A motor control method, a detection conversion device, a storage medium, and a controller

Abstract

This invention belongs to the field of power electronics technology, and particularly relates to a motor control method, detection and conversion device, storage medium and controller; the first current detection step / module obtains or the third fault diagnosis step / module selects the first current sensor sequence (700), and based on its first phase current (810), the second current reconstruction step / module combines the phase and amplitude information of the rotor position of the motor (999) and the first phase current (810) to construct the second observation value sequence (070) corresponding to the first given current sequence (054) of the motor (999) vector control, and uses it as a feedback signal to realize the closed-loop control of the motor (999); the method and product disclosed in this invention only require one current sensor to realize the detection and control process of at least two signals required by related technologies, effectively improving the reliability of the whole machine and the system robustness when some components fail, and is especially suitable for the vector control of permanent magnet synchronous motor (PMSM).

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, and particularly relates to a motor control method, a detection and conversion device, a storage medium, and a controller. Background Technology

[0002] In current closed-loop control, current detection is a necessary step. For example, in a permanent magnet synchronous motor (PMSM) control system, two or three current sensors are typically installed to acquire real-time phase current values, providing feedback information for completing the current closed-loop control. Since motor current is directly related to torque safety, current sensors require high diagnostic coverage. Therefore, regarding... Figure 2 Different failure modes of the current sensor shown will correspond to different diagnostic safety mechanisms.

[0003] like Figure 1 As shown, the related technology uses a first current sensor sequence (700) composed of dual current sensors (710, 720) to realize current closed-loop control. If a sensor is damaged or fails, it will cause the current signal of the control system to deviate, thereby affecting the reliability of the PMSM control system. At this time, the diagnostic system will report the current sensor fault and trigger the electric drive system to stop, so as to enter the safety protection state.

[0004] To improve system stability and efficiency and increase continuous operating time, it is necessary to ensure uninterrupted operation even when current sensors fail. Considering that it is extremely rare for all current sensors to fail simultaneously, using as few current sensors as possible to ensure control accuracy and operational stability has significant application value. In addition, there is a corresponding need for locating faulty sensors in order to quickly troubleshoot the fault or ensure that the system has a certain degree of redundancy. Summary of the Invention

[0005] This invention discloses a motor control method, the core of which includes a first current detection step and a second current reconstruction step. The first current detection step obtains a first current sequence corresponding to a first current sensor sequence. The first current sensor sequence includes at least a first current sensor, and the first current sequence includes at least a first phase current detected by the first current sensor. The second current reconstruction step reconstructs the first phase current. The reconstruction process uses a second observation value sequence corresponding to the first given current sequence of motor vector control as a feedback signal to realize closed-loop control of the motor. The second observation value sequence is determined by the first phase current based on the position of the corresponding motor rotor and the phase and amplitude of the first phase current.

[0006] The second current reconstruction step can obtain the first intermediate current in the two-phase stationary coordinate system from the first given current sequence through the first transformation process, and obtain the second intermediate current from the three-phase stationary coordinate system to the two-phase stationary coordinate system through the first phase current through the second transformation process; then, obtain the second observation value sequence from the two-phase stationary coordinate system to the rotating coordinate system through the first intermediate current and the second intermediate current through the third transformation process.

[0007] Specifically, the first intermediate current can be the β-axis current given value of the two-phase stationary coordinate system, i.e., i*β; the first given current sequence can be the dq given current vector of the rotating coordinate system; the dq given current vector includes the d-axis current given value i*d and the q-axis current given value i*q.

[0008] The reconstruction process obtains the rotor angle θ of the motor and the compensation angle x of the first phase current. The compensation angle is the electrical angle when the axis of phase α in the two-phase stationary coordinate system coincides with the first phase current. The first phase current is one phase in the three-phase stationary coordinate system.

[0009] Specifically, when the compensation angle x equals 0 degrees, the alignment of the first phase axis of the stator and the α phase axis of the motor is used as the vector control reference; when the compensation angle x equals 240 degrees, the alignment of the second phase axis of the stator and the α phase axis is used as the vector control reference.

[0010] In other scenarios, the first current sensor sequence may also include at least a second current sensor and / or a third current sensor; its first current sequence may also include at least the second phase current of the second current sensor and / or the third phase current of the third current sensor; and then the first phase current is replaced by the second phase current or the third phase current and the second current reconstruction step is used to achieve vector control of the motor.

[0011] For applications employing multiple current sensors, the motor control method may also include a third fault diagnosis step to respond to faults and switch the multi-sensor scenario to a single-sensor scenario. If the third fault diagnosis step has diagnosed a faulty current sensor or a faulty sensor sequence in the first current sensor sequence, then the current sensor in the faulty current sensor or faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection step and / or the second current reconstruction step.

[0012] Specifically, the current sensor with a fault or failure can be located by comparing the relationship table of the current sequence transformed from the first current sequence to the corresponding current sequence in the two-phase stationary coordinate system according to the preset failure mode data; the first phase and / or the second phase corresponding to the abnormal current value in the two-phase stationary coordinate system in the relationship table is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failed state.

[0013] If all current sensors in the first current sensor sequence are faulty or fail, vector control or motor operation is prohibited; the logic values ​​in the relation table are obtained by comparing the confidence intervals of the corresponding currents in the relation table based on the probability distribution corresponding to the failure mode data.

[0014] Specifically, the first transformation process can include the inverse Park transformation, the second transformation process can include the Clarke transformation, and the third transformation process can include the Park transformation.

[0015] Accordingly, this invention also discloses a detection and transformation device, the core components of which include a first current detection module and a second current reconstruction module; the first current detection module acquires a first current sequence corresponding to a first current sensor sequence; the first current sensor sequence includes at least a first current sensor, and the first current sequence includes at least a first phase current detected by the first current sensor; the second current reconstruction module reconstructs the first phase current; the reconstruction process uses a second observation value sequence corresponding to the first given current sequence of motor vector control as a feedback signal to realize closed-loop control of the motor; the second observation value sequence is determined by the first phase current based on the phase and amplitude of the motor rotor position and the first phase current.

