Voltage limiting method and related equipment for controller of embedded permanent magnet synchronous motor

Abstract

A voltage limiting method and related equipment for a controller of an embedded permanent magnet synchronous motor, relating to the field of motors. The method comprises: obtaining the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; performing voltage limiting on the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage, wherein the square root of the D-axis voltage and the limited Q-axis voltage is less than the bus voltage of the embedded permanent magnet synchronous motor; and adjusting the torque of the embedded permanent magnet synchronous motor based on the D-axis voltage and the limited Q-axis voltage. The implementation of the technical solution provided by the present invention can improve the performance and stability of the embedded permanent magnet synchronous motor when running at high speed.

Description

Technical Field

[0001] The present invention relates to the field of motor technology, and in particular to a voltage limiting method for a controller of an embedded permanent magnet synchronous motor and related equipment. Background Art

[0002] With the rapid development of the new energy vehicle industry, the interior permanent magnet synchronous motor (IPMSM) has gradually become the first choice for electric vehicle power systems due to its high efficiency and high power density. However, when running at high speeds, the IPMSM faces the challenge of increased back electromotive force, which may cause the motor's line voltage to approach or exceed the DC bus voltage, thereby causing the risk of system current loss of control. Therefore, how to effectively control the output voltage of the IPMSM under high-speed operation has become a key issue in the design of electric vehicle power systems.

[0003] To solve this problem, traditional methods usually use voltage limiting technology. The core of this technology is to ensure that the total output voltage of the motor does not exceed the DC bus voltage by adjusting the D-axis voltage and the Q-axis voltage at the same time. Specifically, the system calculates the output voltage based on the sum of the squares of the D-axis and Q-axis voltages, and scales the voltages of the two axes according to a certain ratio, thereby limiting the output voltage to a safe range. This method can prevent system overvoltage and current runaway to a certain extent.

[0004] However, the traditional voltage limiting method has a significant drawback. Since the D-axis and Q-axis voltages are modified at the same time, this method causes the D-axis current and Q-axis current to change at the same time. Under high-speed operation, this synchronous change may cause current oscillation, making it difficult for the system to remain stable. Summary of the invention

[0005] The present invention provides a voltage limiting method for a controller of an embedded permanent magnet synchronous motor and related equipment, which can improve the performance and stability of the embedded permanent magnet synchronous motor when running at high speed.

[0006] In a first aspect of the present invention, a voltage limiting method for an embedded permanent magnet synchronous motor is provided, comprising: Obtain the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; Based on the D-axis voltage, the Q-axis voltage is voltage-limited to obtain the Q-axis voltage after the voltage limiting, wherein the square root of the D-axis voltage and the Q-axis voltage after the voltage limiting is less than the bus voltage of the embedded permanent magnet synchronous motor; The torque of the embedded permanent magnet synchronous motor is adjusted based on the D-axis voltage and the limited Q-axis voltage.

[0007] Optionally, obtaining the D-axis voltage and the Q-axis voltage of the embedded permanent magnet synchronous motor includes: Obtain the three-phase current and rotor position of the embedded permanent magnet synchronous motor; Determining a D-axis current and a Q-axis current of the embedded permanent magnet synchronous motor based on the three-phase current and the rotor position; The D-axis current is converted into a D-axis voltage, and the Q-axis current is converted into a Q-axis voltage.

[0008] Optionally, the voltage limiting of the Q-axis voltage based on the D-axis voltage is characterized by comprising: Determining a first amplitude limiting range of the D-axis voltage based on a bus voltage of the embedded permanent magnet synchronous motor; In the first limiting range, the Q-axis voltage is limited based on the D-axis voltage.

[0009] Optionally, within the first limiting range, limiting the Q-axis voltage based on the D-axis voltage includes: Determining whether the D-axis voltage exceeds the first limiting range; If the D-axis voltage exceeds the first limiting range, the D-axis voltage is set to a boundary value of the first limiting range, and the Q-axis voltage is set to 0.

[0010] Optionally, within the first limiting range, limiting the Q-axis voltage based on the D-axis voltage includes: If it is determined that the D-axis voltage is within the first amplitude limiting range, a square root of a square difference between the D-axis voltage and the output voltage is used as a second amplitude limiting range of the Q-axis voltage; The Q-axis voltage is limited based on the second limiting range.

