Gait control method and device for permanent magnet synchronous motor resolver fault and vehicle

Abstract

The application provides a limp control method and device for permanent magnet synchronous motor resolver failure and a vehicle, and relates to the technical field of permanent magnet synchronous motor control. The method comprises the following steps: when detecting the resolver failure, recording the first angle and the first electrical angular velocity of the permanent magnet synchronous motor at the moment before the failure, and controlling to enter the limp mode; controlling the permanent magnet synchronous motor in the preset time transition stage according to the first angle, the first electrical angular velocity and the current of the permanent magnet synchronous motor collected in real time, obtaining the second angle and the second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition stage; injecting a high-frequency voltage, controlling the permanent magnet synchronous motor with the second angle and the second electrical angular velocity as initial values, realizing normal limp mode driving, inserting a coherent transition stage in the time dimension, maintaining the continuity of the control angle and the electrical angular velocity, effectively avoiding the angle jump and the current and voltage impact caused by the angle jump, and ensuring the stable operation of the vehicle.

Description

Technical Field

[0001] This application relates to the field of permanent magnet synchronous motor control technology, specifically to a limp control method, device, and vehicle for a permanent magnet synchronous motor rotary transformer fault. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are increasingly widely used in new energy vehicles due to their simple structure, high power density, reliable performance, and high operating efficiency. The position signal of a PMSM is typically obtained through a resolver, serving as a crucial control parameter for the motor controller. However, resolvers operate in complex environments, especially in high-voltage systems, further complicating the process. If the resolver's sampling has a significant error or if its hardware malfunctions, the motor's position and speed signals cannot be read. Consequently, the motor controller cannot obtain these critical control parameters, leading to malfunctions in the electric drive system and potential safety hazards.

[0003] Currently, at the instant the motor enters limp mode after a resolver failure, the current motor control angle switches from the resolver angle to the high-frequency injection (HFI) angle. This sudden angle change causes variations in motor voltage and current, which can easily lead to overcurrent. Furthermore, the switched HFI angle requires a convergence process, and fluctuations in current and voltage will also cause fluctuations in the HFI angle. Summary of the Invention

[0004] In view of this, this application provides a limp control method, device and vehicle for a permanent magnet synchronous motor rotary transformer fault. By smoothly connecting the switching process through transition control, the current and voltage fluctuations caused by sudden angle changes are reduced, and the stability of motor control is improved.

[0005] To achieve the above objectives, this application provides the following technical solution: a limp-mode control method for a permanent magnet synchronous motor with a rotary transformer fault, comprising: when a rotary transformer fault is detected, recording the first angle and first electrical angular velocity of the permanent magnet synchronous motor at the instant before the fault, and controlling it to enter a limp-mode; performing a transition phase control on the permanent magnet synchronous motor for a preset time based on the first angle, the first electrical angular velocity, and the current of the permanent magnet synchronous motor collected in real time, and obtaining the second angle and second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase; injecting a high-frequency voltage, and controlling the permanent magnet synchronous motor with the second angle and the second electrical angular velocity as initial values ​​to achieve normal limp-mode operation.

[0006] In one embodiment of this application, the step of performing a transition phase control of the permanent magnet synchronous motor for a preset time based on the first angle, the first electrical angular velocity, and the real-time acquired current of the permanent magnet synchronous motor includes: performing time integration based on the first electrical angular velocity to obtain the transition control angle of the permanent magnet synchronous motor; using the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition phase, respectively, and performing transition phase control within a preset time period in combination with the first angle and the real-time acquired current of the permanent magnet synchronous motor.

[0007] In one embodiment of this application, the step of using the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition stage, respectively, and combining the first angle and the real-time acquired current of the permanent magnet synchronous motor for transition stage control within a preset time includes: using the first electrical angular velocity as the initial electrical angular velocity of the transition stage, using the transition control angle as the initial angle of the transition stage, performing coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor according to the first angle within a preset time, outputting d-axis and q-axis voltages through the current loop in combination with the initial electrical angular velocity, and driving the permanent magnet synchronous motor through the inverter after coordinate transformation and space vector pulse width modulation in combination with the initial angle.

[0008] In one embodiment of this application, the injection of high-frequency voltage to control the permanent magnet synchronous motor using the second angle and the second electrical angular velocity as initial values ​​to achieve normal limp-mode operation includes: injecting high-frequency voltage into the d-axis of the permanent magnet synchronous motor using the second electrical angular velocity as an initial estimated electrical angular velocity and the second angle as an initial estimated angle; performing coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor according to the estimated angle to obtain the d-axis current and q-axis current; outputting d-axis and q-axis voltages through a current loop based on the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage; driving the permanent magnet synchronous motor through an inverter after coordinate transformation and space vector pulse width modulation based on the d-axis and q-axis voltages combined with the estimated angle; and updating the estimated electrical angular velocity and the estimated angle using a position observer based on the q-axis current and the high-frequency voltage.

