Permanent magnet synchronous motor three-phase short-circuit transient modeling method and device

Abstract

This invention discloses a method and apparatus for three-phase short-circuit transient modeling of a permanent magnet synchronous motor. The method includes: acquiring the parameter values ​​of the motor body, the initial values ​​of the synchronous motor during a short circuit, and the constraints; determining the dq-axis current value based on the motor body parameters, the initial values ​​during the short circuit, and the constraints; and establishing a three-phase short-circuit transient model based on the dq-axis current value. This invention establishes motor equations and electromagnetic torque equations based on the motor body parameters, and derives an analytical transient model of active short circuit by determining the initial conditions during a short circuit. This allows for the acquisition of the dq-axis current and torque at any given time, providing a precise data foundation for realizing active short circuits. Furthermore, the analytical model helps the controller set reasonable compensation and achieve precise adjustment.

Description

Technical Field

[0001] This disclosure relates to the field of permanent magnet synchronous motor model building technology, and more specifically, to a method and apparatus for three-phase short-circuit transient modeling of a permanent magnet synchronous motor. Background Technology

[0002] Currently, the environment and energy have become increasingly important issues. In the automotive sector, efficient, energy-saving, and environmentally friendly new energy vehicles have become an inevitable development trend. Permanent magnet synchronous motor drive systems can achieve low energy consumption and zero emissions, making them highly promising for the market.

[0003] In the control of permanent magnet synchronous motors, especially automotive permanent magnet synchronous motors, unpredictable faults and harsh operating conditions are often encountered. When the fault level reaches a certain level (overcurrent, overvoltage, stall, etc.), it is necessary to adopt a method to quickly discharge the motor energy to achieve a rapid stop.

[0004] Currently, there are generally two ways to implement active short circuit. One is through hardware design, which involves designing an active short circuit circuit. The other is through software design, which involves monitoring the motor's operating status and determining whether the motor needs to enter a safe state. When a safe state is required, the back EMF line voltage at the current and next moment is calculated based on the rotor position of the motor controller. Based on the motor entering a safe state and the motor threshold, an enable signal for the motor controller is generated. The motor's dq-axis current is controlled as a characteristic current, and a control action signal is output, enabling the drive signal to safely control the inverter to turn on the corresponding switches.

[0005] However, by detecting current, voltage, and motor speed and comparing them with a set threshold, the three-phase bridge inverter is controlled to enter short-circuit mode after the threshold is reached. However, there is no mathematical analysis and description of the transient process of active short circuit, and the dq axis current and torque at any time cannot be known, which can easily cause the motor current and torque to run away from control. Summary of the Invention

[0006] In view of this, the purpose of this disclosure is to provide a three-phase short-circuit transient modeling method and device for permanent magnet synchronous motors, so as to solve the technical problem in the prior art that the dq axis current and torque cannot be predicted at any time, which easily leads to current and torque runaway.

[0007] To achieve the above objectives, in a first aspect, this disclosure provides a three-phase short-circuit transient modeling method for a permanent magnet synchronous motor, comprising: acquiring parameter values ​​of the motor body, initial values ​​of the motor under short circuit, and constraint conditions; determining the dq-axis current value of the permanent magnet synchronous motor based on the parameter values, the initial values, and the constraint conditions; and establishing a three-phase short-circuit transient model based on the dq-axis current value to obtain the dq-axis current and torque.

[0008] In some embodiments, the motor body parameters include resistance, direct-axis inductance, quadrature-axis inductance, permanent magnet flux linkage, and number of pole pairs.

[0009] In some embodiments, the initial values ​​include the initial torque, the initial speed, the initial current amplitude, and the dq-axis component of the initial current.

[0010] In some embodiments, determining the dq-axis current value based on the motor body parameters and the initial value during short circuit includes: determining the electromagnetic torque based on the motor body parameters; and determining the dq-axis current value based on the electromagnetic torque and the initial current value.