[0016] The second current reconstruction module can obtain a first intermediate current in a two-phase stationary coordinate system from a first given current sequence through a first transformation process, and obtain a second intermediate current from a three-phase stationary coordinate system to a two-phase stationary coordinate system from the first phase current through a second transformation process; and obtain a second observation sequence from a two-phase stationary coordinate system to a rotating coordinate system from the first intermediate current and the second intermediate current through a third transformation process; the first intermediate current is the β-axis current given value i*β in the two-phase stationary coordinate system; the first given current sequence is the dq given current vector in the rotating coordinate system, including the d-axis current given value i*d and the q-axis current given value i*q.

[0017] Specifically, the reconfiguration process can obtain the rotor angle θ of the motor and the compensation angle x of the first phase current; the compensation angle x is the electrical angle when the α-phase axis of the two-phase stationary coordinate system coincides with the first phase current, and the first phase current is one phase in the three-phase stationary coordinate system; when the compensation angle x is equal to 0 degrees, the coincidence of the first phase axis of the stator and the α-phase axis is taken as the vector control reference; when the compensation angle x is equal to 240 degrees, the coincidence of the second phase axis of the stator and the α-phase axis is taken as the vector control reference.

[0018] The first current sensor sequence further includes at least a second current sensor and / or a third current sensor; the first current sequence further includes at least the second phase current of the second current sensor and / or the third phase current of the third current sensor; the first phase current is replaced by the second phase current or the third phase current and the motor is vector controlled by the second current reconstruction module.

[0019] Furthermore, the detection and conversion device may also be equipped with a third fault diagnosis module to adapt to a wider range of application scenarios; wherein, if the third fault diagnosis module has diagnosed that there is a faulty current sensor or a faulty sensor sequence in the first current sensor sequence, then the current sensor in the faulty current sensor or the faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection module and / or the second current reconstruction module.

[0020] Specifically, the system can locate faulty or failed current sensors by comparing the relationship table of the current sequence transformed from the first current sequence to the corresponding current sequence in the two-phase stationary coordinate system based on the preset failure mode data. In the relationship table, the first phase and / or the second phase corresponding to the abnormal current value in the two-phase stationary coordinate system is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failed state. If all current sensors in the first current sensor sequence are faulty or failed, vector control or motor operation is prohibited. The logical value in the relationship table can be obtained by comparing the confidence interval of the corresponding current in the relationship table according to the probability distribution corresponding to the failure mode data.

[0021] The first transformation process in the above-mentioned detection and transformation device may include a Park inverse transformation process, the second transformation process may include a Clarke transformation process, and the third transformation process may include a Park transformation process.

[0022] Similarly, embodiments of the present invention also disclose a computer storage medium and a controller; the computer storage medium includes a storage medium body for storing a computer program; when the computer program is executed by a microprocessor, it can implement any of the above motor control methods; the controller includes any of the above detection and conversion devices and / or computer storage media to address the same application scenarios and solve the same technical problems.

[0023] In summary, the first current detection step / module of this invention acquires or the third fault diagnosis step / module selects the first current sensor sequence, and based on its first phase current, the second current reconstruction step / module combines the phase and amplitude information of the motor rotor position and the first phase current to construct the second observation value sequence corresponding to the first given current sequence of motor vector control, and uses it as a feedback signal to realize the closed-loop control of the motor.

[0024] The method and product disclosed in this invention only require one current sensor to realize the detection and control process that requires at least two signals in related technologies, effectively improving the reliability of the whole machine and the system robustness in the event of failure of some components. It is especially suitable for vector control of permanent magnet synchronous motors (PMSM).

[0025] It should be noted that the terms "first," "second," and similar terms used in this article are merely for describing the constituent elements of the technical solution and do not constitute a limitation on the technical solution, nor should they be interpreted as an indication or implication of the importance of the corresponding elements; elements with terms such as "first," "second," or similar terms indicate that at least one of the elements is included in the corresponding technical solution. Attached Figure Description

[0026] To more clearly illustrate the technical solution of the present invention and facilitate a further understanding of its technical effects, features, and objectives, the present invention will be described in detail below with reference to the accompanying drawings. The drawings constitute an essential part of the specification and are used together with Embodiment 1 of the present invention to illustrate the technical solution of the present invention, but do not constitute a limitation on the present invention.

[0027] The same reference numerals in the attached diagram represent the same parts, as detailed below.

[0028] Figure 1 This is a schematic diagram of a current closed-loop control structure using a two-phase current sensor in related technologies.

[0029] Figure 2 Examples of six failure modes and their probability distributions for Hall current sensor chips are provided.

[0030] Figure 3 This is a block diagram illustrating the control principle of an embodiment of the present invention.

[0031] Figure 4 This is the Clarke transform expression.

[0032] Figure 5 This is a schematic diagram of a rotating coordinate system from the three phases UVW to the two phases αβ and then to the two phases dq.

[0033] Figure 6 This represents the static current vector and its Clarke transform with compensation angle.

[0034] Figure 7 This is the Clarke transformation matrix when the angle between the d-axis and the U-phase is 0 degrees.

[0035] Figure 8 This is one of the tables showing the relationship between UV phase current sensor faults and αβ two-phase currents.

[0036] Figure 9 This is the Clarke transformation matrix when the d-axis and the U-phase are at an angle of 240 degrees.

[0037] Figure 10 This is the second table showing the relationship between UV phase current sensor faults and αβ phase currents.

[0038] Figure 11 The given current vectors α and β are obtained by inverse Park transformation from the given d-axis and q-axis current values.

[0039] Figure 12 The β-axis current is given by the d-axis and q-axis current values, i.e., i*β.

[0040] Figure 13 This is a flowchart illustrating the process of obtaining the given current vectors α and β from the given d-axis and q-axis current values ​​and the angle θ+x.

[0041] Figure 14 This is a schematic diagram of the fault detection process according to an embodiment of the present invention.

[0042] Figure 15 This is a schematic diagram illustrating the process of transitioning from a three-phase stationary coordinate system to a two-phase stationary coordinate system according to an embodiment of the present invention.

[0043] Figure 16 In this embodiment of the invention, the given current vectors α and β in the two-phase stationary coordinate system are transformed into the observed currents along the d and q axes in the rotating coordinate system.

[0044] Figure 17 This is an embodiment of the invention showing the d-axis and q-axis current waveforms when the V-phase current sensor fails and a U-phase single current sensor is selected for electric drive system control.

