Fault-tolerant control method and device for high-resistance contact fault of five-phase permanent magnet synchronous motor

Abstract

The invention discloses a fault-tolerant control method and device for a high-resistance contact fault of a five-phase permanent magnet synchronous motor, and relates to the field of permanent magnet synchronous motors. The fault-tolerant control method comprises the following steps: acquiring an adjusting instruction for controlling a motor, wherein the adjusting instruction is used for indicating a target torque output by the motor; obtaining optimized reconstructed rotating orthogonal coordinate system current for the motor under different target torques; obtaining the voltage of the rotating orthogonal coordinate system according to the difference value between the current of the reconstructed rotating orthogonal coordinate system and the current of the actual rotating orthogonal coordinate system; obtaining a reconstructed rotating orthogonal coordinate system voltage according to the rotating orthogonal coordinate system voltage; and converting the voltage of the reconstructed rotating orthogonal coordinate system into a phase voltage under a natural coordinate system, inputting the phase voltage into a pulse width modulation module based on carrier waves, generating a switching signal for controlling each phase of the motor, and enabling an inverter to control the motor according to the switching signal. By means of the method, fault-tolerant control over the motor under the high-resistance contact fault is achieved, and the copper loss of the motor is reduced.

Description

Technical Field

[0001] This application relates to the field of permanent magnet synchronous motors, and in particular to a fault-tolerant control method and device for high-resistance contact faults in a five-phase permanent magnet synchronous motor. Background Technology

[0002] The five-phase permanent magnet synchronous motor is a multiphase AC motor that combines the high efficiency and high power density characteristics of permanent magnet synchronous motors with the high reliability and low torque ripple advantages of multiphase motors. It has five-phase windings, which can significantly improve fault tolerance.

[0003] When a high-resistance contact fault occurs in a five-phase permanent magnet synchronous motor, it can lead to motor torque pulsation, reduced efficiency, and localized temperature rise. In severe cases, it can even cause wires to melt and develop into an open circuit fault. If hysteresis control is used to change the inverter's switching state based on the current to achieve fault-tolerant control of the motor, it introduces high-order harmonics, resulting in excessive copper losses. Summary of the Invention

[0004] The purpose of this application is to provide a fault-tolerant control method and device for high-resistance contact faults in a five-phase permanent magnet synchronous motor, which can realize fault-tolerant control of the motor under high-resistance contact faults and reduce the copper loss of the motor.

[0005] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor, comprising: Obtain adjustment commands for controlling the motor; the adjustment commands indicate the target torque output by the motor. When a high-resistance contact fault occurs in the motor, a reconstruction coefficient matrix is ​​obtained based on the healthy phase current of the motor and the current reference value allocation matrix. Then, optimization targets are established for the motor under different target torques according to the reconstruction coefficient matrix to obtain the optimized reconstruction rotating orthogonal coordinate system current. When the target torque does not exceed the preset torque, the optimization target is to obtain the reconstruction rotating orthogonal coordinate system current with the minimum copper loss of the indicating motor. When the target torque exceeds the preset torque, the optimization target is to obtain the reconstruction rotating orthogonal coordinate system current with the maximum torque value of the indicating motor. The actual rotating orthogonal coordinate system current of the motor is obtained, and the difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current is used as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage; the rotating orthogonal coordinate system voltage is input into the pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage. The reconstructed rotating orthogonal coordinate system voltage is transformed into the phase voltage in the natural coordinate system, and the phase voltage is input into the carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor. This enables the inverter to control the motor to maintain a stable target torque under high-resistance contact faults based on the switching signals.

[0006] In some implementations, the current reference value allocation matrix is ​​reconstructed based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix, including: The third harmonic subspace current is configured based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix on the αβ axis, where the elements in the current reconstruction matrix of the fundamental current on the α3β3 axis are represented by the product of a fault tolerance coefficient and the fundamental current on the αβ axis.

[0007] In some implementations, optimization targets are established for the motor under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current, including: If the target torque does not exceed the preset torque and the high-resistance contact fault occurs in phase A of the motor, the phase A current is obtained by reconstructing the fundamental and third harmonic subspace currents of phase A. To ensure that the motor with faults maintains minimal copper loss, the relevant fault tolerance coefficient for adjusting phase A in the current reconstruction matrix is ​​set to a negative value, and other fault tolerance coefficients are set to 0. The formula for calculating the motor copper loss is determined based on the phase A current and the healthy phase current.

[0008] The derivative of the formula for calculating motor copper loss is derived so that the partial derivative of the motor copper loss with respect to the relevant fault tolerance coefficient of phase A is equal to 0, in order to obtain the optimization target of minimizing the motor copper loss when the target torque does not exceed the preset torque.

[0009] In some implementations, fault tolerance control methods also include: The phase currents of each phase of the motor are rearranged according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current; By substituting the reconstructed rotating orthogonal coordinate system current into the Parker and Clarke transformations of the five-phase motor, the target phase current with the goal of minimizing the copper loss of the motor is determined.