[0011] In some embodiments, establishing a three-phase short-circuit transient model based on the dq-axis current value includes: obtaining a dq-axis current sub-model based on the dq-axis current value; and determining a braking torque sub-model based on the dq-axis current model.

[0012] In some embodiments, the dq-axis current sub-model includes: a first current sub-model, wherein the first current sub-model is the change of the dq-axis current over time when the initial current value is 0; and a second current sub-model, wherein the second current sub-model is the change of the dq-axis current over time when the initial current value is not 0.

[0013] In some embodiments, obtaining the dq-axis current sub-model based on the dq-axis current value includes: determining a first current sub-model based on the dq-axis current value when the initial current value is 0; and determining a second current sub-model based on the dq-axis current value when the initial current value is not 0.

[0014] Secondly, this disclosure also provides a three-phase short-circuit transient modeling device for a permanent magnet synchronous motor, comprising:

[0015] The acquisition module is used to acquire the parameter values ​​of the motor body, the initial values ​​of the motor under short circuit, and the constraint conditions; the determination module is used to determine the dq axis current value based on the motor body parameters, the initial values ​​under short circuit, and the constraint conditions; the model building module is used to build a three-phase short-circuit transient model based on the dq axis current value.

[0016] Thirdly, this disclosure also provides a storage medium storing a computer program, which, when executed by a processor, implements the steps of the method described in any of the above technical solutions.

[0017] Fourthly, this disclosure also provides an electronic device, including at least a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program in the memory, implements the steps of the method described in any of the above technical solutions.

[0018] This embodiment establishes motor equations and electromagnetic torque equations based on the motor body parameters. By determining the initial conditions during a short circuit, a transient analytical model for active short circuit is derived, thereby obtaining the dq-axis current and torque at any time. This provides a precise data foundation for realizing active short circuit. At the same time, the analytical model can help the controller set reasonable compensation and achieve precise adjustment.

[0019] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the steps of the three-phase short-circuit transient modeling method for permanent magnet synchronous motors provided in this disclosure;

[0022] Figure 2 This is a schematic diagram illustrating the steps for obtaining the dq-axis current value in the modeling method provided in this disclosure;

[0023] Figure 3 This is a schematic diagram illustrating the steps involved in determining the three-phase short-circuit transient model using the modeling method provided in this disclosure;

[0024] Figure 4 This is a structural block diagram of the three-phase short-circuit transient modeling device for permanent magnet synchronous motors provided in this disclosure;

[0025] Figure 5 This is a schematic diagram of the structure of the electronic device provided in this disclosure. Detailed Implementation

[0026] The specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, but these are not intended to limit the scope of this disclosure.

[0027] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this disclosure will be apparent to those skilled in the art.

[0028] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present disclosure and, together with the general description of the disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

[0029] These and other features of this disclosure will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0030] It should also be understood that although this disclosure has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this disclosure, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0031] The above and other aspects, features and advantages of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0032] Specific embodiments of the present disclosure are described thereafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the present disclosure. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely to serve as the basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of substantially any suitable detailed structures.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in still another embodiment,” all of which may refer to one or more of the same or different embodiments according to this disclosure.

[0035] The present disclosure will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] The first embodiment of this disclosure relates to the field of permanent magnet synchronous motors, specifically to a three-phase short-circuit transient modeling method for permanent magnet synchronous motors. The permanent magnet synchronous motor here includes an axial flux permanent magnet synchronous motor (AFPMSM), where the flux direction is axial. It has advantages such as simple structure, small size, flexible control, and high efficiency. This motor typically employs a rotor field-oriented vector control method and is suitable for pure electric vehicles.

[0038] like Figure 1 As shown, the three-phase short-circuit transient modeling method for permanent magnet synchronous motors includes the following steps:

[0039] S101, obtain the parameter values ​​of the motor body, the initial values ​​of the motor when it is short-circuited, and the constraint conditions.