[0045] Figure 18 The above describes the α and β phase shaft current waveforms in an embodiment of the present invention when the V-phase current sensor fails and a U-phase single current sensor is selected for electric drive system control.

[0046] Figure 19 This embodiment of the invention provides the motor speed, motor torque, and actual three-phase current waveforms of the motor when the V-phase current sensor fails and a U-phase single current sensor is selected for electric drive system control.

[0047] Figure 20 The d-axis and q-axis current waveforms are shown in the embodiment of the present invention when the only normal single current sensor electric drive system is controlled.

[0048] Figure 21 The waveforms of the α and β phase shaft currents are shown in the embodiment of the present invention when the only normal single current sensor electric drive system is controlled.

[0049] Figure 22The figures represent the motor speed, motor torque, and actual three-phase current waveforms of the motor when controlled by the only remaining normal single-current sensor electric drive system according to an embodiment of the present invention.

[0050] Figure 23 This is a schematic diagram of the process of an embodiment of the method of the present invention.

[0051] Figure 24 This is a schematic diagram of the structural composition of an embodiment of the device of the present invention.

[0052] Figure 25 This is a schematic diagram of the layout structure of an embodiment of the product of the present invention. Figure 1 .

[0053] Figure 26 This is a schematic diagram of the layout structure of an embodiment of the product of the present invention. Figure 2 .

[0054] in: 010-Fault diagnosis structure / module; 011-Battery / Battery Management System; 013 - Inverter; 015 - Three-phase AC motor; 016 - Position sensor, also known as PS (Position Sensor). 019 - Spindle; 020-αβ static current vector; 021-α static current, i.e., iα; 022-β static current, i.e., iβ; The actual current value collected for phase 031-U, i.e., iu; The actual current value collected for phase 032-V (not shown in the figure), i.e., iv; The actual current value collected for phase 033-W, i.e., iw; 040-Clarke transformation (matrix); Phase angle relationship (Clarke transform) when the angle between the 041-d axis and the U phase is 0 degrees; Phase angle relationship when the 042-d axis and the U phase are at an angle of 240 degrees (Clarke transform); Phase angle relationship when the 043-d axis and the U phase are at an angle of 120 degrees (Clarke transform); 050 - Second group of given currents, such as αβ given current vector; 051-α axis current setpoint, i.e., i*α; 052-β axis current setpoint, i.e., i*β; 054 - First given current sequence, such as dq given current vector; 055-d axis current setpoint, i.e., i*d; 057 - q-axis current setpoint, i.e., i*q; 061- Park inverse transform (matrix); 070 - Second observation sequence; 088 - compensation angle, i.e., x; 099 - Rotor angle, i.e. θ (which can be obtained from the position sensor PS). 100 - First current detection step; 113 - First intermediate current (between the first conversion module and the third conversion module); 153 - Second intermediate current (between the fifth and third conversion modules); 200 - Second current reconfiguration step; 210 - First Transformation Process 210; 220 - Second transformation process 220; 230 - Third Transformation Process 230; 300 - Third fault diagnosis step; 330 - Relationship Table (not shown in the attached diagram); 331 - First Relationship Table (used to detect faults in the first current sensor or abnormalities in the first phase current); 332 - Second Relationship Table (used to detect faults in the second current sensor or abnormalities in the second phase current); 333 - Third Relationship Table (used to detect faults in the third current sensor or abnormalities in the third phase current) (not shown in the attached diagram); 388 - (Failure Mode) Probability Distribution; 399 - Failure Mode; 600 - Detection and conversion device; 601-First Transformation Module (transforms the given current dq into a given current αβ in a two-phase stationary coordinate system according to the angle θ+x); 603 - Third Transformation Module (transforms the given current in the two-phase stationary coordinate system αβ into the observed current in the rotating coordinate system); 605 - Fifth Transformation Module (Signal Selection from Three-Phase Stationary Coordinate System to Two-Phase Stationary Coordinate System); 607 - Seventh Selection Module (for fault detection and current selection); 610 - First Current Detection Module; 620 - Second Current Reconfiguration Module; 630 - Third Fault Diagnosis Module; 700 - First current sensor sequence; 710 - First Current Sensor; 720 - Second Current Sensor; 730 - Third current sensor (not shown in the attached diagram); 800 - First current sequence (not shown in the attached diagram); 810 - First phase current, such as iu; 820 - Second phase current, such as IV; 830 - Third phase current, such as iw (not shown in the attached diagram); 900-Vehicles, such as electric or hybrid vehicles; 901 - Controllers, such as Electronic Control Units (ECUs); 903 - Computer storage media, such as digital signal processing (DSP) chips, intelligent power modules (IPMs) or power integrated circuits (PICs). 999 - Motors, such as permanent magnet synchronous motors (PMSM). Detailed Implementation

[0055] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described below are merely illustrative of the technical solutions of the present invention, and not intended to limit the invention. Furthermore, the parts described in the embodiments or drawings are merely illustrative examples of relevant parts of the present invention, and not the entirety of the invention.

[0056] like Figure 23 The motor control method and core steps shown include a first current detection step 100 and a second current reconstruction step 200; the first current detection step 100 is as follows: Figure 1 As shown, a first current sequence 800 corresponding to a first current sensor sequence 700 is obtained; the first current sensor sequence 700 includes at least a first current sensor 710, and the first current sequence 800 includes at least a first phase current 810 detected by the first current sensor 710.

[0057] Furthermore, the second current reconstruction step 200 reconstructs the first phase current 810; as follows: Figure 3 As shown, the reconstruction process uses the second observation sequence 070 corresponding to the first given current sequence 054 of the motor 999 vector control as the feedback signal to realize the closed-loop control of the motor 999; the second observation sequence 070 is determined by the first phase current 810 based on the rotor position of the motor 999 and the phase and amplitude of the first phase current 810.

[0058] Among them, such as Figure 3 , 13As shown in Figure 15, the second current reconstruction step 200 obtains the first intermediate current 113 in the two-phase stationary coordinate system from the first given current sequence 054 through the first transformation process 210, and obtains the second intermediate current 153 from the three-phase stationary coordinate system to the two-phase stationary coordinate system from the first phase current 810 through the second transformation process 220; and obtains the second observation value sequence 070 from the two-phase stationary coordinate system to the rotating coordinate system from the first intermediate current 113 and the second intermediate current 153 through the third transformation process 230.