[0010] In some implementations, fault tolerance control methods also include: Determine the current amplitude of each phase other than phase A. If the current amplitudes of phases B and E are both greater than the current amplitudes of phases C and D, determine the first torque derating factor of the motor based on the current amplitude of phase B. Based on the product of the first torque derating factor and the rated torque of the motor, the first maximum torque output of the motor is determined when the optimization objective is to minimize the copper loss of the motor. The first maximum torque output satisfies the following relationship: ; In the formula, T MCLmax Indicates the first maximum torque output. a MCL This represents the first torque derating factor. T rated Indicates the rated torque. K α3α1 This represents the relevant fault tolerance coefficient.

[0011] In some implementations, optimization targets are established for the motor under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current. Other methods include: If the target torque exceeds the preset torque and the high-resistance contact fault occurs in phase A, adjust the relevant fault tolerance coefficient in the current reconstruction matrix to make the average copper loss after definite integration of the healthy phase current consistent within the range of 0 to 2π, so as to obtain the optimized target of maximizing the motor torque value when the target torque exceeds the preset torque.

[0012] In some implementations, fault tolerance control methods also include: The phase currents of each phase of the motor are rearranged according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current; By substituting the reconstructed rotating orthogonal coordinate system current into the Parker and Clarke transformations of the five-phase motor, the target phase current with the goal of maximizing the motor's torque value is determined.

[0013] In some implementations, fault tolerance control methods also include: Determine the current amplitude of each phase other than phase A. If the current amplitude of each phase is the same, determine the second torque derating factor of the motor. Based on the product of the second torque derating factor and the rated torque of the motor, the second maximum torque output of the motor is determined when the optimization objective is to maximize the motor torque value. The second maximum torque output satisfies the following relationship: ; In the formula, T MTMCLmax This indicates the second maximum torque output. a MTMCL This represents the second torque derating factor. T rated Indicates the rated torque. K β3β1 This represents the relevant fault tolerance coefficient.

[0014] Secondly, this application provides a fault-tolerant control device for a five-phase permanent magnet synchronous motor with high-resistance contact faults. The device includes an instruction receiving module, a current reconstruction module, a voltage reconstruction module, a signal generation module, and an inverter. The instruction receiving module acquires control commands for the motor, indicating the target torque output by the motor. The current reconstruction module, when a high-resistance contact fault occurs in the motor, reconstructs a current reference value allocation matrix based on the healthy phase current of the motor to obtain a reconstruction coefficient matrix. Based on the reconstruction coefficient matrix, optimization targets are established for the motor under different target torques to obtain optimized reconstructed rotating orthogonal coordinate system currents. When the target torque does not exceed a preset torque, the optimization target is to obtain the reconstructed rotating orthogonal coordinate system current that indicates the minimum copper loss of the motor. When the target torque exceeds the preset torque, the optimization... The objective is to obtain the reconstructed rotating orthogonal coordinate system current that maximizes the indicated motor torque value. The voltage reconstruction module is used to obtain the actual rotating orthogonal coordinate system current of the motor. The difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current is used as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage. The rotating orthogonal coordinate system voltage is input into a pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage. The signal generation module is used to transform the rotating orthogonal coordinate system voltage into the phase voltage in the natural coordinate system through Clarke transform. The phase voltage is then input into the carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor. The inverter outputs high-frequency switching pulses for controlling the motor based on the switching signals, so that the motor maintains a stable target torque under high-resistance contact faults.

[0015] Thirdly, this application provides a computer device including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor executes any of the above-mentioned fault-tolerant control methods for high-resistance contact faults in five-phase permanent magnet synchronous motors. The fault-tolerant control method provided in this application obtains the reconstructed rotating orthogonal coordinate system current based on the relationship between the target torque and the preset torque, obtains the reconstructed rotating orthogonal coordinate system voltage using a proportional resonant controller and a pre-established voltage reconstruction model, and transforms the reconstructed rotating orthogonal coordinate system voltage into the phase voltage in the natural coordinate system to generate switching signals for controlling each phase of the motor. This enables the inverter to control the motor according to the switching signals, maintaining the stability of the target torque of the motor under high-resistance contact faults while reducing the copper loss of the motor, thus achieving fault-tolerant control of the motor under high-resistance contact faults. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a high-resistance contact fault occurring in a five-phase permanent magnet synchronous motor in an embodiment of this application; Figure 2 This is a flowchart of the fault-tolerant control method in the embodiments of this application; Figure 3 A flowchart illustrating the optimization objective of minimizing copper loss in the motor as described in this application embodiment; Figure 4 This is a first flowchart for determining the target phase current in an embodiment of this application; Figure 5 This is a flowchart illustrating the determination of the first maximum torque output in an embodiment of this application; Figure 6 A flowchart illustrating the optimization objective of maximizing the motor torque value in this application embodiment; Figure 7 This is a second flowchart for determining the target phase current in an embodiment of this application; Figure 8 This is a flowchart illustrating the determination of the second maximum torque output in an embodiment of this application; Figure 9 This is a torque fluctuation diagram with the optimization objective of minimizing copper loss in the embodiments of this application; Figure 10 This is a torque fluctuation diagram with the maximum torque value as the optimization target in the embodiments of this application; Figure 11 This is a comparison diagram of copper loss in various schemes in the embodiments of this application; Figure 12 This is a schematic diagram of the fault-tolerant control device in the embodiments of this application; Figure 13 This is a schematic diagram of a computer device in an embodiment of this application. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0018] It should be noted that the terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates at least two. "Comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Connected" or "linked" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0019] This application provides a fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor. The high-resistance contact fault refers to a fault in which poor contact at the contact point leads to an abnormal increase in resistance. Fault-tolerant control means that when a fault occurs in a five-phase permanent magnet synchronous motor, it can still maintain its core functions or performance and avoid catastrophic consequences (such as shutdown, loss of control, or safety accidents).

