulation coefficient and the current current limit amplitude, determine the phase current reference value; and C. Adjust the AC and DC currents of the motor using the phase current reference values ​​until the motor speed is less than or equal to the speed safety threshold, wherein the phase current reference values ​​include a fast discharge current reference value for the fast discharge phase and a regulated current reference value for the regulated discharge phase, and step C includes: C1. Adjust the AC and DC currents of the motor using the fast discharge current reference value until the bus voltage drops to the bus voltage safety threshold. C2. The AC and DC currents of the motor are adjusted using the regulated current reference value to maintain the bus voltage within the set limit range until the motor speed is less than or equal to the speed safety threshold.

2. The method according to claim 1, wherein, The rotational speed safety threshold is determined based at least on the phase voltage safety threshold or the bus voltage safety threshold.

3. The method according to claim 1, wherein, The voltage regulation coefficient determined based on the bus voltage and the preset bus voltage limit value. Satisfy the following formula: in, This is the real-time bus voltage. To preset the lower limit value of the bus voltage, This is the preset upper limit value for bus voltage.

4. The method according to claim 1, wherein, If the motor is a permanent magnet synchronous motor, then the current current limit amplitude satisfies the following formula: in, , These are the limiting amplitudes of the direct-axis and quadrature-axis currents, respectively. It is a permanent magnet flux linkage. It is a direct-axis inductor. This is a reference value for the modulation coefficient. This is the real-time bus voltage. This refers to the motor speed. It is a quadrature axis inductor. This represents the maximum value of the phase current.

5. The method according to claim 1, wherein, Step B2 includes one of the following: The first cross-axis current reference value is determined based on the voltage regulation coefficient and the cross-axis current limit amplitude, and the first straight-axis current reference value is determined based on the motor phase voltage limit equation and the first cross-axis current reference value. The second direct-axis current reference value is determined based on the voltage regulation coefficient and the direct-axis current limit amplitude, and the second quadrature-axis current reference value is determined based on the motor phase voltage limit equation and the second direct-axis current reference value; as well as The third direct and quadrature axis current reference values ​​are determined based on the voltage regulation coefficient and the limiting amplitudes of the direct and quadrature axis currents.

6. The method according to claim 5, wherein, If the motor is a permanent magnet synchronous motor, then the first quadrature axis current reference value and the first direct-axis current reference value Satisfy the following formula: in, This is the voltage regulation coefficient. This is a reference value for the modulation coefficient. This is the real-time bus voltage. This refers to the motor speed. It is a quadrature axis inductor. It is a permanent magnet flux linkage. It is a direct-axis inductor.

7. The method according to claim 5, wherein, If the motor is a permanent magnet synchronous motor, then the second direct-axis current reference value and the second cross-axis current reference value Satisfy the following formula: in, It is a permanent magnet flux linkage. It is a direct-axis inductor. This is the voltage regulation coefficient. This is a reference value for the modulation coefficient. This is the real-time bus voltage. This refers to the motor speed. It is a quadrature axis inductor.

8. The method according to claim 5, wherein, If the motor is a permanent magnet synchronous motor, then the third direct-axis current reference value and the third cross-axis current reference value Satisfy the following formula: in, It is a permanent magnet flux linkage. It is a direct-axis inductor. This is the voltage regulation coefficient. This is a reference value for the modulation coefficient. This is the real-time bus voltage. This refers to the motor speed. It is a quadrature axis inductor.

9. A bus voltage control device, characterized in that, include: The data acquisition module is used to acquire real-time motor speed and bus voltage in response to the active discharge command for the bus capacitor; The discharge control module is used for: When the motor speed exceeds a safe speed threshold, a phase current reference value is determined based on the voltage regulation coefficient, the motor phase voltage limit equation, and the phase current limit equation. The voltage regulation coefficient is determined based on the bus voltage and a preset bus voltage limit value. Determining the phase current reference value includes: B1. Using the aforementioned motor phase voltage limit equation and phase current limit equation, determine the current limit amplitude; and B2. Based on the voltage regulation coefficient and the current current limit amplitude, determine the phase current reference value; and The AC and DC currents of the motor are adjusted using the phase current reference value until the motor speed is less than or equal to the speed safety threshold. The phase current reference value includes a fast discharge current reference value for the fast discharge phase and a regulated current reference value for the regulated discharge phase. Adjusting the AC and DC currents of the motor using the phase current reference value includes: C1. Adjust the AC and DC currents of the motor using the fast discharge current reference value until the bus voltage drops to the bus voltage safety threshold. C2. The AC and DC currents of the motor are adjusted using the regulated current reference value to maintain the bus voltage within the set limit range until the motor speed is less than or equal to the speed safety threshold.

10. A computer device, characterized in that, It comprises: a memory; a processor; and a computer program stored in the memory and executable on the processor, the execution of which causes the method according to any one of claims 1-8 to be performed.

11. A computer storage medium, characterized in that, The computer storage medium includes instructions that, when executed, perform the method according to any one of claims 1-8.

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