[0059] Specifically, such as Figure 3 , 11 As shown, the first intermediate current 113 is the β-axis current given value 052 of the two-phase stationary coordinate system, i.e., i*β; the first given current sequence 054 is the dq given current vector of the rotating coordinate system, including the d-axis current given value 055, i.e., i*d and the q-axis current given value 057, i.e., i*q.

[0060] Furthermore, such as Figure 3 As shown, the reconstruction process can obtain the rotor angle θ of motor 999 and the compensation angle x of the first phase current 810; as Figure 5 As shown, the compensation angle 088 is the electrical angle when the axis of phase α in the two-phase stationary coordinate system coincides with the first phase current 810, and the first phase current 810 is one phase in the three-phase stationary coordinate system.

[0061] Specifically, when the compensation angle x equals 0 degrees, the alignment of the first phase axis of the stator of motor 999 with the α phase axis is used as the vector control reference; when the compensation angle x equals 240 degrees, the alignment of the second phase axis of the stator with the α phase axis is used as the vector control reference.

[0062] Furthermore, such as Figure 3 As shown, the embodiments of the present invention are also applicable to scenarios where the first current sensor sequence 700 further includes a second current sensor 720 and / or a third current sensor 730; the first current sequence 800 further includes at least the second phase current 820 of the second current sensor 720 and / or the third phase current 830 of the third current sensor 730; the first phase current 810 is replaced by the second phase current 820 or the third phase current 830 and vector control is achieved for the motor 999 using the second current reconstruction step 200.

[0063] In addition, such as Figure 23As shown, this embodiment of the invention also includes a third fault diagnosis step 300; if the third fault diagnosis step 300 has diagnosed that the first current sensor sequence 700 has a faulty current sensor or a faulty sensor sequence, then the current sensor in the faulty current sensor or the faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection step 100 and / or the second current reconstruction step 200.

[0064] Among them, such as Figure 2 , 8 As shown in Figure 10, the failure mode data 399 compares the current sequence transformed from the first current sequence 800 to the corresponding current sequence in the two-phase stationary coordinate system in the relationship table 330 to locate the current sensor that has a fault or failure; in the relationship table 330, the first phase and / or the second phase corresponding to the abnormal current value in the two-phase stationary coordinate system is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failed state.

[0065] Specifically, such as Figure 8 , 10 If all current sensors in the first current sensor sequence 700 are faulty or fail, then vector control or motor 999 operation is prohibited; the logic value in relation table 330 is obtained by comparing the confidence interval of the current corresponding to relation table 330 according to the probability distribution 388 corresponding to failure mode data 399.

[0066] Among them, such as Figure 4 , 6 As shown in 7, 9, 11 to 16, the first transformation process 210 may include the process of using the inverse Park transformation 061, the second transformation process 220 may include the process of using the Clarke transformation 040, and the third transformation process 230 may include the process of using the Park transformation.

[0067] Accordingly, such as Figure 24 The core components of the detection and conversion device 600 shown include a first current detection module 610 and a second current reconstruction module 620. The first current detection module 610 acquires a first current sequence 800 corresponding to a first current sensor sequence 700. The first current sensor sequence 700 includes at least a first current sensor 710, and the first current sequence 800 includes at least a first phase current 810 detected by the first current sensor 710. The second current reconstruction module 620 reconstructs the first phase current 810. The reconstruction process uses the second observation value sequence 070 corresponding to the first given current sequence 054 of the motor 999 vector control as a feedback signal to realize the closed-loop control of the motor 999. The second observation value sequence 070 is determined by the first phase current 810 based on the rotor position of the motor 999 and the phase and amplitude of the first phase current 810.

[0068] Among them, such as Figure 3 , 13 As shown in Figure 15, the second current reconstruction module 620 obtains the first intermediate current 113 of the two-phase stationary coordinate system from the first given current sequence 054 through the first transformation process 210, and obtains the second intermediate current 153 from the three-phase stationary coordinate system to the two-phase stationary coordinate system from the first phase current 810 through the second transformation process 220; and obtains the second observation value sequence 070 from the two-phase stationary coordinate system to the rotating coordinate system from the first intermediate current 113 and the second intermediate current 153 through the third transformation process 230; the first intermediate current 113 is the β-axis current given value 052 of the two-phase stationary coordinate system, i.e., i*β; the first given current sequence 054 is the dq given current vector of the rotating coordinate system, including the d-axis current given value 055, i.e., i*d, and the q-axis current given value 057, i.e., i*q.

[0069] Further, the reconstruction process obtains the rotor angle θ of motor 999 and the compensation angle x of the first phase current 810. The compensation angle x is the electrical angle when the axis of the α phase in the two-phase stationary coordinate system coincides with the first phase current 810, and the first phase current 810 is one phase in the three-phase stationary coordinate system. When the compensation angle x is equal to 0 degrees, the coincidence of the first phase axis of the stator of motor 999 with the α phase axis is used as the vector control reference. When the compensation angle x is equal to 240 degrees, the coincidence of the second phase axis of the stator with the α phase axis is used as the vector control reference.

[0070] The first current sensor sequence 700 further includes at least a second current sensor 720 and / or a third current sensor 730; the first current sequence 800 further includes at least a second phase current 820 of the second current sensor 720 and / or a third phase current 830 of the third current sensor 730; the first phase current 810 is replaced by the second phase current 820 or the third phase current 830 and the second current reconstruction module 620 is used to implement vector control of the motor 999.

[0071] Furthermore, such as Figure 24 As shown, the detection and conversion device 600 is also provided with a third fault diagnosis module 630; if the third fault diagnosis module 630 has diagnosed that there is a faulty current sensor or a faulty sensor sequence in the first current sensor sequence 700, then the current sensor in the faulty current sensor or the faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection module 610 and / or the second current reconstruction module 620.