[0020] like Figure 1 As shown, when a high-resistance contact fault occurs in phase A, the stator resistance satisfies the following relationship:

[0021] In the formula, R sf It is the stator resistance matrix under high-resistance contact fault, R s It is the phase resistance, R f It is the contact resistance in the phase with high resistance contact fault. Understandably, the resistance of phase A is higher than that of the phase under healthy conditions.

[0022] like Figure 2 As shown, in some embodiments, the fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor includes the following steps: Step S201: Obtain adjustment commands for controlling the motor.

[0023] The adjustment command is used to indicate the target torque output by the motor.

[0024] Step S202: When a high-resistance contact fault occurs in the motor, the reconstruction coefficient matrix is ​​obtained based on the healthy phase current of the motor to reconstruct the current reference value allocation matrix. Based on the reconstruction coefficient matrix, optimization targets are established for the motor under different target torques to obtain the optimized reconstructed rotating orthogonal coordinate system current.

[0025] It should be noted that a healthy phase refers to a phase that does not experience electrical and / or mechanical faults such as short circuits, open circuits, or high-resistance contact faults. In a healthy state, the vector space of a five-phase permanent magnet synchronous motor can be decomposed into mutually orthogonal subspaces through decoupling transformation. These subspaces include a fundamental subspace and a harmonic subspace. The fundamental subspace contains the fundamental current, which generates a healthy rotating magnetic field and is therefore the core component of the motor's output torque. The harmonic subspace contains harmonic currents, which optimize the magnetic field distribution (e.g., suppressing torque ripple). However, since the fundamental and harmonic subspaces are orthogonal, the harmonic currents do not interfere with the normal operation of the fundamental current.

[0026] When a high-resistance contact fault occurs in the motor, the fundamental subspace and the harmonic subspace are coupled to each other. The fundamental magnetomotive force generated by the fundamental current cannot form a complete circular rotating magnetic field. The harmonic magnetomotive force generated by the harmonic current affects the fundamental magnetomotive force, resulting in torque pulsation.

[0027] Therefore, it is necessary to synthesize a more circular composite magnetic field by combining the third harmonic magnetic field generated by the third harmonic current with the fundamental magnetic field to compensate for the magnetic field distortion caused by the fault and maintain the motor's output torque capability.

[0028] In some implementations, when reconstructing the current reference value allocation matrix based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix, the third harmonic subspace current is configured based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix on the αβ axis. The elements in the current reconstruction matrix of the fundamental current on the α3β3 axis are represented by the product of a tolerance coefficient and the fundamental current on the αβ axis.

[0029] It should be noted that the αβ axis is a two-phase stationary orthogonal coordinate system, and the α3β3 axis is the third harmonic subplane obtained by transforming the αβ axis through the third harmonic transformation matrix.

[0030] Specifically, the current reconstruction matrix of the fundamental current on the α3β3 axis satisfies the following relationship:

[0031] In the formula, i α1 and i β1 Let α1 and β1 represent the fundamental currents on the fundamental subspace, respectively. i α31 and i β31 This represents the fundamental current in the third harmonic subspace. K fαβ Represents the fault tolerance coefficient. K xy This indicates the current reconstruction coefficient that maps the y-axis current to the x-axis (x, y = α1, α3, β1, β3).

[0032] By setting up the above, the third harmonic subspace current is mapped to the αβ axis to generate a reconstruction coefficient matrix, thereby optimizing the current distribution and decoupling the harmonics from the fundamental frequency.

[0033] Step S203: Determine whether the target torque exceeds the preset torque. If not, proceed to step S204; if yes, proceed to step S205.

[0034] Step S204: The optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current that minimizes the copper loss of the indicating motor. After executing step S204, proceed to step S206.

[0035] Copper loss is the heat loss in an electric motor caused by the heating of conductors through which current flows.

[0036] It should be noted that since the third harmonic permanent magnet flux linkage is zero, the magnetomotive force of the third harmonic subspace cannot generate the fundamental torque component. Therefore, no matter how much fundamental current is injected into the third harmonic subspace, the torque fluctuation will not be affected. However, copper loss is positively correlated with the effective value of the total current, which includes the fundamental and harmonic components. Therefore, by reconfiguring the phase currents, the amplitude of the total current can be optimized, thereby reducing the effective value of the total current and decreasing the copper loss of the five-phase motor.

