Motor driver bus overvoltage suppression method and device

Abstract

The invention relates to the technical field of permanent magnet synchronous motors, and discloses a motor driver bus overvoltage suppression method and device, which can realize efficient and reliable bus overvoltage suppression while ensuring the operation performance of a motor through the collaborative design of a sliding-mode observer and d-axis current compensation. The core of the method is to dynamically monitor the measured value and the limit value of the bus voltage based on the sliding-mode observer, the inherent strong robustness of sliding-mode control can effectively resist disturbance under the working conditions of motor load fluctuation, abrupt change of rotating speed and the like, and the tiny rising trend of the bus voltage is accurately captured; and an adaptive d-axis compensation current instruction is quickly generated, so that overvoltage threshold breakthrough caused by response lag in a traditional overvoltage suppression method is avoided, and further rise of the bus voltage is blocked in time.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motor technology, specifically to a method and apparatus for suppressing overvoltage on the motor driver bus. Background Technology

[0002] In fields such as industrial drives, new energy vehicles, and servo systems, permanent magnet synchronous motors have become mainstream drive components due to their advantages of high efficiency, high power density, and high dynamic response. However, when the motor is in braking or deceleration mode, its rotor continues to rotate due to inertia. At this time, the motor will switch to the generator mode and feed electrical energy back to the DC bus through the inverter (i.e., the "energy feeding phenomenon").

[0003] DC buses are typically connected in parallel with capacitors to stabilize voltage. When the electrical energy generated by the power feed exceeds the capacitor's absorption capacity and cannot be released in time, the bus voltage will rise rapidly. If the voltage exceeds the driver's safety threshold, it will directly trigger an overvoltage protection fault, causing the system to shut down. In severe cases, it may even damage the inverter's power devices, affecting the equipment's operational reliability and lifespan. To address this issue, the industry has developed three typical solutions: external braking resistor solutions, speed planning solutions, and motor loss-based solutions based on PI controllers. However, existing solutions have shortcomings in terms of size, dynamic performance, control effect, and stability, making it difficult to achieve a balance. There is an urgent need to explore better power feed suppression and bus voltage stabilization technologies to meet the high performance and high reliability requirements of permanent magnet synchronous motors in different application scenarios. Summary of the Invention

[0004] In view of this, the present invention provides a method and apparatus for suppressing overvoltage on a motor driver bus, in order to solve the problem of how to suppress overvoltage on the bus.

[0005] In a first aspect, the present invention provides a method for suppressing overvoltage on a motor driver bus, comprising: obtaining a d-axis compensation current command using a sliding mode observer based on a measured bus voltage value and a bus voltage limit; obtaining a d-axis reference current command by compensating a preset d-axis current command in the closed-loop control of the motor using the d-axis compensation current command; and performing closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command.

[0006] In one optional implementation, the process of obtaining the d-axis compensation current command includes: taking the difference between the bus voltage limit and the measured bus voltage as the bus voltage error; calculating the motor electromagnetic power using a saturation function based on the bus voltage error; and calculating the d-axis current command based on the motor electromagnetic power.

[0007] In one alternative implementation, before calculating the electromagnetic power of the motor using the saturation function, the method further includes limiting the bus voltage error.

[0008] In one alternative implementation, the saturation function is valid when it is greater than 0.

[0009] In one optional implementation, the formula for calculating the electromagnetic power of the motor using the saturation function is as follows:

[0010]

[0011] in, Pe This refers to the electromagnetic power of the motor. C This refers to the system capacitor value; U This is the capacitor voltage; K This is an adjustable gain parameter; sign ( s ) is a saturation function; V ref For bus voltage limits; V bus This is the measured value of the bus voltage.

[0012] In one optional implementation, the process of obtaining the d-axis reference current command includes: using a speed control loop to calculate a preset d-axis current command and a preset q-axis current command; and using the sum of the preset d-axis current command and the d-axis compensation current command as the d-axis reference command.

[0013] In one optional implementation, the process of performing closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command includes: using a preset q-axis current command as the q-axis reference current command; calculating the d-axis current measurement value and the q-axis current measurement value using a current control loop based on the three-phase voltage of the motor; and inputting the difference between the d-axis reference current command and the d-axis current measurement value, and the difference between the q-axis reference current command and the q-axis current measurement value, into the voltage loop to obtain... αβ Under-axis reference voltage command; according to αβ The reference voltage command under the shaft is used to obtain the switching signal of the voltage converter using a preset modulation method.