[0011] Optionally, limiting the Q-axis voltage based on the second limiting range includes: Determining whether the Q-axis voltage exceeds the second limiting range; If the Q-axis voltage exceeds the second amplitude limiting range, the Q-axis voltage is set to a boundary value of the first amplitude limiting range.

[0012] The present invention also provides a voltage limiting device for an embedded permanent magnet synchronous motor, comprising: A voltage acquisition module is used to obtain the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; a voltage limiting module, configured to perform voltage limiting on the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage, wherein a square root of the D-axis voltage and the limited Q-axis voltage is less than a bus voltage of the embedded permanent magnet synchronous motor; A voltage regulation module is used to regulate the torque of the embedded permanent magnet synchronous motor based on the D-axis voltage and the limited Q-axis voltage.

[0013] In a second aspect of the present invention, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a voltage limiting method for an embedded permanent magnet synchronous motor as described in any one of the above is implemented.

[0014] In a third aspect of the present invention, a non-transitory computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the voltage limiting method of the embedded permanent magnet synchronous motor as described in any one of the above is implemented.

[0015] In a fourth aspect of the present invention, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the voltage limiting method of the embedded permanent magnet synchronous motor as described in any one of the above is implemented.

[0016] In summary, one or more technical solutions provided in the present invention have at least the following technical effects or advantages: By limiting only the Q-axis voltage and keeping the D-axis voltage unchanged, the current oscillation problem that may be caused by adjusting the D-axis and Q-axis voltages simultaneously in the traditional method is effectively avoided. Specifically, the method first obtains the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor, and then limits the Q-axis voltage based on the D-axis voltage. The above-mentioned limiting strategy ensures that the square root of the D-axis voltage and the limited Q-axis voltage is less than the bus voltage, thereby effectively preventing the system from overvoltage. At the same time, since the D-axis voltage remains unchanged, interference with the D-axis current is avoided, which is conducive to maintaining the effect of weak magnetic control, especially under high-speed operation. Finally, the motor torque is adjusted based on the D-axis voltage and the limited Q-axis voltage, which not only ensures the safety of the output voltage, but also improves the stability of the system.

[0017] Through the above technical solution, not only the stability problem caused by the synchronous change of current in the traditional limiting technology is solved, but also while ensuring the voltage limiting effect, unnecessary interference to the motor control system is avoided, thereby improving the performance and stability of the embedded permanent magnet synchronous motor during high-speed operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a flow chart of a voltage limiting method for an embedded permanent magnet synchronous motor provided by an embodiment of the present invention.

[0020] Figure 2 It is a logic schematic diagram of a voltage limiting method for an embedded permanent magnet synchronous motor provided in an embodiment of the present invention.

[0021] Figure 3 It is a structural schematic diagram of a voltage limiting device for an embedded permanent magnet synchronous motor provided by an embodiment of the present invention.

[0022] Figure 4 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the existing embedded permanent magnet synchronous motor control technology, the voltage limiting strategy is a key link to ensure the safe and stable operation of the system. The traditional voltage limiting method is mainly based on the square sum of the D-axis and Q-axis voltages, and limits the total output voltage by scaling the two-axis voltages simultaneously. Although this method is simple and direct, there are some potential problems in practical applications.

[0025] Specifically, the traditional voltage limiting strategy first calculates the total output voltage Us of the system, and the calculation formula is: ; Among them, U d and U q The system then compares this total voltage Us with the DC bus voltage U dc For comparison. s Exceed U dc , it is necessary to scale the D-axis and Q-axis voltages in the same proportion to ensure that the output voltage does not exceed the bus voltage.d1 and U q1 ) is calculated as follows: ; ; The above method ensures that the scaled D-axis and Q-axis voltages meet the following conditions: ; This ensures that the total output voltage of the system will not exceed the DC bus voltage U dc This traditional limiting method can effectively prevent system overvoltage in practical applications, but it also brings some problems. The main problem is that this method will change the voltage of the D axis and Q axis at the same time, which means that the D axis current I d and Q axis current I q will change at the same time. In IPMSM control, I d It is mainly used to adjust the magnetic field strength of the motor, especially to achieve weak magnetic control at high speed; q It is mainly used to control the output torque of the motor. When these two currents change at the same time, it may cause the magnetic field strength and output torque of the motor to fluctuate at the same time.