[0037] like Figure 3 As shown, in some implementations, optimization targets are established for the motor under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current, including the following steps: Step S301: If the target torque does not exceed the preset torque and the high-resistance contact fault occurs in phase A of the motor, the phase A current is obtained by reconstructing the fundamental and third harmonic subspace currents of phase A.

[0038] The current in phase A satisfies the following relationship:

[0039] In the formula, i a This represents the current of phase A. i α1 This represents the fundamental current on the α1β1 axis of the fundamental subspace. i α3 This represents the current along the α3 axis in the third harmonic subspace.

[0040] From the above equation, we can see that the current in phase A is related to... i β3 The current on the shaft is irrelevant.

[0041] Step S302: Set the relevant fault tolerance coefficient of phase A in the current reconstruction matrix to a negative value, set other fault tolerance coefficients to 0, and determine the motor copper loss calculation formula based on the phase A current and the healthy phase current.

[0042] Specifically, K β3α1 , K β3β1 and K α3α1 Set it to 0, and K α3α1 Set to a negative value so that the copper loss of the motor is... i α1 and K α3α1 The following relationship must be satisfied:

[0043] In the formula, Pcu This indicates the copper loss of the motor. R s This represents the phase resistance of the motor. R f This represents the contact resistance in phase A. i n (n=a,b,c,d,e) represents the phase current of each phase. R add This indicates the fault contact resistance.

[0044] It should be noted that... K β3α1 , K β3β1 Setting it to 0 can avoid the aforementioned fault tolerance factor increasing copper loss, and because K α3β1 The values ​​of all of these will increase the current in phase A, therefore... K α3β1 Setting it to 0 can reduce copper losses by lowering the current in phase A. K α3α1 This is the only parameter in the embodiments of this application that can cancel the current on the α1 axis, therefore... K α3α1 Set to a negative value.

[0045] Step S303: Differentiate the formula for calculating motor copper loss so that the partial derivative of the motor copper loss with respect to the relevant fault tolerance coefficient of phase A is equal to 0, so as to obtain the optimization target of minimizing the motor copper loss when the target torque does not exceed the preset torque.

[0046] In this embodiment, the copper loss of the motor is reduced. K α3α1 The partial derivatives are equal to 0, and the following relationship is obtained:

[0047] The above formula represents the optimization objective of minimizing the copper loss of the motor.

[0048] Through the above steps, other fault tolerance factors that could increase copper losses are set to 0, and the fault tolerance factor that could offset the current on the α1 axis is set to a negative value, and by making... K α3α1 The partial derivative is 0, which gives the parameters for minimizing the copper loss of the motor, ensuring that the motor with the fault maintains the minimum copper loss.

[0049] It should be noted that if the motor is a surface-mounted permanent magnet synchronous motor, the electromagnetic torque under healthy conditions satisfies the following relationship:

[0050] In the formula, p represents the number of pole pairs of the motor. This represents the d-axis magnetic flux linkage generated by the permanent magnet. This represents the component of the stator current vector of the motor along the q-axis in a rotating orthogonal coordinate system.

[0051] like Figure 4 As shown, in some implementations, the fault-tolerant control method further includes the following steps: Step S401: Rearrange the phase currents of each phase of the motor according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current.

[0052] The current in the reconstructed rotating orthogonal coordinate system satisfies the following relationship:

[0053] Step S402: Substitute the reconstructed rotating orthogonal coordinate system current into the Parker and Clark transformations of the five-phase motor to determine the target phase current with the goal of minimizing the copper loss of the motor.

[0054] Among them, the Parker variation is used to realize the conversion between the αβ axis current and the dq axis current, and the Clark variation is used to realize the conversion between the five-phase phase current and the αβ axis current.

[0055] Through the above steps, using Parker and Clarke variations, the conversion between five-phase currents, αβ-axis currents, and dq-axis currents is achieved, so as to determine the target phase current with the goal of minimizing the copper loss of the motor.

[0056] like Figure 5 As shown, in some implementations, the fault-tolerant control method further includes the following steps: Step S501: Determine the current amplitude of each phase other than phase A.

[0057] The target phase current satisfies the following relationship:

[0058] In the formula, i xMCL (x=a,b,...,e) represents the phase current change with the optimization objective of minimizing the copper loss of the motor, λ xMCL (x=b,...,e) represents the phase offset of the phase current with the optimization objective of minimizing the copper loss of the motor. i ql This represents the component of the stator current vector of the motor along the q-axis in a rotating orthogonal coordinate system.

[0059] According to the above formula, combined with the phase offset λ xMCL Afterwards, the current amplitudes of phase B and phase E are higher than those of phase C and phase D. The current amplitude of phase B can be used as a key parameter to determine the first torque derating factor of the motor.