[0009] In one embodiment of this application, updating the estimated electrical angular velocity and the estimated angle based on the q-axis current and the high-frequency voltage using a position observer includes: calculating half of the difference between the q-axis currents at adjacent times to obtain the q-axis current deviation; determining the angle error based on the determined sign of the high-frequency voltage and the q-axis current deviation; performing position observation based on the angle error to obtain the updated estimated electrical angular velocity; and performing integration and polarity determination on the estimated electrical angular velocity to obtain the updated estimated angle.

[0010] In one embodiment of this application, the step of obtaining an updated estimated electrical angular velocity by observing the position based on the angle error includes: processing the angle error through a first amplifier and a second amplifier respectively; superimposing the output of the first amplifier with the initial electrical angular velocity or the angle at the previous moment, summing it with the output of the second amplifier, and obtaining the updated estimated electrical angular velocity after low-pass filtering.

[0011] In one embodiment of this application, the step of integrating and polarity-discriminating the estimated electrical angular velocity to obtain an updated estimated angle includes: performing time integration on the estimated electrical angular velocity to obtain a high-frequency injection identification angle; determining the direct axis direction of the permanent magnet synchronous motor based on the d-axis current; and performing polarity synchronization processing on the identification angle based on the direction determination result to obtain an updated estimated angle.

[0012] In one embodiment of this application, the step of outputting d-axis and q-axis voltages through a current loop based on the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage includes: calculating half of the sum of the q-axis currents at adjacent time points to obtain the q-axis correction current; calculating half of the sum of the d-axis currents at adjacent time points to obtain the d-axis correction current; looking up a preset current relationship table based on the estimated electrical angular velocity and the required torque of the permanent magnet synchronous motor to obtain the d-axis required current and the q-axis required current; calculating the difference between the d-axis required current and the d-axis correction current, and obtaining the d-axis voltage after proportional-integral control and superposition with the high-frequency voltage; calculating the difference between the q-axis required current and the q-axis correction current, and obtaining the q-axis voltage after proportional-integral control.

[0013] As a second aspect of this application, this application also provides a limp-walk control device for a permanent magnet synchronous motor with a rotary transformer fault, comprising: a fault detection module, used to record the first angle and first electrical angular velocity of the permanent magnet synchronous motor at the instant before the fault is detected, and control it to enter a limp-walk mode; a transition control module, used to control the permanent magnet synchronous motor for a preset time transition phase based on the first angle, the first electrical angular velocity, and the current of the permanent magnet synchronous motor collected in real time, and to obtain the second angle and second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase; and an injection control module, used to inject a high-frequency voltage, and control the permanent magnet synchronous motor with the second angle and second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase as initial values ​​to achieve normal limp-walk mode operation.

[0014] As a third aspect of this application, this application also provides a vehicle, including: the aforementioned limp control device for a permanent magnet synchronous motor rotary transformer failure.

[0015] This application provides a limp-mode control method for a permanent magnet synchronous motor (PMSM) in case of a rotary transformer fault. When a rotary transformer fault is detected, the method records the first angle and first electrical angular velocity of the PMSM immediately before the fault and controls it to enter a limp-mode. Based on the first angle, first electrical angular velocity, and the real-time acquired current of the PMSM, a preset-time transition phase control is performed on the PMSM. The second angle and second electrical angular velocity of the PMSM at the end of the transition phase are then obtained. A high-frequency voltage is injected, and the PMSM is controlled using the second angle and second electrical angular velocity as initial values ​​to achieve normal limp-mode operation. This method inserts a continuous transition phase in the time dimension, using the continuous state before the fault as the control signal source and observation starting point, thereby maintaining the continuity of the control angle and electrical angular velocity signals at the moment of switching. This effectively avoids angle jumps and the resulting current and voltage surges, achieving a smooth and uninterrupted switch from the pre-fault state to the stable state, ensuring stable vehicle operation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a limp-off control method for a permanent magnet synchronous motor rotary transformer fault, provided in an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of limp control for a permanent magnet synchronous motor rotary transformer failure provided in an embodiment of this application.

[0019] Figure 3 This is a schematic diagram of position observation in the limp control method for a permanent magnet synchronous motor rotary transformer fault provided in the embodiments of this application.

[0020] Figure 4 This is a simulation diagram of limp mode switching in the prior art.

[0021] Figure 5 Simulation diagram of limp mode switching for the limp control method for a permanent magnet synchronous motor rotary transformer fault provided in the embodiments of this application.

[0022] Figure 6 A schematic diagram of the limp control device for a permanent magnet synchronous motor rotary transformer failure provided in this application embodiment. Detailed Implementation

[0023] This application provides a limp-off control method, device, and vehicle for a permanent magnet synchronous motor rotary transformer fault. By smoothly connecting the switching process through transition control, the current and voltage fluctuations caused by sudden angle changes are reduced, thereby improving the stability of motor control.

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the field of permanent magnet synchronous motor control, especially in applications involving electric vehicle drives or industrial servo systems, when a rotary transformer fails, it is necessary to achieve a non-stop switching from normal control mode to standby limp mode in order to maintain continuous system operation and ensure equipment safety and reliability.