[0014] Secondly, the present invention provides a motor driver bus overvoltage suppression device, the device comprising: a sliding mode observation module for obtaining a d-axis compensation current command based on the measured bus voltage value and the bus voltage limit using a sliding mode observer; a compensation module for obtaining a d-axis reference current command after compensating a preset d-axis current command in the closed-loop control of the motor using the d-axis compensation current command; and a closed-loop control module for performing closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command.

[0015] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the motor driver bus overvoltage suppression method described in the first aspect or any corresponding embodiment thereof.

[0016] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the motor driver bus overvoltage suppression method described in the first aspect or any corresponding embodiment thereof.

[0017] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the motor driver bus overvoltage suppression method described in the first aspect or any corresponding embodiment thereof.

[0018] This invention, through the collaborative design of a sliding mode observer and d-axis current compensation, can achieve efficient and reliable bus overvoltage suppression while ensuring motor operating performance, possessing multiple technical advantages: its core lies in relying on the sliding mode observer to dynamically monitor the measured and limited values ​​of the bus voltage. The inherent robustness of sliding mode control can effectively resist disturbances under operating conditions such as motor load fluctuations and sudden speed changes, accurately capture the slight upward trend of the bus voltage, and quickly generate a suitable d-axis compensation current command, avoiding the overvoltage threshold breakthrough caused by response lag in traditional overvoltage suppression methods, thereby timely blocking further increases in bus voltage.

[0019] This invention focuses the d-axis compensation current command on compensating for the preset d-axis current command. It achieves overvoltage suppression only by adjusting the d-axis current related to motor excitation, without interfering with the q-axis current responsible for torque output. This ensures that the motor can still stably track torque demand during overvoltage suppression, avoiding problems such as torque pulsation and speed drop that affect load operation. It is especially suitable for industrial drive and servo control scenarios with high requirements for torque stability.

[0020] This invention eliminates the need for additional hardware circuits such as unloading resistors and voltage clamps. It integrates into the existing closed-loop control system solely through software algorithm optimization. This reduces hardware costs and circuit complexity while avoiding energy losses associated with traditional hardware unloading methods, thus improving the overall energy efficiency of the driver. Furthermore, the entire suppression process is deeply coupled with the motor closed-loop control, enabling overvoltage mitigation without interrupting normal motor operation. This ensures the continuity and smoothness of system operation and effectively adapts to various complex operating conditions that can easily lead to bus overvoltage, such as motor start-stop, high-speed field weakening, and sudden load unloading. This significantly improves the operational reliability and environmental adaptability of the motor drive system. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic flowchart of a method for suppressing overvoltage on a motor driver bus according to an embodiment of the present invention; Figure 2 This is a structural diagram of the acquisition circuit according to an embodiment of the present invention; Figure 3 This is a control block diagram for obtaining the d-axis current command according to an embodiment of the present invention; Figure 4 This is a control block diagram of a motor driver bus overvoltage suppression method according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0024] The three typical solutions are: external braking resistor solution, speed planning solution, and motor loss solution based on PI controller, as detailed below: 1. External braking resistor solution This solution is the mainstream choice for most current drives. Its core principle is to connect a braking unit and a braking resistor in parallel on the DC bus: when the bus voltage reaches a set threshold, the braking unit turns on, guiding excess feed energy to the braking resistor, where the energy is dissipated through resistor heating, thereby suppressing the rise in bus voltage. However, this solution requires additional braking resistor and braking unit configuration, which not only increases the overall size and installation space requirements of the drive, but also has energy loss and heat dissipation problems due to resistor heating, especially limiting its applicability in compact equipment or high feed energy scenarios.

[0025] 2. Speed ​​Planning Scheme Some research and applications have optimized the speed curve planning during motor braking to slow down the rate of speed decrease and reduce the energy feed intensity per unit time, thereby reducing bus voltage fluctuations. For example, an S-curve or segmented deceleration strategy can be used to avoid concentrated energy feed caused by a sudden drop in speed. However, to achieve effective voltage suppression, an overly flat speed curve needs to be designed, which significantly prolongs the motor braking time. In scenarios with high dynamic response requirements (such as servo positioning and emergency braking of automobiles), an excessively long braking time will directly affect the system's operational accuracy and safety performance, making it difficult to balance voltage stability and dynamic response requirements.

[0026] 3. Motor loss scheme based on PI controller To address the energy feed problem, another approach proposes closed-loop regulation of the bus voltage by controlling motor losses: using a linear PI (proportional-integral) controller, the copper and iron losses of the motor are adjusted based on the bus voltage deviation, converting excess feed energy into internal motor losses and thus stabilizing the bus voltage. However, it's important to note that the system consisting of the motor's power transmission and the DC bus capacitor voltage is inherently a nonlinear system. Its characteristics dynamically change with operating parameters such as motor speed, load, and temperature. The parameter design of the linear PI controller relies on a linearized model of the system, making it difficult to adapt to the nonlinear characteristics under fluctuating operating conditions, leading to deviations from the ideal control effect. Furthermore, the stability analysis of nonlinear systems requires complex nonlinear theory support, which cannot be directly applied using traditional linear control theory, increasing the design difficulty and reliability risks of the proposed solution.