[0060] Step S502: If the current amplitudes of phase B and phase E are both greater than the current amplitudes of phase C and phase D, determine the first torque derating factor of the motor based on the current amplitude of phase B.

[0061] Step S503: Determine the first maximum torque output of the motor when the optimization objective is to minimize the copper loss of the motor, based on the product of the first torque derating factor and the rated torque of the motor.

[0062] The first maximum torque output satisfies the following relationship: ; In the formula, T MCLmax Indicates the first maximum torque output. a MCL This represents the first torque derating factor. T rated Indicates the rated torque. K α3α1 This represents the relevant fault tolerance coefficient.

[0063] Through the above steps, the optimization objective is to obtain the reconfigured rotating orthogonal coordinate system current that minimizes the copper loss of the indicated motor, thereby keeping the motor with minimal copper loss to avoid the risk of motor overheating due to excessive copper loss in the normal phases other than the faulty phase.

[0064] Step S205: The optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current that maximizes the torque value of the indicated motor.

[0065] It should be noted that although the motor maintains minimal copper losses, the current amplitudes of the remaining healthy phases (excluding the faulty phase) are inconsistent, leading to excessive current in some phases. Since the faulty phase can still be effectively controlled, the system retains four degrees of freedom: two for constructing the rotating magnetic field in the base plane, one for satisfying the minimum copper loss constraint, and the remaining degree of freedom for adjusting the current amplitude of the healthy phases. Therefore, when the target torque exceeds the preset torque, the current amplitude of the healthy phases is adjusted to ensure uniform current amplitude across all healthy phases, thereby ensuring higher torque output from the motor.

[0066] In some implementations, optimization targets are established for motors under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current. If the target torque exceeds the preset torque and the high-resistance contact fault occurs in phase A, the relevant fault tolerance coefficients in the current reconstruction matrix are adjusted so that the average copper loss after definite integration of the healthy phase current is consistent within the range of 0 to 2π, so as to obtain the optimization target where the motor torque value is maximized when the target torque exceeds the preset torque.

[0067] like Figure 6As shown, in some implementations, the optimization objective of maximizing the motor torque value when the target torque exceeds the preset torque specifically includes the following steps: Step S601: Adjust the current reconstruction coefficient. K α3β3 , K β3α1 and K β3β1 To obtain the relationship between the phase currents.

[0068] The relationship between the phase currents is as follows: K α3β3 , K β3α1 and K β3β1 The corresponding limit conditions and the relationship between the phase currents are as follows:

[0069] In the formula, i n (n=b,c,d,e) represents the phase currents other than phase A.

[0070] Step S602: Perform a definite integral on the relationship between phase currents within the range of 0 to 2π to obtain a formula containing only... K α3β3 , K β3α1 and K β3β1 Average copper loss per phase.

[0071] The definite integral of the relationship between the phase currents satisfies the following relationship:

[0072] Step S603: Solve the relationship between the integrated phase currents, and make... K α3β1 and K β3α1 All values ​​are 0, in order to obtain the optimal target where the motor torque value is maximized when the target torque exceeds the preset torque.

[0073] in, K β3β1 and K α3α1 The relationship between them satisfies the following equation:

[0074] Increase through the above steps K β3β1This ensures that the current amplitude of each healthy phase is consistent, expands the safe torque range of the motor while keeping copper losses low, and improves the motor's operational stability.

[0075] like Figure 7 As shown, in some implementations, the fault-tolerant control method further includes the following steps: Step S701: Rearrange the phase currents of each phase of the motor according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current.

[0076] The current in the reconstructed rotating orthogonal coordinate system satisfies the following relationship:

[0077] Step S702: Substitute the reconstructed rotating orthogonal coordinate system current into the Parker and Clark transformations of the five-phase motor to determine the target phase current with the maximum torque value of the motor as the optimization objective.

[0078] Through the above steps, using Parker and Clarke variations, the conversion between five-phase currents, αβ-axis currents, and dq-axis currents is achieved, so as to determine the target phase current with the optimization objective of maximizing the motor torque value.

[0079] like Figure 8 As shown, in some implementations, the fault-tolerant control method further includes the following steps: Step S801: Determine the current amplitude of each phase other than phase A.

[0080] The target phase current satisfies the following relationship:

[0081] In the formula, i xMTMCL (x=a,b,...,e) represents the phase current change with the optimization objective of maximizing the motor torque value, λ xMTMCL (x=b,...,e) represents the phase offset of the phase current with the optimization objective of maximizing the motor torque value. i ql This represents the component of the stator current vector of the motor along the q-axis in a rotating orthogonal coordinate system.

[0082] Step S802: If the current amplitude of the other phases is the same, determine the second torque derating factor of the motor.

[0083] Step S803: Determine the second maximum torque output of the motor when the optimization objective is to maximize the motor's torque value, based on the product of the second torque derating factor and the rated torque of the motor.

[0084] The second maximum torque output satisfies the following relationship:

[0085] In the formula, T MTMCLmax This indicates the second maximum torque output. a MTMCL This represents the second torque derating factor. T rated Indicates the rated torque. K β3β1 This represents the relevant fault tolerance coefficient.