[0040] In this step, the parameter values ​​of the motor body, the initial values ​​of the motor under short circuit, and the constraint conditions are obtained; wherein, the parameter values ​​of the motor body include resistance, direct-axis inductance, quadrature-axis inductance, permanent magnet flux linkage, and number of pole pairs, and the initial values ​​include starting torque, starting speed, starting current amplitude, and dq-axis component of starting current.

[0041] Using classical transformation and based on the principle of constant amplitude transformation, the voltage of the permanent magnet synchronous motor can be obtained as follows.

[0042]

[0043] When a three-phase event occurs in a permanent magnet synchronous motor, the following constraints must be met:

[0044]

[0045] Where R is the stator phase resistance, p n For the extreme logarithm, u d u q L represents the dq-axis voltage component of the permanent magnet motor. d L q For the dq axis inductance of the permanent magnet motor, i d i q Ω represents the stator armature current component of the dq axis of the permanent magnet motor, Ω represents the mechanical angular velocity, and Ψ represents the mechanical angular velocity. f Te represents the permanent magnet flux linkage and Te represents the electromagnetic torque.

[0046] S102, based on the motor body parameters, the initial value during the short circuit, and the constraint conditions, obtain the dq axis current value.

[0047] After completing step S101 above, in this step, the dq-axis current value is obtained based on the motor body parameter values, the initial value during short circuit, and the constraint conditions. For example... Figure 2As shown, the specific steps for obtaining the dq-axis current value are as follows:

[0048] S201, determine the electromagnetic torque based on the motor body parameters.

[0049] In this step, the electromagnetic torque is determined based on the motor's body parameters. According to the torque equation of a permanent magnet synchronous motor:

[0050]

[0051] Based on equations (1) and (2), we can obtain:

[0052]

[0053] S202, determine the dq axis current value based on the electromagnetic torque and the initial current value.

[0054] After completing step S201 above, in this step, the dq-axis current value is determined based on the electromagnetic torque and the initial current value.

[0055] When the initial current is zero, performing a Laplace transform on equation (4) yields the following equation (5):

[0056]

[0057] Converting equation (5) into matrix form, we obtain equation (6):

[0058]

[0059] By using a second-order inverse matrix to solve formula (6), the dq-axis current value when the initial current value is zero is obtained:

[0060]

[0061] in,

[0062]

[0063]

[0064] When the initial current value is not zero, performing a Laplace transform on equation (4) yields equation (9):

[0065]

[0066] Converting equation (9) into matrix form, we obtain equation (10):

[0067]

[0068] By using a second-order inverse matrix to calculate and solve formula (10), the dq-axis current value when the initial current value is not zero is obtained:

[0069]

[0070] S103, a three-phase short-circuit transient model is established based on the dq axis current values.

[0071] After determining the dq-axis current value, this step determines the three-phase short-circuit transient model based on the dq-axis current value. For example... Figure 3 As shown, the specific steps include:

[0072] S301, Obtain the dq-axis current sub-model based on the dq-axis current value.

[0073] First, a dq-axis current sub-model is obtained based on the dq-axis current value, wherein the dq-axis current sub-model includes a first current sub-model and a second current sub-model.

[0074] Specifically, the first current sub-model is the change of the dq-axis current over time when the initial current value is zero; the second current sub-model is the change of the dq-axis current over time when the initial current value is not zero.