[0026] This simultaneous fluctuation may cause system instability in some cases. Especially in the high-speed operation stage, due to the large back electromotive force of the motor, the system requires more precise control of the current. If the D-axis and Q-axis currents change drastically at the same time in this case, it may make it difficult for the system to quickly restore balance, and may even cause current out of control.

[0027] In addition, in the field weakening control area, precise control of the D-axis current is essential to maintain the motor's high-speed operation capability. Traditional limiting methods may interfere with the effect of field weakening control and affect the motor's performance in the high-speed area. At the same time, sudden changes in the Q-axis current may cause fluctuations in the motor torque, affecting the driving experience and the stability of the system.

[0028] In summary, although the traditional voltage limiting method can effectively prevent system overvoltage, it may cause a series of problems in practical applications, especially in high-speed operation and weak magnetic control areas. These problems may affect the control accuracy of the motor, the stability of the system, and the overall performance. Therefore, in actual electric vehicle applications, more advanced and sophisticated voltage limiting strategies need to be considered to balance the safety, stability, and performance requirements of the system.

[0029] Based on the above defects of the prior art, please refer to Figure 1 , Figure 1The present invention provides a flow chart of a method for voltage limiting of an embedded permanent magnet synchronous motor provided by an embodiment of the present invention. The method can be implemented by a computer program, can be implemented by a single-chip microcomputer, or can be run on a voltage limiting system of an embedded permanent magnet synchronous motor based on a von Neumann system. The computer program can be integrated into an application or run as an independent tool application. Specifically, the method can include the following steps: S101. Obtain a D-axis voltage and a Q-axis voltage of an embedded permanent magnet synchronous motor.

[0030] Specifically, in the control system of the embedded permanent magnet synchronous motor, the D-axis voltage and the Q-axis voltage are two key parameters, which correspond to two important aspects of motor control. The D-axis voltage refers to the voltage applied to the direct axis of the motor, which is mainly used to control the magnetic field strength of the motor; the Q-axis voltage refers to the voltage applied to the quadrature axis, which is mainly used to control the torque output of the motor.

[0031] Among them, the D-axis voltage can be understood as the voltage value output by the D-axis current regulator, which reflects the system's control requirements for the motor's magnetic field strength. Especially when running at high speed, the D-axis voltage is often used to achieve weak magnetic control, that is, to offset the excessive back electromotive force generated by high-speed rotation by increasing the negative D-axis current. The Q-axis voltage can be understood as the voltage value output by the Q-axis current regulator, which is directly related to the motor's torque output and reflects the system's control requirements for the motor's output power.

[0032] Furthermore, the D-axis voltage is mainly used to adjust the magnetic field strength of the motor, which is especially important when running at high speeds. It can expand the speed range of the motor through weak magnetic control. By properly controlling the D-axis voltage, the back electromotive force can be reduced at high speeds to avoid system voltage saturation, thereby ensuring that the motor can operate stably within a wider speed range. The Q-axis voltage is mainly used to control the torque output of the motor, which directly affects the acceleration performance and load capacity of the motor. By adjusting the Q-axis voltage, the system can accurately control the output torque of the motor to meet the power requirements under different working conditions.

[0033] Based on the above embodiment, as an optional embodiment, in S101: the step of obtaining the D-axis voltage and the Q-axis voltage of the embedded permanent magnet synchronous motor may further include the following steps: S201: Obtain the three-phase current and rotor position of the embedded permanent magnet synchronous motor.

[0034] Specifically, the three-phase current includes the current values ​​of phase A, phase B and phase C, which reflect the current operating status of the motor; and the rotor position information is used to determine the spatial direction of the motor's magnetic field and is a key parameter for achieving vector control.

[0035] Current sensors, such as Hall current sensors or shunt resistors, are usually used to obtain three-phase currents, which are installed at the three-phase input terminals of the motor. These sensors can measure the current value flowing through each phase winding in real time, and convert the analog signal into a digital signal and output it to the controller. The rotor position can be obtained through position sensors such as rotary encoders, Hall sensors or resolvers. For high-performance control systems, high-precision rotary encoders are often used, which can provide accurate rotor angle information. In actual operation, the controller can collect the output signal of the current sensor through an analog-to-digital converter and read the data of the position sensor through a dedicated interface.

[0036] S202: Determine a D-axis current and a Q-axis current of the embedded permanent magnet synchronous motor based on the three-phase current and the rotor position.