[0086] Through the above steps, the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current that maximizes the torque value of the indicated motor, so that the current amplitude of each healthy phase is consistent. This allows the motor to have a large torque with low copper loss, thereby avoiding the risk of motor overheating due to excessive copper loss in the other normal phases (excluding the faulty phase) and improving motor efficiency.

[0087] Step S206: Obtain the actual rotating orthogonal coordinate system current of the motor, use the difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage, and input the rotating orthogonal coordinate system voltage into the pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage.

[0088] Step S207: The reconstructed rotating orthogonal coordinate system voltage is transformed into the phase voltage in the natural coordinate system, and the phase voltage is input into the carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor, so that the inverter controls the motor to maintain a stable target torque under high-resistance contact fault according to the switching signals.

[0089] If the faulty phase is phase A, the phase voltage in the natural coordinate system satisfies the following relationship:

[0090] In the formula, to These represent the phase voltages from phase A to phase E, respectively.

[0091] It should be noted that the increased resistance in phase A due to the fault only affects the phase voltage related to the phase current. Therefore, the effect can be eliminated by changing the coefficient, allowing the motor to maintain the target torque or current even under fault conditions. Furthermore, since the phase currents of a five-phase motor satisfy Kirchhoff's current law, four current controllers can be used to control the fifth phase current by controlling the four phase currents, thus saving computational resources.

[0092] By using the Clarke transform matrix and reconstructing the current in the rotating orthogonal coordinate system, the voltage equation in the αβ coordinate system can be obtained. This equation satisfies the following relationship:

[0093] From the above relationship, it can be seen that using... i α1 and i α3 Each = Compensation u α3 and u α1 It can achieve voltage reconfiguration.

[0094] The fault-tolerant control method provided in this application obtains the reconstructed rotating orthogonal coordinate system current based on the relationship between the target torque and the preset torque, obtains the reconstructed rotating orthogonal coordinate system voltage using a proportional resonant controller and a pre-established voltage reconstruction model, and transforms the reconstructed rotating orthogonal coordinate system voltage into the phase voltage in the natural coordinate system to generate switching signals for controlling each phase of the motor. This enables the inverter to control the motor according to the switching signals, maintaining the stability of the target torque of the motor under high-resistance contact faults while reducing the copper loss of the motor, thus achieving fault-tolerant control of the motor under high-resistance contact faults.

[0095] like Figures 9 to 11 As shown, for example, when a 10Ω high-resistance contact fault occurs in phase A and the five-phase permanent magnet synchronous motor is running at 500rpm and 1.5Nm torque, the effective value of the phase current and the copper loss are compared when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current with the minimum copper loss of the indicating motor, and when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current with the maximum torque value of the indicating motor.

[0096] It should be noted that, Figure 11 From left to right, the figures show the copper losses when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current that minimizes the copper loss of the indicating motor, and the copper losses when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current that maximizes the torque value of the indicating motor.

[0097] Depend on Figures 9 to 11 It can be seen that when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current with the minimum copper loss of the indicating motor, and when the optimization objective is to obtain the reconstructed rotating orthogonal coordinate system current with the maximum torque value of the indicating motor, the torque fluctuation of both is stable and the copper loss is low.

[0098] The above examples demonstrate that the fault-tolerant control method in the embodiments of this application can effectively reduce copper losses and improve motor efficiency under high-resistance contact fault conditions.

[0099] It should be noted that the fault phase in this application is phase A. If the fault phase is another phase, it can be compared with the method steps in this application.

[0100] like Figure 12As shown, this application also provides a fault-tolerant control device 100 for high-resistance contact faults in a five-phase permanent magnet synchronous motor, which includes a command receiving module 11, a current reconstruction module 12, a voltage reconstruction module 13, a signal generation module 14, and an inverter 15. The command receiving module 11 is used to acquire adjustment commands for controlling the motor, and the adjustment commands are used to indicate the target torque output by the motor.

[0101] The current reconfiguration module 12 is used to reconfigure the current reference value allocation matrix based on the healthy phase current of the motor when a high-resistance contact fault occurs in the motor, so as to obtain the reconfiguration coefficient matrix. The current reconfiguration module 12 is also used to establish optimization targets for the motor under different target torques according to the reconfiguration coefficient matrix, so as to obtain the optimized reconfigured rotating orthogonal coordinate system current. When the target torque does not exceed the preset torque, the optimization target is to obtain the reconfigured rotating orthogonal coordinate system current with the minimum copper loss of the indicated motor; when the target torque exceeds the preset torque, the optimization target is to obtain the reconfigured rotating orthogonal coordinate system current with the maximum torque value of the indicated motor.

[0102] The voltage reconstruction module 13 is used to obtain the actual rotating orthogonal coordinate system current of the motor, and uses the difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage; the rotating orthogonal coordinate system voltage is input to the pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage.