[0072] Among them, such as Figure 2As shown, the relationship table 330, which is the current sequence corresponding to the first current sequence 800 transformed into the two-phase stationary coordinate system, is compared with the preset failure mode data 399 to locate the current sensor that has a fault or failure. The first phase and / or the second phase corresponding to the abnormal current value in the two-phase stationary coordinate system in the relationship table 330 is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failed state. If all the current sensors in the first current sensor sequence 700 have faults or failures, then vector control or the motor 999 is prohibited from running. The logical value in the relationship table 330 is obtained by comparing the confidence interval of the current corresponding to the relationship table 330 according to the probability distribution 388 corresponding to the failure mode data 399.

[0073] Specifically, the first transformation process 210 adopts the Park inverse transformation 061 process, the second transformation process 220 adopts the Clarke transformation 040 process, and the third transformation process 230 adopts the Park transformation process.

[0074] Similarly, such as Figure 25 , 25 The computer storage medium 903 and controller 901 shown adopt the same technical concept; the computer storage medium 903 includes a storage medium body for storing computer programs; when the computer program is executed by the microprocessor, it can implement any of the above motor control methods; the controller 901 includes any of the above detection and conversion devices 600 and / or computer storage medium 903.

[0075] In practical applications, this invention discloses a control scheme for a motor drive system based on a single current sensor; its core lies in the implementation process or corresponding product of the current observer, i.e., the detection and conversion device 600.

[0076] Specifically, such as Figure 2 The embodiment shown is for an automotive electric drive control system employing a two-phase current sensor, specifically a system including a first current sensor 710 and a second current sensor 720; wherein the automotive electric drive control system employs as follows Figure 3 The system structure shown uses a three-phase permanent magnet synchronous motor (PMSM) as the actuator. When a current sensor in one phase fails, this embodiment of the invention can shield the current sensor with abnormal operating status and make up for the lack of current information. This allows the missing signal to be reconstructed based on the remaining measurement information even after some current sensors fail, ensuring that the motor 999 can still work normally with the help of the only valid current sensor when there is a problem in the signal acquisition stage.

[0077] It should be noted that in the case of all sensors failing, due to the lack of necessary reference data, the present invention also adopts the method of stopping the system to protect its safety. However, since the probability of all current sensors failing is relatively small, the present invention can still ensure the normal output of motor 999 in most operating segments, thus greatly improving the safety and robustness of the system.

[0078] Specifically, such as Figure 3 As shown, the detection and transformation device 600 disclosed in this embodiment of the invention adopts a current observer of the electric drive system based on a single current sensor as its core; and integrates the electric drive system fault detection and the current observation and current feedback value reconstruction process of the rotating coordinate system dq axis.

[0079] Among them, the motor 099 of the execution unit adopts an improved permanent magnet synchronous motor; the detection and conversion device 600 consists of a first conversion module 601, a third conversion module 603, a fifth conversion module 605, and a seventh selection module 607.

[0080] Specifically, the first transformation module 601 can transform the given current dq into the given current αβ in the two-phase stationary coordinate system according to the angle θ+x; the third transformation module 603 can transform the given current αβ in the two-phase stationary coordinate system into the observed current in the rotating coordinate system, that is, into the feedback current vector required for vector control; the fifth transformation module 605 is used to realize the transformation of the three-phase stationary coordinate system data into the two-phase stationary coordinate system data; and the seventh selection module 607 can select the current signal according to the conclusion of the fault diagnosis.

[0081] The first given current sequence 054, i.e., the given current vector dq, comes from the maximum torque per ammeter (MTPA) module of the permanent magnet synchronous motor operating in the base speed region. This module can distribute torque commands (such as speed limits) to obtain the given current vector dq. Simultaneously, the position sensor PS acquires the rotor angle θ of the motor 999 and combines it with the compensation angle 088, i.e., x, output by the seventh selection module 607 for coordinate transformation. The seventh selection module 607 performs fault detection and current selection, first identifying the failed current sensor, and then sending the remaining U-phase or V-phase current to the fifth transformation module 605.

[0082] Furthermore, the fifth transformation module 605 transforms the data from the three-phase stationary coordinate system to the two-phase stationary coordinate system and outputs the α static current, i.e., iα, which is the second intermediate current 153.

[0083] On the other hand, the first conversion module 601 converts the given current vector dq and angle θ+x output by the MTPA module into an αβ static current vector and outputs a β static current iβ, which is the first intermediate current i13. It should be noted that the reconstruction of the β static current iβ is not related to the fault of a specific phase current sensor.

[0084] Furthermore, the first intermediate current 113 and the second intermediate current 153 are sent to the third transformation module 603, which can then convert the current αβ in the two-phase stationary coordinate system into the dq observation current in the rotating coordinate system, i.e., the second observation value sequence 070; and finally, the second observation value sequence 070 is sent into the current closed loop to realize the vector control of motor 999.

[0085] Specifically, taking the PMSM vector control with dual current sensors as an example, the first conversion process 210, the second conversion process 220, and the third conversion process 230 are explained as follows.

[0086] Among them, the transformation from the three-phase stationary coordinate system to the two-phase stationary coordinate system of the permanent magnet synchronous motor (PMSM) is the Clarke transformation, which is the second transformation process 220 implemented by the fifth transformation module.

[0087] Specifically, when the U phase of the three-phase stationary coordinate system is set to coincide with the α axis of the αβ stationary coordinate system, the following is obtained: Figure 4 The Clarke transform process is shown.

[0088] Furthermore, such as Figure 3 As shown, data transformation can be performed from the three-phase UVW to the two-phase αβ coordinate system and then to the two-phase rotating coordinate system dq. In this embodiment, the PMSM vector control system uses two current sensors. These two current sensors can be installed on any two phases, and their installation combination can be U+V, V+W, or U+W. In this embodiment, they are installed on the U and V phases.

[0089] Specifically, such as Figure 5 As shown in section 041, during the Clark transformation (i.e., 3s / 2s), it is assumed that the stator U-phase axis coincides with the transformed α-phase axis; at this time, the angle between the rotation d-axis and the U-phase is θ; as... Figure 5 As shown in reference numeral 042, it is assumed that the stator V-phase axis coincides with the transformed α-phase axis, and the angle between its rotation d-axis and the U-phase is θ+240 degrees; furthermore, as Figure 5 As shown in reference number 043, assuming that the stator W-phase axis coincides with the transformed α-phase axis, the angle between the rotation d-axis and the V-phase is θ+120°.