[0037] Specifically, the controller first needs to convert the three-phase current into a two-phase stationary coordinate system (α-β coordinate system) through Clarke transformation, and then convert the current in the α-β coordinate system into a rotating DQ coordinate system through Park transformation. a , I b , I c ) is converted into two-phase orthogonal current (I α , I β ), where Iα is in the same direction as A, I β with I α Orthogonal. Park transformation uses the rotor position information θ to transform I α and I β Projecting onto the D and Q axes that rotate synchronously with the rotor, we get I d and I q .

[0038] S203: Convert the D-axis current into the D-axis voltage, and convert the Q-axis current into the Q-axis voltage.

[0039] Specifically, a proportional-integral (PI) controller can be used. For the D-axis and Q-axis, separate PI controllers are used. The input of the PI controller is the current error, that is, the difference between the actual current and the reference current, and the output is the corresponding voltage. This conversion takes into account the dynamic characteristics of the motor and can respond quickly to changes in current, thereby achieving precise control of the motor.

[0040] S102 . Limit the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage, wherein a square root of the D-axis voltage and the limited Q-axis voltage is less than a bus voltage of the embedded permanent magnet synchronous motor.

[0041] Based on the above examples, please refer to Figure 2 , Figure 2A logic schematic diagram of a voltage limiting method for an embedded permanent magnet synchronous motor provided in an embodiment of the present invention.

[0042] After obtaining the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor, the Q-axis voltage needs to be limited to ensure that the total output voltage of the motor does not exceed the bus voltage while keeping the D-axis voltage basically unchanged. The purpose of this limiting strategy is to avoid the current oscillation problem that may be caused by modifying the D-axis and Q-axis voltages at the same time in the traditional method, especially when the motor is running at high speed.

[0043] Furthermore, it ensures that the total output voltage of the system will not exceed the bus voltage, avoiding current runaway due to overvoltage. Secondly, since only the Q-axis voltage is limited without changing the D-axis voltage, this method effectively maintains the effect of weak magnetic control, which is particularly suitable for the high-speed operation stage of the motor. Finally, by avoiding adjusting the D-axis and Q-axis voltages at the same time, this method greatly reduces the risk of current oscillation in the system and improves the stability and reliability of the entire motor control system.

[0044] Based on the above embodiment, as an optional embodiment, in S102: the step of performing voltage limiting on the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage may further include the following steps: S301. Determine a first amplitude limiting range of a D-axis voltage based on a bus voltage of an embedded permanent magnet synchronous motor.

[0045] The first limit range refers to the allowable variation range of the D-axis voltage of the embedded permanent magnet synchronous motor. In the embodiment of the present invention, it can be understood as the upper and lower limits of the D-axis voltage determined based on the bus voltage Udc, that is, [-U dc ,U dc Specifically, the upper limit of the D-axis voltage U dlimtH Set to U dc , the lower limit U dlimtL Set to -U dc , forming a symmetrical voltage range.

[0046] Furthermore, the first limiting range is used to ensure that the D-axis voltage always remains within a safe and effective range. It can be used to prevent system overvoltage. By limiting the D-axis voltage to a range not exceeding the bus voltage, problems such as system instability or current out of control caused by excessive voltage can be effectively avoided. Secondly, it provides sufficient adjustment space for weak magnetic control. Especially when the motor is running at high speed, it is necessary to adjust the D-axis voltage to achieve a weak magnetic effect and reduce the back electromotive force. This limiting range ensures that the D-axis voltage has enough room to change to achieve this goal. Furthermore, it provides an important basis for the subsequent Q-axis voltage limiting calculation. When determining the Q-axis voltage limiting value, the actual value of the D-axis voltage needs to be considered, and this first limiting range of the D-axis voltage provides a clear calculation basis for the Q-axis voltage limiting. Finally, it is used to monitor and adjust the D-axis voltage in real time. In each control cycle, the system will calculate the actual D-axis voltage U d Compared with this limit range, if U d If it exceeds the range, it will be limited immediately. d Limit it to this safe range.

[0047] S302 . Perform voltage limiting on the Q-axis voltage based on the D-axis voltage within a first limiting range.

[0048] Specifically, after determining the first limiting range of the D-axis voltage, the Q-axis voltage needs to be limited based on the D-axis voltage within the first limiting range, thereby ensuring that the total output voltage of the motor does not exceed the bus voltage while maintaining the stability of the D-axis voltage.