[0103] The signal generation module 14 is used to transform the voltage in the rotating orthogonal coordinate system into the phase voltage in the natural coordinate system through the Clarke transformation, and input the phase voltage into the carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor.

[0104] Inverter 15 is used to output high-frequency switching pulses to control the motor according to the switching signal, so that the motor can maintain a stable target torque under high-resistance contact faults.

[0105] The fault-tolerant control device 100 provided in this application obtains a reconstruction coefficient matrix through the current reconstruction module 12, and establishes an optimization target for the motor under different target torques based on the reconstruction coefficient matrix to obtain the reconstructed rotating orthogonal coordinate system current. The voltage reconstruction module 13 obtains the reconstructed rotating orthogonal coordinate system voltage. The signal generation module 14 generates switching signals for controlling each phase of the motor based on the rotating orthogonal coordinate system voltage, so as to control the inverter 15 to output high-frequency switching pulses to control the motor. While maintaining the stability of the target torque of the motor under high-resistance contact faults, it reduces the copper loss of the motor and realizes fault-tolerant control of the motor under high-resistance contact faults.

[0106] like Figure 13As shown, this application also provides a computer device 200, which includes a memory 21 and a processor 22. The memory 21 stores a computer program. When the computer program is executed by the processor 22, the processor 22 executes the above-mentioned fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor.

[0107] Specifically, processor 22 may include a central processing unit, or an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement embodiments of the present invention.

[0108] In some implementations, memory 21 may include a large-capacity memory for data or instructions.

[0109] For example, the memory includes a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, a universal serial bus (USB) drive, or any combination of the above-mentioned memory.

[0110] For example, memory 21 may be located inside or outside a computer device.

[0111] In some possible implementations, the computer device 200 also includes a communication interface 23 and a bus 24. The processor 22, memory 21, and communication interface 23 are connected via the bus 24 and communicate with each other.

[0112] The communication interface 23 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0113] Bus 24 includes hardware and / or software that couples components of computer device 200 together. For example, and not to limit, bus 24 may include an accelerated graphics port or other graphics bus, an enhanced industry standard architecture bus, a front-side bus, a low pin count bus, a memory bus, or other suitable bus or any combination of the above buses.

[0114] This application also provides a computer-readable storage medium (not shown) storing a computer program that, when executed by a processor, implements the steps of the above-described fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor.

[0115] Computer-readable storage media include, but are not limited to, electronic, magnetic, optical, infrared, or other physical storage devices or apparatuses that may contain or store information such as executable instructions, data, etc. More specific examples of computer-readable storage media include electrical connections based on one or more wires, RAM (Random Access Memory), volatile memory, non-volatile memory, flash memory, storage drives (such as hard disk drives), SSDs (Solid State Disks), any type of storage disk (such as optical discs), or similar memory, or any suitable combination of the foregoing.

[0116] It should be noted that, in order to avoid repetition and improve the conciseness of the manual, the descriptions of the same or substantially similar technical features, structures or method steps in different implementations may be simplified or omitted.

[0117] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A fault-tolerant control method for high-resistance contact faults in a five-phase permanent magnet synchronous motor, characterized in that, Obtain adjustment commands for controlling the motor, the adjustment commands indicating the target torque output by the motor; When the motor experiences a high-resistance contact fault, a reconstruction coefficient matrix is ​​obtained based on the healthy phase current of the motor and the current reference value allocation matrix. Optimization targets are then established for the motor under different target torques according to the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current. When the target torque does not exceed a preset torque, the optimization target is to obtain the reconstructed rotating orthogonal coordinate system current that indicates the minimum copper loss of the motor. When the target torque exceeds the preset torque, the optimization target is to obtain the reconstructed rotating orthogonal coordinate system current that indicates the maximum torque value of the motor. The actual rotating orthogonal coordinate system current of the motor is obtained, and the difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current is used as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage; the rotating orthogonal coordinate system voltage is input into a pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage. The reconstructed rotating orthogonal coordinate system voltage is transformed into a phase voltage in the natural coordinate system, and the phase voltage is input into a carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor. The inverter controls the motor to maintain the target torque smoothly under the high-resistance contact fault according to the switching signals.

2. The fault-tolerant control method according to claim 1, characterized in that, The method of reconstructing the current reference value allocation matrix based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix includes: The third harmonic subspace current is configured based on the healthy phase current of the motor to obtain the reconstruction coefficient matrix on the αβ axis, wherein the elements in the current reconstruction matrix of the fundamental current on the α3β3 axis are represented by a fault tolerance coefficient multiplied by the fundamental current on the αβ axis.

3. The fault-tolerant control method according to claim 2, characterized in that, The step of establishing optimization targets for the motor under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current includes: If the target torque does not exceed the preset torque, and the high-resistance contact fault occurs in phase A of the motor, the phase A current is reconstructed based on the fundamental and third harmonic subspace currents of phase A. To ensure that the motor with faults maintains minimal copper loss, the relevant fault tolerance coefficient of the A phase in the current reconstruction matrix is ​​set to a negative value, and other fault tolerance coefficients are set to 0. The motor copper loss calculation formula is determined based on the A phase current and the healthy phase current. The derivative of the motor copper loss calculation formula is taken so that the partial derivative of the motor copper loss with respect to the relevant fault tolerance coefficient of phase A is equal to 0, so as to obtain the optimization target of minimizing the motor copper loss when the target torque does not exceed the preset torque.