[0027] The energy feeding phenomenon generated during braking of a permanent magnet synchronous motor is essentially due to the inability of the electrical energy converted from the rotor's inertial rotation to be consumed or stored by the system in a timely manner, leading to an abnormal increase in the DC bus capacitor voltage. In traditional solutions, the braking resistor, as a "passive energy dissipation component," needs to be converted into resistive heat energy through an additional hardware circuit to alleviate the pressure on the bus voltage. However, this embodiment innovatively adopts an "active loss control" strategy, shifting the core of energy feeding absorption from "external hardware" to "motor self-loss regulation." By precisely controlling the iron and copper losses during motor operation, the excess electrical energy generated during braking is directly converted into controllable internal losses of the motor, achieving an energy balance between "energy feeding" and "losses." This prevents the bus voltage from rising due to energy accumulation at the source, completely breaking the dependence on the additional hardware of the braking resistor.

[0028] Based on the above, according to an embodiment of the present invention, an embodiment of a method for suppressing overvoltage on a motor driver bus is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0029] Figure 1 This is a flowchart of a motor driver bus overvoltage suppression method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S1: Based on the measured bus voltage value and the bus voltage limit, obtain the d-axis compensation current command using a sliding mode observer.

[0030] Specifically, since the bus voltage greatly exceeds the voltage that the processor port can withstand, where the processor can be an MCU, therefore... Figure 2 The voltage divider circuit shown acquires real-time bus voltage measurements. V bus .because V ADC This can be detected via an analog port, and the result can be obtained using the resistor voltage divider rule: (1) Specifically, by acquiring the real-time value of the bus voltage with high precision and comparing it with the pre-set bus voltage safety limit, the voltage deviation is obtained; then, the sliding mode observer is used to construct the mapping relationship of "voltage deviation-current regulation", and finally the d-axis compensation current command for suppressing bus overvoltage is generated.

[0031] Compared to traditional linear PI controllers, sliding mode observers can directly adapt to the nonlinear characteristics of "power-capacitor voltage" without relying on a linearized system model. This fundamentally solves the problems of "poor control effect and difficulty in stability analysis of linear controllers" in the background technology. Even if motor parameters (such as resistance and inductance) or load fluctuate, it can still maintain stable voltage regulation capability.

[0032] By leveraging the fast approach characteristics of the sliding mode observer, a d-axis compensation current command can be quickly generated after a voltage deviation occurs, avoiding bus voltage overshoot caused by the lag in response of traditional controllers and effectively reducing the risk of driver-triggered overvoltage faults.

[0033] Step S2: After compensating the preset d-axis current command in the closed-loop control of the motor with the d-axis compensation current command, the d-axis reference current command is obtained.

[0034] Specifically, the preset d-axis current command is generated based on the normal operating requirements of the motor (such as efficiency optimization and field weakening control), representing the optimal excitation current when there is no risk of power feeding. The d-axis compensation current command is superimposed with the preset d-axis current command to obtain a d-axis reference current command that takes into account both "normal drive" and "overvoltage suppression". At the same time, the safety and smoothness of current regulation are ensured through constraints.

[0035] The preset d-axis current command ensures high efficiency during normal motor operation, while the d-axis compensation current command only intervenes when there is a risk of power failure. This avoids the problem of "ignoring voltage safety in order to ensure efficiency" and also prevents the situation of "excessive voltage suppression leading to energy waste", thus achieving a balance between the dual goals of "efficiency and safety".

[0036] Step S3: Perform closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command.

[0037] Specifically, the q-axis reference current command is derived from the motor's torque demand (such as drive and braking torque) and represents the motor's power output target. Combined with the d-axis reference current command obtained in step S2, a closed-loop control is constructed. The inverter is driven by modulation technology to ultimately achieve precise control of the motor current, while the operating status is fed back in real time to dynamically adjust the command.