[0049] Based on the above embodiment, as an optional embodiment, in S302: within the first limiting range, the step of performing voltage limiting on the Q-axis voltage based on the D-axis voltage may further specifically include the following steps: S401 , determining whether the D-axis voltage exceeds a first limiting range.

[0050] S402 : If the D-axis voltage exceeds the first limiting range, the D-axis voltage is set to a boundary value of the first limiting range, and the Q-axis voltage is set to 0.

[0051] Specifically, in the voltage limiting process of the embedded permanent magnet synchronous motor, processing the D-axis voltage is a crucial step. This embodiment further improves the voltage limiting method and improves the safety and stability of the system by judging whether the D-axis voltage exceeds the first limiting range and taking corresponding measures when it exceeds the first limiting range.

[0052] Specifically, we first need to determine the D-axis voltage U d Whether it exceeds the first limit range defined previously [-U dc ,U dc]. This judgment process can be achieved by comparing U d With upper limit U dlimtH and the lower limit U dlimtL To achieve this. If U d Greater than U dlimtH or less than U dlimtL , it is considered that the D-axis voltage exceeds the first limiting range.

[0053] When the D-axis voltage exceeds the first limiting range, the method adopts a special processing strategy: the D-axis voltage is set to the boundary value of the first limiting range, and the Q-axis voltage is set to 0. Specifically, if U d Greater than U dlimtH , then set Ud to U dlimtH ; If U d Less than U dlimtL , then U d Set to U dlimtL In either case, the Q-axis voltage U q are all set to 0.

[0054] The principle of the above processing method is based on the following considerations: When the D-axis voltage reaches or exceeds the bus voltage, the system is already in a limit state. At this time, continuing to increase the Q-axis voltage may cause the total output voltage to exceed the bus voltage, causing an overvoltage problem. By setting the Q-axis voltage to 0, it can be ensured that the total output voltage of the system will not exceed the bus voltage, thereby avoiding possible current runaway and system instability.

[0055] At the same time, it is also very important to keep the D-axis voltage within the limit range. The D-axis voltage is mainly used to control the magnetic field strength of the motor, especially for realizing weak magnetic control at high speed operation. By limiting the D-axis voltage to [-U dc ,U dc ] range, the effectiveness of weak magnetic control can be ensured while avoiding system instability caused by excessive D-axis voltage.

[0056] Based on the above embodiment, as another optional embodiment, in S302: within the first limiting range, the step of performing voltage limiting on the Q-axis voltage based on the D-axis voltage may further specifically include the following steps: S501: If it is determined that the D-axis voltage is within the first amplitude limiting range, the square root of the square difference between the D-axis voltage and the output voltage is used as the second amplitude limiting range of the Q-axis voltage.

[0057] S502: Limit the Q-axis voltage based on the second limiting range.

[0058] The second limiting range refers to the allowable variation range of the Q-axis voltage under the premise of ensuring the stability of the D-axis voltage. In the embodiment of the present invention, it can be understood as the upper and lower limits of the Q-axis voltage calculated based on the square root of the square difference between the D-axis voltage and the output voltage: Specifically, the upper limit of the Q-axis voltage is ; Lower limit , forming a symmetrical voltage range centered on 0. The second limiting range is used to maximize the available range of the Q-axis voltage while ensuring that the total output voltage of the system does not exceed the bus voltage.

[0059] Furthermore, the second limiting range can also be used to ensure that the total output voltage of the system does not exceed the bus voltage at all times. By limiting the Q-axis voltage to this dynamically calculated range, problems such as system instability or current out of control caused by excessive voltage can be effectively prevented; secondly, it is used to optimize the allocation of voltage resources. Under the premise of ensuring the stability of the D-axis voltage, this range maximizes the available range of the Q-axis voltage, thereby improving the dynamic performance and efficiency of the system; thirdly, it provides a clear boundary for the real-time adjustment of the Q-axis voltage. In each control cycle, the system recalculates this range based on the current D-axis voltage, and limits the Q-axis voltage accordingly, thereby achieving dynamic optimization of voltage control.

[0060] Based on the above embodiment, as an optional embodiment, S502 may further include the following steps: S601: Determine whether the Q-axis voltage exceeds a second limiting range.