[0026] In related technologies, to achieve the above objectives, a common approach is to switch to a limp-mode control based on high-frequency injection upon detecting a resolver fault. For example, a common practice is to directly switch, i.e., immediately converting the motor's control angle from the resolver's angle to the angle output by the high-frequency injection observer at the moment of fault detection. However, since the high-frequency injection observer requires a certain convergence time after startup, this direct switching method causes a jump in the control angle at the moment of switching, leading to drastic fluctuations in motor phase current and terminal voltage, posing a risk of overcurrent faults and affecting control stability. Furthermore, another approach, under low-speed conditions, requires the system to be stopped before re-entering limp-mode, which undoubtedly interrupts the operation and reduces system availability.

[0027] Therefore, in the technical environment of switching to high-frequency injection limp-mode after a resolver failure in a permanent magnet synchronous motor, how to avoid abrupt changes in control angle and the resulting current and voltage fluctuations caused by observer convergence delay, thereby ensuring a smooth and stable mode switching process, has become a specific technical problem that urgently needs to be solved. With the continuous improvement of requirements for the dynamic performance and operational continuity of motor control systems, the effective solution to the above problems is particularly urgent.

[0028] The technical solution of this application embodiment is applicable to the limp control application scenario when the rotary transformer of a permanent magnet synchronous motor fails. Figure 1 The diagram shown is a flowchart illustrating a limp-off control method for a permanent magnet synchronous motor rotary transformer fault according to an embodiment of this application, applied to a motor control unit connected to a motor controller. Figure 1 As shown, limp control for a permanent magnet synchronous motor rotary transformer fault includes: Step S11: When a rotary transformer fault is detected, record the first angle and first electrical angular velocity of the permanent magnet synchronous motor at the instant before the fault, and control it to enter limp mode.

[0029] After detecting a rotary transformer fault, the first angle and first electrical angular velocity of the permanent magnet synchronous motor before the fault are recorded. The initial angle and initial electrical angular velocity of the subsequently controlled permanent magnet synchronous motor can be obtained from the first angle and first electrical angular velocity to ensure the smooth operation of the vehicle.

[0030] Step S12: Based on the first angle, the first electrical angular velocity, and the real-time current of the permanent magnet synchronous motor, perform a transition phase control of the permanent magnet synchronous motor for a preset time, and obtain the second angle and the second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase.

[0031] The preset time can be set as needed and is not specifically limited here; preferably, it is set to 10ms. This preset time is the duration of the transition phase. Since the preset time is short, it can be approximated that the vehicle speed will not change. Therefore, the control electrical angular velocity of the permanent magnet synchronous motor during the transition phase can be the fixed electrical angular velocity before the fault. The angle of the permanent magnet synchronous motor can be obtained by integrating the first angle and the first electrical angular velocity before the fault. The permanent magnet synchronous motor is controlled for the preset time transition phase by real-time acquisition of the current of the permanent magnet synchronous motor. At the end of the transition phase, the second angle and the second electrical angular velocity of the permanent magnet synchronous motor are obtained. The second angle and the second electrical angular velocity are approximately equal to the angle and electrical angular velocity of the high-frequency injection method to ensure stable and continuous control during subsequent high-frequency voltage injection.

[0032] Step S13: Inject high-frequency voltage, and control the permanent magnet synchronous motor with the second angle and the second electric angular velocity as initial values ​​to achieve normal limp mode driving.

[0033] A high-frequency voltage is injected into the d-axis of the permanent magnet synchronous motor (PMSM). Using the second angle and second electrical angular velocity of the PMSM obtained at the end of the transition phase as initial values, high-frequency injection control is performed on the PMSM. Since the second angle and second electrical angular velocity are approximately equal to the angle and electrical angular velocity obtained through high-frequency injection, using these as initial values ​​for the PMSM's angle and electrical angular velocity avoids abrupt changes in angle and electrical angular velocity, effectively preventing angle jumps and the resulting current and voltage surges. This helps to quickly restore the PMSM's output torque response and enable normal limp-mode operation.

[0034] This embodiment of the application records the first angle and first electrical angular velocity of the permanent magnet synchronous motor (PMSM) at the instant before the fault is detected when a rotary transformer fault is detected, and controls it to enter limp mode. Based on the first angle, the first electrical angular velocity, and the real-time current of the PMSM, a preset-time transition phase control is performed on the PMSM. The second angle and second electrical angular velocity of the PMSM at the end of the transition phase are obtained. A high-frequency voltage is injected, and the PMSM is controlled using the second angle and the second electrical angular velocity as initial values ​​to achieve normal limp mode operation. A continuous transition phase is inserted in the time dimension, using the continuous state before the fault as the control signal source and observation starting point, thereby maintaining the continuity of the control angle and electrical angular velocity at the moment of switching. This effectively avoids angle jumps and the resulting current and voltage surges, achieving a smooth and uninterrupted switch from the pre-fault state to the stable state, ensuring stable operation of the entire vehicle.