[0090] Specifically, the compensation angle 088 can be defined as the array x=[0, 240, 120]; according to Kirchhoff's current law, the sum of the three-phase currents of the motor, iu+iv+iw, is zero; thus, iw, i.e., the third-phase current, is 830; as Figure 6 As shown, the UV phase coordinate system can be transformed to the αβ phase coordinate system, where Ax is the Clarke transformation matrix.

[0091] Considering that only two current sensors are used, the third phase array does not need to be listed in detail; and when the stator U-phase axis coincides with the transformed α-phase axis, the angle between its rotation d-axis and the U-phase is θ, x=0 degrees, then the following can be obtained: Figure 7 The Clarke transformation matrix is ​​shown.

[0092] At this time, if the U-phase current sensor, i.e. the first current sensor 710, malfunctions, the values ​​of its α and β phase currents will be abnormal; while when the V-phase current sensor, i.e. the second current sensor 720, malfunctions, the value of the α phase current is normal, the α phase current is equal to the U-phase current, and only the value of the β phase current is abnormal.

[0093] Specifically, it can be constructed as follows Figure 8 The first relationship table 331 is shown; its dashed boxes correspond to reliable values, while the parts marked with an × indicate that the corresponding phase current sensor has failed or malfunctioned.

[0094] When the stator V-phase axis coincides with the transformed α-phase axis, and the angle between the rotation d-axis and the U-phase is θ+240 degrees (i.e., x is 240 degrees), then the following is obtained: Figure 9 The Clarke transformation matrix is ​​shown.

[0095] Specifically, when the U-phase current sensor malfunctions, the α-phase current value is normal and equal to the V-phase current, while only the β-phase current value is abnormal; conversely, when the V-phase current sensor malfunctions, both the α-phase and β-phase current values ​​are abnormal; based on this, we can obtain the following... Figure 10 The relationship table 332 shown also has dashed boxes corresponding to reliable values, while the parts marked with an × indicate that the corresponding phase current sensor has failed or malfunctioned.

[0096] It should be noted that when both the U-phase and V-phase current sensors fail simultaneously, the necessary reference information is missing, and the electric drive system needs to be shut down; at the same time, the corresponding load, such as vehicle 900, will be unable to continue operating.

[0097] The first conversion module converts the given current dq and angle θ+x output by the MTPA module into the given current αβ; while the angle θ+x comes from the motor rotor angle collected by the position sensor PS and the compensation angle x output by the seventh selection module 607.

[0098] Specifically, it can be based on, for example Figure 11 The process shown yields the second set of given currents 050, which is the αβ given current vector; that is, the given current value in the αβ phase coordinate system is obtained by inverse Park transformation 061 after the dq given value allocated by the electric drive control system MTPA from the table.

[0099] Similarly, a given β current can be output, and the reconstruction of the β-axis current is independent of the fault in the phase current sensor to be diagnosed, thus allowing for the calculation based on... Figure 12 The process shown is as follows.

[0100] Where θ is the angle between the d-axis of the synchronous rotating coordinate system and the U-phase axis; x is the electrical angle when the α-phase axis coincides with the U-phase, V-phase, and W-phase respectively; similarly, x can be made equal to [0, 240, 120] degrees, while i*d and i*q are the dq-axis current setpoints output by the MTPA module; specifically, it can be determined according to... Figure 13 The information flow shown undergoes the first transformation process 210.

[0101] Furthermore, fault diagnosis processes or modules can be added to increase the system's applicability; by adding, for example... Figure 3 and Figure 14 The seventh selection module 67 shown realizes fault detection and current selection; firstly, it screens out the phase with a faulty current sensor, and then filters the collected signals.

[0102] Specifically, the fault-free or undamaged U-phase or V-phase current is fed into the fifth transformation module 605, and the compensation angle is also input for coordinate transformation.

[0103] like Figure 2 As shown, six failure modes 399 and their corresponding probability distributions 388 are given. If this embodiment is adopted, the control process is based on a single current sensor, which requires fault diagnosis of the current sensor as a prerequisite. Therefore, the following process is also required for fault screening.

[0104] One is "Phase current sampling circuit fault" SM1; specifically, if the sensor output is short-circuited to the power supply, short-circuited to ground, or open-circuited, it is a circuit fault; considering that the internal hardware circuit of the motor controller will pull down the resistors at the input and output of the current sampling channel, i.e., the I / O port, when the current sensor chip has a fixed maximum or minimum current sampling value, it can be determined that it is a short circuit failure or an open circuit failure, and thus report a phase current sampling circuit fault.

[0105] The second is "Phase current sampling range fault" SM2; specifically, if the sensor output signal exceeds the specified range, it is considered that there is a phase current sampling range failure problem; a reference threshold can be set according to the calibration data, and when the output signal is greater than the reference threshold, a phase current sampling range fault can be reported.

[0106] The third is "motor phase current sensor stuck fault" SM3; when any phase current is stuck at a specific current value, stuck at a small current value, or stuck at any value, it can be determined by monitoring the waveform changes of each phase current in real time; if the phase current waveform does not cross the zero point in each electrical cycle, then it is considered that a stuck fault has occurred.

[0107] The fourth is "Phase Current Bias Diagnosis" SM4; during the operation of the electric drive system, the microcontroller unit (MCU) calculates the phase current amplitude in real time for each electrical cycle. The bias calculation is to collect the maximum value Imax and minimum value Imin of the phase current sine wave. The bias value Ioffs = (Imax + Imin) / 2. The theoretical current bias value of each phase of the motor is 0; however, when the bias value is greater than a certain threshold, it can be considered that there is a phase current bias fault in the electric drive system.

[0108] The fifth is the "three-phase current sum is not zero fault" SM5; using Kirchhoff's law Iu+Iv+Iw=0, that is, the total current flowing into the node is equal to the total current flowing out of the node, when any one phase current sensor is abnormal, its three-phase current sum is not zero; based on this, the abnormal phenomenon of the current sensor can be diagnosed; if the three-phase current sum value exceeds the set threshold, it can be considered that there is a fault in the three-phase current sum of the electric drive system.