[0075] When the initial current is zero, under high-speed conditions, the square root of equation (8) is negative, thus generating conjugate complex roots. Assume the real and imaginary parts of the conjugate complex roots are respectively... and Then we have:

[0076] (s-s1)(s-s2)=[s-(σ+jv)]·[s-(σ-jυ)]=(s-σ) 2 +v 2 Equation (12)

[0077] Therefore, we can perform the following partial fractional expansion on equation (7):

[0078]

[0079] From equations (7) and (13), we can obtain the following equation:

[0080]

[0081] Solving the above equation, we obtain the analytical values ​​of coefficients A, B, C, X, Y, and Z:

[0082]

[0083] Using the commonly used Laplace transform relation (15):

[0084]

[0085] Performing an inverse Laplace transform on equations (13) and (14), we can obtain the first current sub-model, that is, the expression for the dq-axis current when the initial current value is zero after a three-phase short circuit:

[0086]

[0087] When the initial value of the current is not zero, the following partial expansion is made to equation (11):

[0088]

[0089] From equations (11) and (17), the analytical values ​​of coefficients A, B, C, X, Y, and Z are obtained as follows:

[0090]

[0091] From the Laplace transform formula (15), the inverse Laplace transform is performed to obtain the second current sub-model, that is, the expression for the dq axis current when the initial current value is not zero after a three-phase short circuit:

[0092]

[0093] S302, determine the braking torque sub-model based on the dq axis current sub-model.

[0094] After obtaining the dq-axis current sub-model, the braking torque sub-model is determined based on the dq-axis current sub-model. Using formulas (16) and (19), the braking torque at any moment during the short circuit can be calculated using formula (3):

[0095]

[0096] Equations (16), (19), and (20) together constitute the three-phase short-circuit transient model of the permanent magnet synchronous motor.

[0097]

[0098] By establishing a three-phase short-circuit transient model of a permanent magnet synchronous motor (PMSM), it can be seen that during a three-phase short circuit, the short circuit is symmetrical. The response characteristics of the shaft current are independent of the rotor position, but depend on the motor's intrinsic parameters (resistance, inductance, flux linkage, number of pole pairs) and the operating state (speed, torque / current) at the moment of the short circuit. However, since the shaft current is obtained by coordinate transformation of the three-phase currents, and the electrical angle position of the motor is involved in the coordinate transformation process, the current distribution on each phase winding is related to the rotor position at the moment of the short circuit. Simultaneously, it can be observed that the shaft current response consists of steady-state and transient components. The steady-state component mainly depends on the motor's intrinsic parameters and speed, while the transient component gradually converges.

[0099] According to the three-phase short-circuit transient modeling method for permanent magnet synchronous motors provided in this disclosure, motor equations and electromagnetic torque equations are established based on the motor body parameters. By determining the initial conditions during a short circuit, a transient analytical model for active short circuit is derived, thereby obtaining the dq-axis current and torque at any time. This provides an accurate data basis for realizing active short circuit. At the same time, the analytical model can help the controller set reasonable compensation and achieve precise adjustment.

[0100] Example 2

[0101] To better implement the above methods, a second aspect of this disclosure also provides a three-phase short-circuit transient modeling device for a permanent magnet synchronous motor, which can be integrated into an electronic device.

[0102] For example, such as Figure 4 As shown, the modeling device 200 may include: an acquisition module 210, a determination module 220, and a model building module 230, as detailed below:

[0103] (1) Acquisition module 210 is used to acquire the parameter values ​​of the motor body, the initial value of the synchronous motor when it is short-circuited, and the constraint conditions.

[0104] Specifically, the acquisition module 210 is used to acquire the parameter values ​​of the motor body, the initial values ​​of the synchronous motor when it is short-circuited, and the constraint conditions. The parameter values ​​of the motor body include resistance, direct-axis inductance, quadrature-axis inductance, permanent magnet flux linkage, and number of pole pairs. The initial values ​​include starting torque, starting speed, starting current amplitude, and dq-axis component of starting current.

[0105] (2) Determine module 220, which is used to determine the dq axis current value based on the motor body parameters, the initial value during short circuit and the constraint conditions.

[0106] (3) Model building module 230 is used to build a three-phase short-circuit transient model based on the dq axis current value to obtain the dq axis current and torque.