[0035] In this embodiment, to ensure the continuity of the permanent magnet synchronous motor's angle and electrical angular velocity, a continuous transition phase is added after a rotary transformer failure. Based on this, the step of controlling the permanent magnet synchronous motor for a preset time transition phase according to the first angle, the first electrical angular velocity, and the real-time acquired current of the permanent magnet synchronous motor includes: integrating the first electrical angular velocity over time to obtain the transition control angle of the permanent magnet synchronous motor; using the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition phase, respectively, and combining the first angle and the real-time acquired current of the permanent magnet synchronous motor to perform transition phase control within a preset time. Specifically, the transition control angle of the permanent magnet synchronous motor is obtained by integrating the first electrical angular velocity over time. The transition control angle serves as the initial angle of the transition phase, and the first electrical angular velocity serves as the initial electrical angular velocity of the transition phase. After a preset control time, the angle and electrical angular velocity of the permanent magnet synchronous motor can be gradually changed to be equal to or close to the angle and electrical angular velocity of the high-frequency injection method. This helps to change the angle and electrical angular velocity of the permanent magnet synchronous motor from the state before the fault to the angle and electrical angular velocity of the high-frequency injection method through the transition phase, so as to ensure the continuity of the angle and electrical angular velocity and avoid angle jumps and the current and voltage surges they cause.

[0036] During the transition phase control, it is necessary to gradually transform the angle and electrical angular velocity of the permanent magnet synchronous motor from the pre-fault state to the angle and electrical angular velocity obtained by high-frequency injection. Based on this, optionally, the transition phase control is performed using the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition phase, respectively, combined with the first angle and the real-time acquired current of the permanent magnet synchronous motor, within a preset time. This includes: using the first electrical angular velocity as the initial electrical angular velocity of the transition phase, using the transition control angle as the initial angle of the transition phase, performing coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor according to the first angle within a preset time, and then outputting d-axis and q-axis voltages through a current loop in combination with the initial electrical angular velocity. Finally, after coordinate transformation and space vector pulse width modulation in combination with the initial angle, the permanent magnet synchronous motor is driven by an inverter. Within a preset time period, the current of the permanent magnet synchronous motor is collected in real time. Based on the first angle and the collected current, coordinate transformation is performed to obtain the d-axis and q-axis currents. The d-axis and q-axis current deviations are calculated based on the d-axis and q-axis currents at adjacent times. A preset current relationship table is consulted based on the initial electrical angular velocity and the required torque of the permanent magnet synchronous motor to obtain the required d-axis and q-axis currents. The required d-axis and q-axis currents are processed through a current loop to obtain the d-axis and q-axis voltages. Based on the d-axis and q-axis voltages and the estimated angle, coordinate transformation and space vector pulse width modulation are performed before the voltages are applied to drive the permanent magnet synchronous motor via an inverter. Through transition phase control, the angle and electrical angular velocity of the permanent magnet synchronous motor are transformed from the pre-fault state to the angle and electrical angular velocity obtained by high-frequency injection, ensuring the continuity of the angle and electrical angular velocity and effectively avoiding angle jumps and the resulting current and voltage surges.

[0037] After completing the transition phase control, a high-frequency voltage is injected for high-frequency injection control to restore the motor's output torque and enable limp-mode operation. Based on this, the injection of high-frequency voltage, using the second angle and the second electrical angular velocity as initial values ​​to control the permanent magnet synchronous motor and achieve normal limp-mode operation, includes: injecting high-frequency voltage into the d-axis of the permanent magnet synchronous motor using the second electrical angular velocity as the initial estimated electrical angular velocity and the second angle as the initial estimated angle; outputting d-axis and q-axis voltages through a current loop based on the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage; driving the permanent magnet synchronous motor through an inverter after coordinate transformation and space vector pulse width modulation based on the d-axis and q-axis voltages combined with the estimated angle; obtaining the d-axis current and q-axis current by performing coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor based on the estimated angle; and updating the estimated electrical angular velocity and the estimated angle using a position observer based on the q-axis current and the high-frequency voltage.

[0038] See Figure 2The estimated electric angular velocity is based on the second electric angular velocity as the initial value. The second angle is used as the initial estimated angle. Simultaneously, a high-frequency voltage is injected into the d-axis of the permanent magnet synchronous motor (IPMSM). Based on the estimated angle... The current of the permanent magnet synchronous motor is collected in real time. , The d-axis current is obtained after coordinate transformation. and q-axis current .in, The current of the A-axis of the permanent magnet synchronous motor (IPMSM) is collected. The B-axis current of the permanent magnet synchronous motor (IPMSM) is collected. Specifically, the current of the permanent magnet synchronous motor... , The α-axis current of the permanent magnet synchronous motor (IPMSM) is obtained after coordinate transformation by the first coordinate transformation module 11. and β-axis current According to the estimated angle With respect to α-axis current and β-axis current The d-axis current is obtained after coordinate transformation by the first coordinate transformation module 12. and q-axis current Then, based on the estimated electric angular velocity... The required torque of the permanent magnet synchronous motor The d-axis current, the q-axis current, and the high-frequency voltage are output as d-axis and q-axis voltages through a current loop. Specifically, based on the estimated electric angular velocity... The required torque of permanent magnet synchronous motors The d-axis current and q-axis current are applied to the current loop to output the d-axis and q-axis voltages. , Among them, the q-axis voltage output by the current loop This refers to the adjusted q-axis voltage and the d-axis voltage output by the current loop. High-frequency voltage injected with high frequency The adjusted d-axis voltage is obtained by superimposing the values. The angle is then estimated based on the adjusted d- and q-axis voltages. The α-axis voltage is obtained after coordinate transformation by the third coordinate transformation module. and β-axis voltage Space Vector Pulse Width Modulation (SVPWM) is used to control the α-axis voltage. and β-axis voltage After processing and calculation, six drive signals are generated, and the output drive voltage is transmitted to inverter 14. Inverter 14 receives the six drive signals, modulates the DC voltage to generate three-phase drive voltage, and transmits it to the permanent magnet synchronous motor (IPMSM). The angle error is determined based on the sign of the q-axis current and high-frequency voltage, and then the position observer is used to update the estimated electrical angular velocity and estimated angle. The control of the IPMSM is then performed according to the updated estimated electrical angular velocity and estimated angle for the next moment. This cycle is repeated to quickly restore the IPMSM's response output torque and enable limp-mode driving.