[0038] In this embodiment, in step S1, the sliding mode observer accurately identifies the energy feed intensity based on the deviation between the measured value and the limit of the bus voltage, and then generates a d-axis compensation current command for adjusting losses. The core function of this command is to dynamically adjust the values ​​of iron loss and copper loss by changing the excitation state of the motor. Secondly, in step S2, the d-axis compensation current command is superimposed with the preset d-axis current command to obtain a d-axis reference current command that takes into account both "normal driving efficiency" and "energy feed loss adjustment", ensuring that loss control will not interfere with the normal torque output of the motor. Finally, in step S3, the d-axis reference current is converted into the actual stator current through the vector control closed loop, so that the motor loss matches the energy feed intensity in real time. The stronger the energy feed, the greater the loss adjustment range, and the excess electrical energy is quickly absorbed, and the bus voltage is always stable within a safe range.

[0039] In some alternative implementations, in order to suppress bus overvoltage by controlling motor losses, a power analysis of the permanent magnet synchronous motor is performed, as follows: According to the torque equation of the SPM (Surface Permanent Magnet) motor shown in equation (2), the copper loss equation shown in equation (3), the mechanical power equation shown in equation (4), and the electromagnetic power equation shown in equation (5), it can be seen that due to d The shaft current needs to provide the motor's running torque, so it can be adjusted... d The electromagnetic power is adjusted by the shaft current.

[0040] (2) in, T e For torque; n p This represents the number of pole pairs of the motor. ψ For permanent magnet flux linkage; I qFor motor q Axis current.

[0041] (3) in, P cu For copper loss; R s The motor resistance; I s It is a current vector.

[0042] (4) in, P me Mechanical power; ω m This refers to the mechanical angular velocity of the motor.

[0043] (5) Based on this, the design analysis of the overvoltage prevention sliding mode observer is as follows: As can be seen from the capacitor charging formulas shown in equations (6) and (7), the capacitor is a nonlinear system under constant power charging.

[0044] (6) (7) in, W To store energy in a capacitor; P e Electromagnetic energy; C is the capacitance value; U is the voltage across the capacitor.

[0045] Differentiating both sides of equation (7) simultaneously, we get: (8) Will P e As input to the sliding mode observer, the formula for the sliding mode observer is: (9) make , U ref Define the desired voltage and define the sliding surface. s = z 1, .

[0046] Define Lyapunov functions Then there is (10) From equation (10), it can be seen that when If the system is stable, then take... (k >0). That is, .

[0047] when s When ≧0, then .

[0048] Similarly, when s When <0, P e > CUks ,make P e =- CUks · sign ( s If the system is stable, then equation (11) must be satisfied.

[0049] (11) Based on this, the process of optionally obtaining the d-axis compensation current command includes: taking the difference between the bus voltage limit and the measured bus voltage as the bus voltage error; calculating the motor electromagnetic power using a saturation function based on the bus voltage error; and calculating the d-axis current command based on the motor electromagnetic power.

[0050] Specifically, refer to Figure 3 The control block diagram shown sets the bus voltage limit. V ref and calculate s =( V ref - V bus Based on the above analysis, the desired electromagnetic power of the motor is calculated. P e =- CUk · sign ( s Because overvoltage protection only applies to... sign ( s When )>0, it is controlled, so a saturation function is used. P e Limit > 0. The expected value obtained subsequently through the controller. P e calculate I d The calculation formula is as follows, where saturation (·) is the amplitude limiting function.

[0051] (12) in, P e This refers to the electromagnetic power of the motor. C This refers to the system capacitor value; U This is the capacitor voltage; K This is an adjustable gain parameter; sign ( s ) is a saturation function; V ref For bus voltage limits; V bus This is the measured value of the bus voltage.

[0052] In some alternative implementations, such as Figure 4 As shown, the process of obtaining the d-axis reference current command includes: calculating the preset d-axis current command using the speed control loop. I sdref and preset q-axis current command I sqref The sum of the preset d-axis current command and the d-axis compensation current command is used as the d-axis reference command.

[0053] Specifically, such as Figure 4 As shown, the actual rotational speed of the motor rotor is collected in real time by position and speed sensing modules (such as photoelectric encoders and Hall sensors) and compared with the target rotational speed set by the control system. n ref The difference is calculated to obtain the "speed deviation Δn" (Δn = target speed - actual speed). The speed deviation Δn is then input to the PI controller of the speed control loop. The controller calculates the deviation based on the preset proportional coefficient (Kp) and integral coefficient (Ki) and outputs a preset d-axis current command. I sdref and preset q-axis current command I sqref .

[0054] In some alternative implementations, such as Figure 4 As shown, the process of closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command includes: using the preset q-axis current command as the q-axis reference current command; and controlling the motor according to the three-phase voltage ( V a , V b , V c ), calculate d-axis current measurement using current control loop I sd and q-axis current measurement value I sq The difference between the d-axis reference current command and the d-axis current measurement, and the difference between the q-axis reference current command and the q-axis current measurement, are input to the voltage loop to obtain... αβ Under-axis reference voltage command ( V sαref , V sβref );according to αβThe reference voltage command under the shaft is used to obtain the switching signal of the voltage converter using a preset modulation method.