[0107] Specifically, the model building module 230 may further include a current sub-model building unit and a torque sub-model building unit. The current sub-model building unit obtains a dq-axis current sub-model based on the dq-axis current value; the torque sub-model building unit determines a braking torque sub-model based on the dq-axis current model.

[0108] According to the three-phase short-circuit transient modeling method for permanent magnet synchronous motors provided in this disclosure, motor equations and electromagnetic torque equations are established based on the motor body parameters. By determining the initial conditions during a short circuit, a transient analytical model for active short circuit is derived, thereby obtaining the dq-axis current and torque at any time. This provides an accurate data basis for realizing active short circuit. At the same time, the analytical model can help the controller set reasonable compensation and achieve precise adjustment.

[0109] Example 3

[0110] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0111] Therefore, a third embodiment of this disclosure provides a storage medium, which is a computer-readable medium storing a computer program. When executed by a processor, the computer program implements the method provided in the embodiments of this disclosure, including the following steps S11 to S13:

[0112] S11, obtain the parameter values ​​of the motor body, the initial values ​​of the synchronous motor when it is short-circuited, and the constraint conditions;

[0113] S12, Determine the dq axis current value based on the motor body parameters, the initial value during short circuit, and the constraint conditions;

[0114] S13, A three-phase short-circuit transient model is established based on the dq axis current values.

[0115] Furthermore, when the computer program is executed by a processor, it implements other methods provided in any of the above embodiments of this disclosure.

[0116] According to the three-phase short-circuit transient modeling method for permanent magnet synchronous motors provided in this disclosure, motor equations and electromagnetic torque equations are established based on the motor body parameters. By determining the initial conditions during a short circuit, a transient analytical model for active short circuit is derived, thereby obtaining the dq-axis current and torque at any time. This provides an accurate data basis for realizing active short circuit. At the same time, the analytical model can help the controller set reasonable compensation and achieve precise adjustment.

[0117] Example 4

[0118] The fourth embodiment of this disclosure provides an electronic device, such as... Figure 5 As shown, the electronic device includes at least a processor 401 and a memory 402. The memory 402 stores a computer program, and the processor 401 implements the methods provided in any embodiment of this disclosure when executing the computer program in the memory 402. For example, the method executed by the computer program in the electronic device is as follows:

[0119] S21, obtain the parameter values ​​of the motor body, the initial values ​​of the synchronous motor when it is short-circuited, and the constraint conditions;

[0120] S22, Based on the motor body parameters, the initial value during short circuit, and the constraint conditions, determine the dq axis current value;

[0121] S23, a three-phase short-circuit transient model is established based on the dq axis current values.

[0122] In practice, the acquisition module 210, the determination module 220 and the model building module 230 are all stored as program units in the memory 402, and the processor 401 executes the program units stored in the memory 402 to realize the corresponding functions.

[0123] According to the three-phase short-circuit transient modeling method for permanent magnet synchronous motors provided in this disclosure, motor equations and electromagnetic torque equations are established based on the motor body parameters. By determining the initial conditions during a short circuit, a transient analytical model for active short circuit is derived, thereby obtaining the dq-axis current and torque at any time. This provides an accurate data basis for realizing active short circuit. At the same time, the analytical model can help the controller set reasonable compensation and achieve precise adjustment.

[0124] The aforementioned storage medium may be included in the aforementioned electronic device; or it may exist independently and not be assembled into the electronic device.

[0125] The aforementioned storage medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to: acquire at least two Internet Protocol (IP) addresses; send a node evaluation request, including at least two IP addresses, to a node evaluation device, wherein the node evaluation device selects an IP address from the at least two IP addresses and returns it; and receive the IP address returned by the node evaluation device; wherein the acquired IP address indicates an edge node in the content delivery network.

[0126] Alternatively, the storage medium may carry one or more programs that, when executed by the electronic device, cause the electronic device to: receive a node evaluation request including at least two Internet Protocol (IP) addresses; select an IP address from the at least two IP addresses; and return the selected IP address; wherein the received IP address indicates an edge node in the content delivery network.