[0039] To accurately control the angle and electrical angular velocity using the high-frequency injection method, in this embodiment, updating the estimated electrical angular velocity and the estimated angle based on the q-axis current and the high-frequency voltage using a position observer includes: calculating half the difference between the q-axis currents at adjacent times to obtain the q-axis current deviation; determining the angle error based on the determined sign of the high-frequency voltage and the q-axis current deviation; performing position observation based on the angle error to obtain the updated estimated electrical angular velocity; and performing integration and polarity determination on the estimated electrical angular velocity to obtain the updated estimated angle. (Continue to see...) Figure 2 The q-axis current is obtained by coordinate transformation based on the real-time acquired current of the permanent magnet synchronous motor (IPMSM). The q-axis current deviation is obtained by calculating half the difference between the q-axis currents at adjacent time points. Specifically, the q-axis current at time t is calculated. q-axis current at time t-1 Half the difference, q-axis current deviation The sign of the determined high-frequency voltage. and q-axis current deviation Perform multiplication to obtain the angle error. Based on this angular error Position observations were conducted to obtain an updated estimated electric angular velocity. For estimating electric angular velocity After integration and polarity determination, an updated estimated angle can be obtained. This allows for accurate estimation of electrical angular velocity and angle, avoiding overcurrent caused by sudden angle changes in the control of the permanent magnet synchronous motor, and helping to restore the output torque of the permanent magnet synchronous motor for limp-mode operation.

[0040] After obtaining the angle error, a position observer in the phase-locked loop needs to be used for position observation to obtain an estimated electrical angular velocity. In the embodiment of the application, the step of observing the position based on the angle error to obtain an updated estimated electrical angular velocity includes: processing the angle error through a first amplifier and a second amplifier respectively; superimposing the output of the first amplifier with the initial electrical angular velocity or the angle at the previous moment, summing it with the output of the second amplifier, and then low-pass filtering to obtain the updated estimated electrical angular velocity. See also Figure 3 PT represents low-pass filtering, and 1 / Z represents a delay of one cycle. During the initial switching cycle of high-frequency injection, the first switching unit K1 selects the initial value of the angular velocity to be turned on, and the second switching unit K2 selects the initial value of the angle to be turned on. At this time, the angle error... After being amplified by a factor of Ki by the first amplifier, the result is superimposed on the initial value of the electrical angular velocity. Then, it is added to the angle error, which is amplified by a factor of Kp by the second amplifier. The result is then split into two outputs: one output is low-pass filtered to obtain the estimated electrical angular velocity, and the other output is added to the initial angle value to obtain the estimated angle. During the high-frequency injection control phase following the switching cycle, both the first switching unit K1 and the second switching unit K2 select to activate their corresponding delay units. At this time, the angle error... The result of amplifying the electrical angular velocity by a factor of Ki by the first amplifier is superimposed on the output of the first delay unit 15. This superimposed value is then added to the angle error amplified by a factor of Kp by the second amplifier, and the result is split into two outputs. One output is low-pass filtered to obtain an updated estimated electrical angular velocity, while the other output is added to the output of the first delay unit 15 to obtain an updated estimated angle. This allows for smooth control of the electrical angular velocity and angle of the high-frequency injection method, avoiding overcurrent caused by sudden angle changes in motor control.

[0041] In this embodiment, the step of integrating and determining the polarity of the estimated electrical angular velocity to obtain an updated estimated angle includes: performing time integration on the estimated electrical angular velocity to obtain the identification angle of high-frequency injection; determining the direct axis direction of the permanent magnet synchronous motor based on the d-axis current; and performing polarity synchronization processing on the identification angle based on the direction determination result to obtain the updated estimated angle. See also... Figure 2 For estimating electric angular velocity Time integration is performed to obtain the recognition angle for high-frequency injection. Further polarity determination is needed to obtain an accurate estimated angle. This can be done based on the d-axis current. The direct axis direction of the permanent magnet synchronous motor is determined, and then the polarity synchronization processing of the identified angle is performed based on the direction determination result to obtain an updated estimated angle. If based on the d-axis current... After polarity determination is completed, if the polarity is correct, the angle can be identified. Add zero to get the final estimated angle. If based on the d-axis current... After polarity determination is completed, if the polarities are opposite, the recognition angle is controlled. Add 180° to get the final estimated angle. By recognizing the angle After synchronously completing polarity determination and ensuring the current polarity is correct, the permanent magnet synchronous motor (IPMSM) resumes its output torque response and enters limp-mode driving.