4. The fault-tolerant control method according to claim 3, characterized in that, The fault-tolerant control method further includes: The phase currents of each phase of the motor are rearranged according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current; The reconstructed rotating orthogonal coordinate system current is substituted into the Parker and Clarke transformations of the five-phase motor to determine the target phase current with the minimum copper loss of the motor as the optimization objective.

5. The fault-tolerant control method according to claim 3, characterized in that, The fault-tolerant control method further includes: Determine the current amplitude of each phase other than phase A. If the current amplitude of phase B and phase E is greater than the current amplitude of phase C and phase D, determine the first torque derating factor of the motor based on the current amplitude of phase B. Based on the product of the first torque derating factor and the rated torque of the motor, the first maximum torque output of the motor is determined when the optimization objective is to minimize the copper loss of the motor. The first maximum torque output satisfies the following relationship: ； In the formula, T MCLmax This indicates the first maximum torque output. a MCL This represents the first torque derating factor. T rated This indicates the rated torque. K α3α1 is the relevant fault tolerance coefficient.

6. The fault-tolerant control method according to claim 2, characterized in that, The step of establishing optimization targets for the motor under different target torques based on the reconstruction coefficient matrix to obtain the optimized reconstructed rotating orthogonal coordinate system current further includes: If the target torque exceeds the preset torque and the high-resistance contact fault occurs in phase A, adjust the relevant fault tolerance coefficient in the current reconstruction matrix so that the average copper loss after definite integration of the healthy phase current in the range of 0 to 2π is consistent, so as to obtain the optimized target where the motor torque value is maximized when the target torque exceeds the preset torque.

7. The fault-tolerant control method according to claim 6, characterized in that, The fault-tolerant control method further includes: The phase currents of each phase of the motor are rearranged according to the current reconstruction coefficient to obtain the reconstructed rotating orthogonal coordinate system current; The reconstructed rotating orthogonal coordinate system current is substituted into the Parker and Clarke transformations of the five-phase motor to determine the target phase current with the maximum torque value of the motor as the optimization objective.

8. The fault-tolerant control method according to claim 6, characterized in that, The fault-tolerant control method further includes: Determine the current amplitude of each phase other than phase A. If the current amplitude of each phase is the same, determine the second torque derating factor of the motor. Based on the product of the second torque derating factor and the rated torque of the motor, the second maximum torque output of the motor is determined when the optimization objective is to maximize the torque value of the motor. The second maximum torque output satisfies the following relationship: ； In the formula, T MTMCLmax This indicates the second maximum torque output. a MTMCL This represents the second torque derating factor. T rated This indicates the rated torque. K β3β1 is the relevant fault tolerance coefficient.

9. A fault-tolerant control device for high-resistance contact faults in a five-phase permanent magnet synchronous motor, characterized in that, include: The instruction receiving module is used to acquire adjustment instructions for controlling the motor, the adjustment instructions being used to indicate the target torque output by the motor; A current reconfiguration module is used to reconstruct a current reference value allocation matrix based on the healthy phase current of the motor when a high-resistance contact fault occurs in the motor, so as to obtain a reconfiguration coefficient matrix; and to establish optimization targets for the motor under different target torques according to the reconfiguration coefficient matrix, so as to obtain optimized reconfigured rotating orthogonal coordinate system currents; when the target torque does not exceed the preset torque, the optimization target is to obtain the reconfigured rotating orthogonal coordinate system current that indicates the minimum copper loss of the motor; when the target torque exceeds the preset torque, the optimization target is to obtain the reconfigured rotating orthogonal coordinate system current that indicates the maximum torque value of the motor. The voltage reconstruction module is used to obtain the actual rotating orthogonal coordinate system current of the motor, and use the difference between the reconstructed rotating orthogonal coordinate system current and the actual rotating orthogonal coordinate system current as the input of the proportional resonant controller to obtain the rotating orthogonal coordinate system voltage; the rotating orthogonal coordinate system voltage is input to a pre-established voltage reconstruction model to obtain the reconstructed rotating orthogonal coordinate system voltage. The signal generation module is used to transform the voltage in the rotating orthogonal coordinate system into the phase voltage in the natural coordinate system through Clarke transformation, and input the phase voltage into the carrier-based pulse width modulation module to generate switching signals for controlling each phase of the motor. The inverter outputs high-frequency switching pulses to control the motor based on the switching signal, so that the motor maintains a stable target torque under high-resistance contact faults.

10. A computer device, characterized in that, include: A memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the fault-tolerant control method for high-resistance contact faults of a five-phase permanent magnet synchronous motor as described in any one of claims 1-8.

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