[0055] This embodiment also provides a motor driver bus overvoltage suppression device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0056] This embodiment provides a motor driver bus overvoltage suppression device, the device comprising: The sliding mode observation module is used to obtain the d-axis compensation current command based on the measured bus voltage value and the bus voltage limit using the sliding mode observer. The compensation module is used to compensate the preset d-axis current command in the closed-loop control of the motor using the d-axis compensation current command, so as to obtain the d-axis reference current command. The closed-loop control module is used to perform closed-loop control of the motor based on the q-axis reference current command and the d-axis reference current command.

[0057] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0058] In this embodiment, the motor driver bus overvoltage suppression device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0059] This invention also provides a computer device having the above-described motor driver bus overvoltage suppression device.

[0060] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 5As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 5 Take a processor 10 as an example.

[0061] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GPA), or any combination thereof.

[0062] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0063] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0064] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0065] The computer device also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0066] Input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function control of the computer device, such as a touchscreen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touchscreen.

[0067] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0068] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0069] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0070] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method of bus overvoltage suppression for a motor drive, the method comprising: The method comprises the following steps: Based on the bus voltage measurement value and the bus voltage limit value, a d-axis compensation current instruction is obtained by using a sliding mode observer; After the preset d-axis current instruction in the closed-loop control of the motor is compensated by using the d-axis compensation current instruction, a d-axis reference current instruction is obtained; Based on the q-axis reference current instruction and the d-axis reference current instruction, the motor is controlled in a closed loop.

2. The motor drive bus overvoltage suppression method of claim 1, wherein, The process of obtaining the d-axis compensation current instruction comprises: The difference between the bus voltage limit value and the bus voltage measurement value is taken as a bus voltage error; According to the bus voltage error, the motor electromagnetic power is calculated by using a saturation function; The d-axis current instruction is calculated according to the motor electromagnetic power.

3. The motor drive bus overvoltage suppression method of claim 2, wherein, Before the motor electromagnetic power is calculated by using the saturation function, the following step is further included: The bus voltage error is limited in amplitude.

4. The motor drive bus overvoltage suppression method of claim 2, wherein, The saturation function is effective when it is greater than 0.

5. The motor drive bus overvoltage suppression method of claim 4, wherein, The calculation formula for calculating the motor electromagnetic power by using the saturation function is: wherein, P e is the electromagnetic power of the electric machine; C is the system capacitance value; U is the capacitance voltage; K is the adjustable gain parameter; sign s is the saturation function; V ref is the bus voltage limit; V bus is the bus voltage measurement.​ 6. The motor drive bus overvoltage suppression method of claim 1, wherein, The process of obtaining the d-axis reference current instruction comprises: The preset d-axis current instruction and the preset q-axis current instruction are calculated by using a speed control loop; The sum of the preset d-axis current instruction and the d-axis compensation current instruction is taken as the d-axis reference instruction.

7. The motor drive bus overvoltage suppression method of claim 6, wherein, The process of controlling the motor in a closed loop based on the q-axis reference current instruction and the d-axis reference current instruction comprises: The preset q-axis current instruction is taken as the q-axis reference current instruction; According to the three-phase voltage of the motor, the d-axis current measurement value and the q-axis current measurement value are calculated by using a current control loop; The difference between the d-axis reference current command and the d-axis current measurement and the difference between the q-axis reference current command and the q-axis current measurement are input to a voltage loop to obtain αβ a reference voltage command under the d-axis According to the above αβ The reference voltage command under the shaft is used to obtain the switching signal of the voltage converter by a preset modulation method.

8. A motor driver bus overvoltage suppression device, characterized in that, The device comprises: A sliding mode observation module is configured to obtain a d-axis compensation current instruction by using a sliding mode observer based on a bus voltage measurement value and a bus voltage limit value; A compensation module is configured to obtain a d-axis reference current instruction after compensating a preset d-axis current instruction in the closed-loop control of the motor by using the d-axis compensation current instruction; A closed-loop control module is configured to control the motor in a closed loop based on a q-axis reference current instruction and the d-axis reference current instruction.

9. A computer device, comprising: The method comprises the following steps: A memory and a processor are communicatively connected, and the memory stores computer instructions; the processor executes the computer instructions to perform the bus overvoltage suppression method of the motor driver according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for making a computer execute the bus overvoltage suppression method of the motor driver according to any one of claims 1 to 7.

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