[0042] In this embodiment, the step of outputting d-axis and q-axis voltages through a current loop based on the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage includes: calculating half of the sum of the q-axis currents at adjacent moments to obtain the q-axis correction current; calculating half of the sum of the d-axis currents at adjacent moments to obtain the d-axis correction current; looking up a preset current relationship table based on the estimated electrical angular velocity and the required torque of the permanent magnet synchronous motor to obtain the d-axis required current and the q-axis required current; calculating the difference between the d-axis required current and the d-axis correction current, and then applying proportional-integral control and superimposing the high-frequency voltage to obtain the d-axis voltage; calculating the difference between the q-axis required current and the q-axis correction current, and then applying proportional-integral control to obtain the q-axis voltage. (Continue to see...) Figure 2 The q-axis correction current is obtained by calculating half the sum of the q-axis currents at adjacent times t and t-1. , , Let be the q-axis currents at time t and t-1, respectively. Calculate half the sum of the d-axis currents at adjacent times t and t-1 to obtain the d-axis corrected current, i.e. , , These are the d-axis currents at time t and t-1, respectively. The estimated electric angular velocity is based on the current time. The required torque of permanent magnet synchronous motors The current demand along the d-axis at the current moment is obtained by searching the preset current relationship table MAP. and q-axis current demand Calculate the required current along the d-axis. The difference between the current and the d-axis correction current is then processed by proportional-integral control and superimposed with a high-frequency voltage. The d-axis voltage was then obtained. ; Calculate the required q-axis current The difference between the current and the q-axis correction current is used to obtain the q-axis voltage after proportional-integral control. Among them, high-frequency voltage It is a high-frequency square wave voltage.

[0043] The limp-off control method for permanent magnet synchronous motor rotary transformer faults in this application embodiment effectively avoids angle fluctuations by adding a transition phase, using a constant electrical angular velocity before the fault, and calculating the angle by integration. By transitioning the initial values ​​of the angle and electrical angular velocity after the high-frequency injection is turned on, current fluctuations or even overcurrent problems caused by sudden angle changes during the limp-off switching process can be effectively avoided.

[0044] The following is a comparison of simulation results of the limp-off control method for a permanent magnet synchronous motor rotary transformer fault according to embodiments of this application. Figure 4 and Figure 5 As shown, Figure 4 This is a simulation diagram of limp mode switching in the prior art, in which, Figure 4 'a' represents the angle error during a rotary transformer failure. Figure 4 b represents the changes in the corresponding RDC angle and HFI angle. Figure 4 c represents the change in RDC speed and HFI speed. Figure 5 This is a simulation diagram illustrating the limp mode switching of the method implemented in this application, wherein, Figure 5 'a' represents the angle error during a rotary transformer failure. Figure 5 b represents the changes in the corresponding RDC angle and HFI angle. Figure 5 c represents the changes in RDC and HFI rotation speeds. The RDC angle is the angular position measured or output by the rotary converter, the RDC rotation speed is the electrical angular velocity measured or output by the rotary converter, the HFI angle is the angle of high-frequency injection, and the HFI rotation speed is the electrical angular velocity of high-frequency injection. Figure 4 It can be seen that there is an angular error of 110° at the moment of switching, and the angle observation convergence is completed 0.02s after operation. Regarding the electrical angular velocity, it is identified from zero and only catches up with the actual electrical angular velocity after 0.02s. During this period, there are conditions with relatively large errors in angle and electrical angular velocity, which can easily cause vehicle vibration or even overcurrent faults. Figure 5 It can be seen that the angle error is zero at the moment of switching, and the angle convergence is completed in one operating cycle. Although the electric angular velocity has a period of 0.01s, it is controlled by the transition electric angular velocity during the period, so the transition of angle and electric angular velocity can be realized to ensure the stable operation of the whole vehicle.

[0045] The limp-walk control method for permanent magnet synchronous motor (PMSM) with rotary transformer fault in this application embodiment records the first angle and first electrical angular velocity of the PMSM at the instant before the fault is detected, and controls it to enter limp-walk mode. Based on the first angle, the first electrical angular velocity, and the real-time current of the PMSM, a preset-time transition phase control is performed on the PMSM. The second angle and second electrical angular velocity of the PMSM at the end of the transition phase are obtained. A high-frequency voltage is injected, and the PMSM is controlled using the second angle and the second electrical angular velocity as initial values ​​to achieve normal limp-walk mode operation. A continuous transition phase is inserted in the time dimension, using the continuous state before the fault as the control signal source and observation starting point, thereby maintaining the continuity of the control angle and electrical angular velocity at the moment of switching. This effectively avoids angle jumps and the resulting current and voltage surges, achieving a smooth and uninterrupted switch from the pre-fault state to the stable state, ensuring stable operation of the entire vehicle.