[0061] S602: If the Q-axis voltage exceeds the second limiting range, set the Q-axis voltage to the boundary value of the first limiting range.

[0062] Specifically, when the Q-axis voltage exceeds the second limiting range, the method adopts a special processing strategy: setting the Q-axis voltage to the boundary value of the second limiting range. q Greater than U qlimtH , then U q Set to U qlimtH ; If U q Less than U qlimtL , then U q Set to U qlimtL This processing method ensures that the Q-axis voltage always remains within the maximum allowable range.

[0063] The principle of this processing method is based on the following considerations: The second limiting range is dynamically calculated based on the current D-axis voltage, which represents the maximum available range of the Q-axis voltage under the premise of ensuring that the total system output voltage does not exceed the bus voltage. By limiting the Q-axis voltage that exceeds the range to the boundary value, we can maximize the use of available voltage resources while ensuring that the system will not be out of control due to overvoltage.

[0064] In addition, this method also maintains the stability of the D-axis voltage. Since the D-axis voltage is mainly used to control the magnetic field strength of the motor, especially for achieving weak magnetic control at high speeds, keeping it stable is crucial to the overall performance of the motor. By adjusting only the Q-axis voltage without changing the D-axis voltage, this method ensures the effectiveness of weak magnetic control while optimizing torque control.

[0065] Furthermore, it provides a reliable protection mechanism to prevent the system from overvoltage problems caused by excessive Q-axis voltage. Secondly, by limiting the Q-axis voltage to the maximum range of dynamic calculation, this method achieves optimal utilization of voltage resources and improves the dynamic performance and efficiency of the system. Furthermore, this method maintains the stability of the D-axis voltage and the effect of weak magnetic control, which is particularly suitable for the high-speed operation stage of the motor. Finally, by timely adjusting the Q-axis voltage, this method effectively reduces the risk of current oscillation and improves the overall stability of the system.

[0066] In practical applications, the above processing method can be integrated into the voltage modulation module of the motor control system. In each control cycle, the system checks whether the Q-axis voltage exceeds the limit range and performs the above adjustment if necessary. This real-time and dynamic processing strategy enables the system to maintain optimal performance in various operating conditions, especially in the case of high dynamic requirements.

[0067] S103 , adjusting the torque of the embedded permanent magnet synchronous motor based on the D-axis voltage and the limited Q-axis voltage.

[0068] Specifically, in a permanent magnet synchronous motor, the D-axis voltage is mainly used to control the magnetic field strength, especially for realizing magnetic field weakening control when running at high speed; while the Q-axis voltage is mainly used to control the torque output. Therefore, by reasonably adjusting these two voltage components, the torque output of the motor can be accurately controlled.

[0069] Please refer to Figure 3 , Figure 3 A schematic structural diagram of a voltage limiting device for an embedded permanent magnet synchronous motor provided by an embodiment of the present invention, wherein the device may include: A voltage acquisition module is used to obtain the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; a voltage limiting module, configured to perform voltage limiting on the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage, wherein a square root of the D-axis voltage and the limited Q-axis voltage is less than a bus voltage of the embedded permanent magnet synchronous motor; A voltage regulation module is used to regulate the torque of the embedded permanent magnet synchronous motor based on the D-axis voltage and the limited Q-axis voltage.

[0070] Based on the above embodiment, as an optional embodiment, the voltage acquisition module is also used to obtain the three-phase current and rotor position of the embedded permanent magnet synchronous motor; based on the three-phase current and the rotor position, determine the D-axis current and Q-axis current of the embedded permanent magnet synchronous motor; convert the D-axis current into a D-axis voltage, and convert the Q-axis current into a Q-axis voltage.

[0071] Based on the above embodiments, as an optional embodiment, the voltage limiting module is also used to determine the first limiting range of the D-axis voltage based on the bus voltage of the embedded permanent magnet synchronous motor; within the first limiting range, the Q-axis voltage is limited based on the D-axis voltage.

[0072] Based on the above embodiment, as an optional embodiment, the voltage limiting module is also used to determine whether the D-axis voltage exceeds the first limiting range; if the D-axis voltage exceeds the first limiting range, the D-axis voltage is set to the boundary value of the first limiting range, and the Q-axis voltage is set to 0.

[0073] Based on the above embodiment, as an optional embodiment, the voltage limiting module is also used to, if it is determined that the D-axis voltage is within the first limiting range, use the square root of the square difference between the D-axis voltage and the output voltage as the second limiting range of the Q-axis voltage; and limit the Q-axis voltage based on the second limiting range.