[0127] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the passenger's computer, partially on the passenger's computer, as a standalone software package, partially on the passenger's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the passenger's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0128] It should be noted that the storage medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any storage medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the storage medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0129] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0130] The units described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units are not, in some cases, intended to limit the specific unit.

[0131] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0132] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0133] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0134] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. In certain environments, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0135] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

[0136] The foregoing has provided a detailed description of several embodiments of this disclosure. However, this disclosure is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications based on the concept of this disclosure, and all such variations and modifications should fall within the scope of protection claimed by this disclosure.

Claims

1. A method for modeling the three-phase short-circuit transient state of a permanent magnet synchronous motor, characterized in that, include: The parameter values ​​of the motor body, the initial values ​​of the motor under short circuit, and the constraint conditions are obtained. The parameter values ​​of the motor body include resistance, direct-axis inductance, quadrature-axis inductance, permanent magnet flux linkage, and number of pole pairs. The initial values ​​include starting torque, starting speed, starting current amplitude, and dq-axis component of starting current. Based on the parameter values, the initial values, and the constraints, the dq axis current values ​​of the permanent magnet synchronous motor are determined. Determining the dq-axis current value based on the motor body parameters and the initial value during short circuit includes: determining the electromagnetic torque based on the motor body parameters; and determining the dq-axis current value based on the electromagnetic torque and the initial current value. A three-phase short-circuit transient model of the permanent magnet synchronous motor is established based on the dq axis current value to obtain the dq axis current and torque. Establishing a three-phase short-circuit transient model based on the dq-axis current value includes: obtaining a dq-axis current sub-model based on the dq-axis current value; and determining a braking torque sub-model based on the dq-axis current model. The dq-axis current sub-model includes: a first current sub-model, wherein the first current sub-model is the change of the dq-axis current over time when the initial current value is zero; and a second current sub-model, wherein the second current sub-model is the change of the dq-axis current over time when the initial current value is not zero. Obtaining the dq-axis current sub-model based on the dq-axis current value includes: determining a first current sub-model based on the dq-axis current value when the initial current value is zero; and determining a second current sub-model based on the dq-axis current value when the initial current value is not zero.

2. A three-phase short-circuit transient modeling device for a permanent magnet synchronous motor, characterized in that, include: The acquisition module is used to acquire the parameter values ​​of the motor body, the initial values ​​of the motor when it is short-circuited, and the constraint conditions. The parameter values ​​of the motor body include resistance, direct-axis inductance, quadrature-axis inductance, permanent magnet flux linkage, and number of pole pairs. The initial values ​​include starting torque, starting speed, starting current amplitude, and dq-axis component of starting current. The determination module is used to determine the dq axis current value of the permanent magnet synchronous motor based on the parameter value, the initial value, and the constraint conditions; The determining module is further configured to determine the electromagnetic torque based on the motor body parameters; and to determine the dq axis current value based on the electromagnetic torque and the initial current value. The model building module is used to build a three-phase short-circuit transient model based on the dq-axis current value to obtain the dq-axis current and torque. The model building module is also used to obtain a dq-axis current sub-model based on the dq-axis current value; and to determine a braking torque sub-model based on the dq-axis current model. The dq-axis current sub-model includes: a first current sub-model, wherein the first current sub-model is the change of the dq-axis current over time when the initial current value is zero; and a second current sub-model, wherein the second current sub-model is the change of the dq-axis current over time when the initial current value is not zero. The model building module is also used to determine a first current sub-model based on the dq-axis current value when the initial current value is zero, and to determine a second current sub-model based on the dq-axis current value when the initial current value is not zero.

3. A storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in claim 1.

4. An electronic device, comprising at least a memory and a processor, wherein the memory stores a computer program, characterized in that, The processor implements the steps of the method of claim 1 when executing a computer program on the memory.

Images