[0046] In one exemplary embodiment of this specification, a limp-off control device for a permanent magnet synchronous motor rotary transformer fault is also provided, applied to the motor control unit. For example... Figure 6 As shown, the limp-off control device 600 for a permanent magnet synchronous motor rotary transformer fault includes: The fault detection module 601 is used to record the first angle and first electrical angular velocity of the permanent magnet synchronous motor at the instant before the fault is detected when a rotary transformer fault is detected, and to control the motor to enter limp mode. The transition control module 602 is used to control the permanent magnet synchronous motor for a preset time transition phase based on the first angle, the first electrical angular velocity and the current of the permanent magnet synchronous motor collected in real time, and to obtain the second angle and the second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase. The injection control module 603 is used to inject high-frequency voltage and control the permanent magnet synchronous motor with the second angle and second electric angular velocity of the permanent magnet synchronous motor at the end of the transition phase as the initial value to achieve normal limp mode driving.

[0047] In some implementations, the transition control module 602 is used to: perform time integration based on the first electrical angular velocity to obtain the transition control angle of the permanent magnet synchronous motor; and use the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition stage, respectively, and combine the first angle and the real-time collected current of the permanent magnet synchronous motor to perform transition stage control within a preset time.

[0048] In some embodiments, the transition control module 602 is used to: take the first electrical angular velocity as the initial electrical angular velocity of the transition phase, take the transition control angle as the initial angle of the transition phase, and within a preset time, perform coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor according to the first angle, and output d-axis and q-axis voltages through the current loop in combination with the initial electrical angular velocity, and drive the permanent magnet synchronous motor through the inverter after coordinate transformation and space vector pulse width modulation in combination with the initial angle.

[0049] In some embodiments, the injection control module 603 is used to: inject a high-frequency voltage into the d-axis of the permanent magnet synchronous motor using the second electrical angular velocity as an initial estimated electrical angular velocity and the second angle as an initial estimated angle; perform coordinate transformation on the real-time acquired current of the permanent magnet synchronous motor according to the estimated angle to obtain the d-axis current and q-axis current; output the d-axis and q-axis voltages through a current loop according to the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage; drive the permanent magnet synchronous motor through an inverter after coordinate transformation and space vector pulse width modulation based on the d-axis and q-axis voltages combined with the estimated angle; and update the estimated electrical angular velocity and the estimated angle using a position observer based on the q-axis current and the high-frequency voltage.

[0050] In some embodiments, the injection control module 603 is further configured to: calculate half of the difference between the q-axis currents at adjacent times to obtain the q-axis current deviation; determine the angle error based on the determined sign of the high-frequency voltage and the q-axis current deviation; perform position observation based on the angle error to obtain an updated estimated electric angular velocity; and perform integration processing and polarity determination on the estimated electric angular velocity to obtain an updated estimated angle.

[0051] In some embodiments, the injection control module 603 is further configured to: process the angle error by a first amplifier and a second amplifier respectively; superimpose the output of the first amplifier with the initial electrical angular velocity or the angle at the previous moment, sum the sum with the output of the second amplifier, and obtain the updated estimated electrical angular velocity after low-pass filtering.

[0052] In some embodiments, the injection control module 603 is further configured to: perform time integration processing on the estimated electric angular velocity to obtain the identification angle of high-frequency injection; determine the direct axis direction of the permanent magnet synchronous motor based on the d-axis current; and perform polarity synchronization processing on the identification angle based on the direction determination result to obtain the updated estimated angle.

[0053] In some embodiments, the injection control module 603 is further configured to: calculate half of the sum of the q-axis currents at adjacent time points to obtain the q-axis correction current; calculate half of the sum of the d-axis currents at adjacent time points to obtain the d-axis correction current; look up a preset current relationship table based on the estimated electric angular velocity and the required torque of the permanent magnet synchronous motor to obtain the d-axis required current and the q-axis required current; calculate the difference between the d-axis required current and the d-axis correction current, and obtain the d-axis voltage after proportional-integral control and superposition of the high-frequency voltage; calculate the difference between the q-axis required current and the q-axis correction current, and obtain the q-axis voltage after proportional-integral control.

[0054] This application also provides a vehicle, including: the limp control device for the above-mentioned permanent magnet synchronous motor rotary transformer failure.

[0055] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0056] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0057] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0058] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0059] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0060] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A limp-off control method for a permanent magnet synchronous motor rotary transformer fault, characterized in that, The limp control method includes: When a rotary transformer fault is detected, the first angle and first electrical angular velocity of the permanent magnet synchronous motor at the instant before the fault are recorded, and the motor is controlled to enter limp mode. The permanent magnet synchronous motor is controlled for a preset time transition phase based on the first angle, the first electrical angular velocity, and the current of the permanent magnet synchronous motor collected in real time, and the second angle and the second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase are obtained. Injecting high-frequency voltage, and using the second angle and the second electrical angular velocity as initial values, the permanent magnet synchronous motor is controlled to achieve normal limp mode operation.