[0074] Based on the above embodiment, as an optional embodiment, the voltage limiting module is also used to determine whether the Q-axis voltage exceeds the second limiting range; if the Q-axis voltage exceeds the second limiting range, the Q-axis voltage is set to the boundary value of the first limiting range.

[0075] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430 and a communication bus 440, wherein the processor 410, the communication interface 420 and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute the voltage limiting method of the embedded permanent magnet synchronous motor.

[0076] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0077] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the voltage limiting method of the embedded permanent magnet synchronous motor provided by the above-mentioned methods.

[0078] On the other hand, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the voltage limiting method of the embedded permanent magnet synchronous motor provided by the above methods.

[0079] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage limiting method for an embedded permanent magnet synchronous motor, characterized in that: include: Obtain the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; Based on the D-axis voltage, the Q-axis voltage is voltage-limited to obtain the Q-axis voltage after the voltage limiting, wherein the square root of the D-axis voltage and the Q-axis voltage after the voltage limiting is less than the bus voltage of the embedded permanent magnet synchronous motor; The torque of the embedded permanent magnet synchronous motor is adjusted based on the D-axis voltage and the limited Q-axis voltage.

2. The voltage limiting method of the embedded permanent magnet synchronous motor according to claim 1, characterized in that: The obtaining of the D-axis voltage and the Q-axis voltage of the embedded permanent magnet synchronous motor includes: Obtain the three-phase current and rotor position of the embedded permanent magnet synchronous motor; Determining a D-axis current and a Q-axis current of the embedded permanent magnet synchronous motor based on the three-phase current and the rotor position; The D-axis current is converted into a D-axis voltage, and the Q-axis current is converted into a Q-axis voltage.

3. The voltage limiting method of the embedded permanent magnet synchronous motor according to claim 1, characterized in that: The voltage limiting of the Q-axis voltage based on the D-axis voltage is characterized by comprising: Determining a first amplitude limiting range of the D-axis voltage based on a bus voltage of the embedded permanent magnet synchronous motor; In the first limiting range, the Q-axis voltage is limited based on the D-axis voltage.

4. The voltage limiting method of the embedded permanent magnet synchronous motor according to claim 3, characterized in that: The step of limiting the Q-axis voltage based on the D-axis voltage within the first limiting range includes: Determining whether the D-axis voltage exceeds the first limiting range; If the D-axis voltage exceeds the first limiting range, the D-axis voltage is set to a boundary value of the first limiting range, and the Q-axis voltage is set to 0.

5. The voltage limiting method of the embedded permanent magnet synchronous motor according to claim 3, characterized in that: The step of limiting the Q-axis voltage based on the D-axis voltage within the first limiting range includes: If it is determined that the D-axis voltage is within the first amplitude limiting range, a square root of a square difference between the D-axis voltage and the output voltage is used as a second amplitude limiting range of the Q-axis voltage; The Q-axis voltage is limited based on the second limiting range.

6. The voltage limiting method of the embedded permanent magnet synchronous motor according to claim 5, characterized in that: The limiting the Q-axis voltage based on the second limiting range includes: Determining whether the Q-axis voltage exceeds the second limiting range; If the Q-axis voltage exceeds the second amplitude limiting range, the Q-axis voltage is set to a boundary value of the first amplitude limiting range.

7. A voltage limiting device for an embedded permanent magnet synchronous motor, characterized in that: include: A voltage acquisition module is used to obtain the D-axis voltage and Q-axis voltage of the embedded permanent magnet synchronous motor; a voltage limiting module, configured to perform voltage limiting on the Q-axis voltage based on the D-axis voltage to obtain the limited Q-axis voltage, wherein a square root of the D-axis voltage and the limited Q-axis voltage is less than a bus voltage of the embedded permanent magnet synchronous motor; A voltage regulation module is used to regulate the torque of the embedded permanent magnet synchronous motor based on the D-axis voltage and the limited Q-axis voltage.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the voltage limiting method of the embedded permanent magnet synchronous motor as claimed in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the voltage limiting method of the embedded permanent magnet synchronous motor as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the voltage limiting method of the embedded permanent magnet synchronous motor as claimed in any one of claims 1 to 6 is implemented.

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