[0109] Its six-digit "Motor Phase Current Amplitude Fault" SM6; similarly, during the operation of the electric drive system, the microcontroller unit (MCU) calculates the phase current amplitude in real time for each electrical cycle; specifically, the amplitude Iamp = (Imax - Imin) / 2 can be obtained based on the maximum and minimum values ​​of the phase current sine wave Imax and Imin; considering that the current amplitude between the phases of the motor is theoretically equal, when the current amplitude of one phase increases or decreases, the phase current amplitude fault can be diagnosed by comparing the amplitude between the phases; if the amplitude deviation between the phases exceeds the threshold, the electric drive system is considered to have an amplitude reasonableness diagnostic fault.

[0110] In summary, fault diagnosis can be performed in the third fault diagnosis step 300 to screen out the location of the fault; among them, the diagnostic safety mechanisms SM1, SM2, SM3 and SM4 can accurately screen out specific current sensors.

[0111] Specifically, if a current sensor fails, it can be quickly isolated or removed; and the closed-loop feedback signal can be reconstructed through the first current detection step 100 and the second current reconstruction step 200.

[0112] Specifically, when the U-phase current sensor fails, the seventh selection module 607 will use the V-phase current and x=240 degrees as output signals to participate in the processing of the next module; when the V-phase current sensor fails, the seventh selection module 607 will use the U-phase current and x=0 degrees as output signals to participate in the processing of the next module; wherein, the seventh selection module 607 can refer to Figure 14 The structure is used to select signals.

[0113] The fifth transformation module 605 performs signal processing from a three-phase stationary coordinate system to a two-phase stationary coordinate system; it takes the U-phase or V-phase current from the seventh selection module 607 and the compensation angle 088 (x) used for the coordinate transformation algorithm as input information, and performs data processing in combination with two preconditions.

[0114] Specifically, such as Figure 15 As shown, when x is 0 degrees, the vector control reference is the coincidence of the stator U-phase axis and the transformed α-phase axis; when x is 240 degrees, the vector control reference is the coincidence of the stator V-phase axis and the transformed α-phase axis.

[0115] Furthermore, such as Figure 3 As shown, the third transformation module 603 converts the current αβ in the two-phase stationary coordinate system into the observed currents i^d and i^q in the rotating coordinate system, thus obtaining the second observation sequence 070.

[0116] Among them, such as Figure 16 As shown, the rotor angle θ of motor 999 from position sensor PS and the compensation angle x output by seventh selection module 607 also need to be used for coordinate transformation; the α-phase current from fifth transformation module 605 and the β-phase given current from first transformation module 601 are sent together to three transformation module 603; internally, the currents α and β in the two-phase stationary coordinate system are converted into dq observation currents in the rotating coordinate system, namely the aforementioned d-axis observation current i^d and q-axis observation current i^q; then the complete current feedback can be sent to the system integration unit to realize closed-loop control of motor 999.

[0117] It should be noted that the application scenario of this embodiment is for vehicle electric drive control systems that use two-phase current sensors. When a certain phase current sensor fails, based on the above processing, the failure information of the current sensor with abnormal working state can be reconstructed to make up for the missing information. Thus, even if some sensors fail, the control system can still be ensured to operate and the same performance indicators can still be ensured by relying on the remaining detection information.

[0118] Based on this, in this embodiment, in a system with a dual current sensor structure, when one sensor malfunctions or fails, a single current sensor is used to achieve the operation control of the electric drive system, thus enabling... Figure 25The vehicle 900 shown was able to continue operating, avoiding losses caused by stopping; at the same time, since the failure of all sensors is a low-probability event, the original current sensor signals have information redundancy, thereby improving the safety and robustness of the electric drive system using current closed loop.

[0119] It should be noted that the above embodiments are only for more clearly illustrating the technical solution of the present invention. Those skilled in the art will understand that the implementation of the present invention is not limited to the above content. Any obvious changes, substitutions or replacements made based on the above content do not exceed the scope of the technical solution of the present invention. Other implementations will also fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A motor control method, characterized in that... The process includes a first current detection step (100) and a second current reconstruction step (200). The first current detection step (100) acquires a first current sequence (800) corresponding to a first current sensor sequence (700). The first current sensor sequence (700) includes at least a first current sensor (710), and the first current sequence (800) includes at least a first phase current (810) detected by the first current sensor (710). The second current reconstruction step (200) reconstructs the first phase current (810). The reconstruction process uses a second observation value sequence (070) corresponding to the first given current sequence (054) of the motor (999) vector control as a feedback signal to realize the closed-loop control of the motor (999). The second observation value sequence (070) is determined by the first phase current (810) based on the phase and amplitude of the rotor position of the motor (999) and the first phase current (810).

2. The motor control method as described in claim 1, wherein: The second current reconstruction step (200) obtains the first intermediate current (113) of the two-phase stationary coordinate system from the first given current sequence (054) through the first transformation process (210), and obtains the second intermediate current (153) from the three-phase stationary coordinate system to the two-phase stationary coordinate system from the first phase current (810) through the second transformation process (220); and obtains the second observation value sequence (070) from the two-phase stationary coordinate system to the rotating coordinate system from the first intermediate current (113) and the second intermediate current (153) through the third transformation process (230).

3. The motor control method as described in claim 2, wherein: The first intermediate current (113) is the β-axis current given value (052) of the two-phase stationary coordinate system, i.e., i*β; the first given current sequence (054) is the dq given current vector of the rotating coordinate system, including the d-axis current given value (055) i.e., i*d and the q-axis current given value (057) i.e., i*q.

4. The motor control method as described in any one of claims 2 or 3, wherein: The reconstruction process obtains the rotor angle (099)θ of the motor (999) and the compensation angle (088)x of the first phase current (810); the compensation angle (088) is the electrical angle when the axis of the α phase of the two-phase stationary coordinate system coincides with the first phase current (810), and the first phase current (810) is one phase in the three-phase stationary coordinate system.

5. The motor control method as described in claim 4, wherein: When the compensation angle (088)x is equal to 0 degrees, the first phase axis of the stator of the motor (099) is aligned with the α phase axis as the vector control reference; when the compensation angle (088)x is equal to 240 degrees, the second phase axis of the stator is aligned with the α phase axis as the vector control reference.