2. The method according to claim 1, characterized in that, The step of controlling the permanent magnet synchronous motor for a preset time transition phase based on the first angle, the first electrical angular velocity, and the real-time acquired current of the permanent magnet synchronous motor includes: The transition control angle of the permanent magnet synchronous motor is obtained by integrating the first electric angular velocity over time. The first electric angular velocity and the transition control angle are used as the initial electric angular velocity and initial angle of the transition stage, respectively. The transition stage control is performed within a preset time by combining the first angle and the current of the permanent magnet synchronous motor collected in real time.

3. The method according to claim 2, characterized in that, The transition phase control, which uses the first electrical angular velocity and the transition control angle as the initial electrical angular velocity and initial angle of the transition phase, respectively, and combines the first angle and the real-time acquired current of the permanent magnet synchronous motor for transition phase control within a preset time, includes: The first electrical angular velocity is used as the initial electrical angular velocity of the transition phase, and the transition control angle is used as the initial angle of the transition phase. Within a preset time period, the current of the permanent magnet synchronous motor, which is collected in real time, is transformed according to the first angle. Then, the d-axis and q-axis voltages are output through the current loop in combination with the initial electric angular velocity. After coordinate transformation and space vector pulse width modulation in combination with the initial angle, the permanent magnet synchronous motor is driven by the inverter.

4. The method according to claim 1, characterized in that, The injected high-frequency voltage, using the second angle and the second electrical angular velocity as initial values, controls the permanent magnet synchronous motor to achieve normal limp-mode operation, including: Using the second electrical angular velocity as the initial estimated electrical angular velocity and the second angle as the initial estimated angle, a high-frequency voltage is injected into the d-axis of the permanent magnet synchronous motor. Based on the estimated angle, the d-axis current and q-axis current are obtained by performing coordinate transformation on the real-time collected current of the permanent magnet synchronous motor. Based on the estimated electric angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage, the d-axis and q-axis voltages are output through a current loop. Based on the d-axis and q-axis voltages and the estimated angles, after coordinate transformation and space vector pulse width modulation, the permanent magnet synchronous motor is driven by an inverter. The estimated electric angular velocity and the estimated angle are updated based on the q-axis current and the high-frequency voltage using a position observer.

5. The method according to claim 4, characterized in that, The method of updating the estimated electric angular velocity and the estimated angle based on the q-axis current and the high-frequency voltage using a position observer includes: The q-axis current deviation is obtained by calculating half of the difference between the q-axis currents at adjacent time points. The angle error is determined based on the sign of the high-frequency voltage and the q-axis current deviation. The position is observed based on the angular error to obtain the updated estimated electric angular velocity; The estimated electric angular velocity is integrated and polarity is determined to obtain the updated estimated angle.

6. The method according to claim 5, characterized in that, The step of obtaining the updated estimated electric angular velocity by performing position observation based on the angular error includes: The angle error is processed by the first amplifier and the second amplifier respectively; The output of the first amplifier is superimposed with the initial electrical angular velocity or the angle at the previous moment, and then summed with the output of the second amplifier. After low-pass filtering, the updated estimated electrical angular velocity is obtained.

7. The method according to claim 5, characterized in that, The process of integrating the estimated electric angular velocity and determining its polarity to obtain the updated estimated angle includes: The estimated electric angular velocity is integrated over time to obtain the identification angle of the high-frequency injection. The direct axis direction of the permanent magnet synchronous motor is determined based on the d-axis current. Based on the direction determination result, the identified angle is subjected to polarity synchronization processing to obtain the updated estimated angle.

8. The method according to claim 4, characterized in that, The step of outputting d-axis and q-axis voltages through a current loop based on the estimated electrical angular velocity, the required torque of the permanent magnet synchronous motor, the d-axis current, the q-axis current, and the high-frequency voltage includes: The q-axis correction current is obtained by calculating half of the sum of the q-axis currents at adjacent time points; the d-axis correction current is obtained by calculating half of the sum of the d-axis currents at adjacent time points. Based on the estimated electric angular velocity and the required torque of the permanent magnet synchronous motor, a preset current relationship table is consulted to obtain the required current for the d-axis and the q-axis. The difference between the d-axis demand current and the d-axis correction current is calculated, and the d-axis voltage is obtained by applying proportional-integral control and superimposing the high-frequency voltage. The difference between the q-axis demand current and the q-axis correction current is calculated, and the q-axis voltage is obtained by applying proportional-integral control.

9. A limp-off control device for a permanent magnet synchronous motor rotary transformer fault, characterized in that, The device includes: The fault detection module is used to record the first angle and first electrical angular velocity of the permanent magnet synchronous motor just before the fault is detected when a rotary transformer fault is detected, and to control the motor to enter limp mode. The transition control module is used to control the permanent magnet synchronous motor for a preset time transition phase based on the first angle, the first electrical angular velocity, and the current of the permanent magnet synchronous motor collected in real time, and to obtain the second angle and the second electrical angular velocity of the permanent magnet synchronous motor at the end of the transition phase. An injection control module is used to inject high-frequency voltage and control the permanent magnet synchronous motor with the second angle and the second electrical angular velocity as initial values ​​to achieve normal limp mode operation.

10. A vehicle, characterized in that, The vehicle includes: a limp control device for a permanent magnet synchronous motor rotary transformer failure as described in claim 9.

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