6. The motor control method as described in any one of claims 1, 2, 3 or 5, wherein: The first current sensor sequence (700) further includes at least a second current sensor (720) and / or a third current sensor (730); the first current sequence (800) further includes at least a second phase current (820) of the second current sensor (720) and / or a third phase current (830) of the third current sensor (730); the vector control is implemented on the motor (999) by replacing the first phase current (810) with the second phase current (820) or the third phase current (830) and employing the second current reconstruction step (200).

7. The motor control method as described in claim 6 further includes a third fault diagnosis step (300); if the third fault diagnosis step (300) has diagnosed a faulty current sensor or a faulty sensor sequence in the first current sensor sequence (700), then the faulty current sensor or the current sensor in the faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection step (100) and / or the second current reconstruction step (200).

8. The motor control method according to any one of claims 1, 2, 3, 5 or 7, wherein: Based on the preset failure mode data (399), the relationship table (330) of the current sequence transformed from the first current sequence (800) to the corresponding current sequence in the two-phase stationary coordinate system is compared to locate the current sensor that has a fault or failure; the first phase and / or the second phase corresponding to the abnormal current value in the two-phase stationary coordinate system in the relationship table (330) is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failure state.

9. The motor control method as described in claim 8, wherein: If all current sensors in the first current sensor sequence (700) are faulty or fail, the vector control or the motor (999) is prohibited from running; the logic value in the relationship table (330) is obtained by comparing the confidence interval of the current corresponding to the relationship table (330) according to the probability distribution (388) corresponding to the failure mode data (399).

10. The motor control method according to any one of claims 1, 2, 3, 5, 7 or 9, wherein: The first transformation process (210) includes the process of using the inverse Park transformation (061), the second transformation process (220) includes the process of using the Clarke transformation (040), and the third transformation process (230) includes the process of using the Park transformation.

11. A detection and conversion device (600) includes a first current detection module (610) and a second current reconstruction module (620); the first current detection module (610) acquires a first current sequence (800) corresponding to a first current sensor sequence (700); the first current sensor sequence (700) includes at least a first current sensor (710), and the first current sequence (800) includes at least a first phase current (810) detected by the first current sensor (710); the second current reconstruction module (620) reconstructs the first phase current (810); the reconstruction process uses a second observation value sequence (070) corresponding to a first given current sequence (054) of a motor (999) vector control as a feedback signal to realize closed-loop control of the motor (999); the second observation value sequence (070) is determined by the first phase current (810) based on the rotor position of the motor (999) and the phase and amplitude of the first phase current (810).

12. The detection and transformation device (600) as described in claim 11, wherein: The second current reconstruction module (620) obtains the first intermediate current (113) of the two-phase stationary coordinate system from the first given current sequence (054) through the first transformation process (210), and obtains the second intermediate current (153) from the three-phase stationary coordinate system to the two-phase stationary coordinate system from the first phase current (810) through the second transformation process (220); and obtains the second observation value sequence (070) from the two-phase stationary coordinate system to the rotating coordinate system from the first intermediate current (113) and the second intermediate current (153) through the third transformation process (230); the first intermediate current (113) is the β-axis current given value (052) of the two-phase stationary coordinate system, i.e., i*β; the first given current sequence (054) is the dq given current vector of the rotating coordinate system, including the d-axis current given value (055) i*d and the q-axis current given value (057) i*q.

13. The detection and transformation device (600) as described in claim 12, wherein: The reconstruction process obtains the rotor angle (099) θ of the motor (999) and the compensation angle (088) x of the first phase current (810); the compensation angle (088) is the electrical angle when the α-phase axis of the two-phase stationary coordinate system coincides with the first phase current (810), and the first phase current (810) is one phase in the three-phase stationary coordinate system; when the compensation angle (088) x is equal to 0 degrees, the coincidence of the first phase axis of the stator of the motor (099) with the α-phase axis is taken as the vector control reference; when the compensation angle (088) x is equal to 240 degrees, the coincidence of the second phase axis of the stator with the α-phase axis is taken as the vector control reference.

14. The detection and conversion device (600) as described in any one of claims 11, 12 or 13, wherein: The first current sensor sequence (700) further includes at least a second current sensor (720) and / or a third current sensor (730); the first current sequence (800) further includes at least a second phase current (820) of the second current sensor (720) and / or a third phase current (830) of the third current sensor (730); the first phase current (810) is replaced by the second phase current (820) or the third phase current (830) and the vector control is implemented on the motor (999) using the second current reconstruction module (620).

15. The detection and conversion device (600) as claimed in claim 14 further includes a third fault diagnosis module (630); if the third fault diagnosis module (630) has diagnosed that there is a faulty current sensor or a faulty sensor sequence in the first current sensor sequence (700), then the faulty current sensor or the current sensor in the faulty sensor sequence is disabled or electrically isolated to prevent the corresponding current sensor or sensor sequence from participating in the processing of the first current detection module (610) and / or the second current reconstruction module (620).

16. The detection and transformation device (600) as claimed in claim 15, wherein: According to the preset failure mode data (399), the relationship table (330) corresponding to the current sequence transformed from the first current sequence (800) to the two-phase stationary coordinate system is compared to locate the current sensor that has a fault or failure. The first phase and / or the second phase in the relationship table (330) corresponding to the abnormal current value in the two-phase stationary coordinate system is "logical false", that is, the current sensor of the first phase and / or the second phase is in a failure state. If all current sensors in the first current sensor sequence (700) have a fault or failure, the vector control or the motor (999) is prohibited from running. The logical value in the relationship table (330) is obtained by comparing the confidence interval of the current corresponding to the relationship table (330) according to the probability distribution (388) corresponding to the failure mode data (399).

17. The detection and conversion device (600) as described in any one of claims 11, 12, 13, 15 or 16, wherein: The first transformation process (210) includes the process of using the inverse Park transformation (061), the second transformation process (220) includes the process of using the Clarke transformation (040), and the third transformation process (230) includes the process of using the Park transformation.

18. A computer storage medium (903) comprising a storage medium body for storing a computer program; wherein the computer program, when executed by a microprocessor, implements the motor control method as described in any one of claims 1 to 10.

19. A controller (901) comprising the detection and conversion device (600) as claimed in any one of claims 11 to 17; and / or the computer storage medium (903) as claimed in claim 18.

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