Phase Loss Detection Method and System for Electronic Oil Pump Motor

Abstract

The present invention provides a method and system for detecting phase loss of an electronic oil pump motor, including: acquiring three-phase currents of the electronic oil pump motor based on dual-resistance sampling; determining whether the sum of the absolute values of the three-phase currents is less than a first threshold; if so, determining that the electronic oil pump motor has a phase loss; if not, determining a second threshold in a preset correspondence table based on the current operating condition of the electronic oil pump motor; the preset correspondence table is a correspondence table between the operating conditions of the electronic oil pump motor and the second threshold; determining whether the absolute value of the difference between the sum of the positive currents and the sum of the negative currents in the three-phase currents is less than the second threshold; if so, determining that the electronic oil pump motor has a phase loss. The present invention alleviates the technical problem that the diagnostic method with a fixed threshold in the prior art may fail under different operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic oil pump motor control, and more particularly to a method and system for detecting phase loss of an electronic oil pump motor. Background Art

[0002] In actual operation, the automotive electronic oil pump motor may encounter the fault of drive motor phase loss. When the motor is phase-loss, it will affect the operation of the motor, and the oil pump will vibrate, affecting the oil supply of the oil pump. The control method of the permanent magnet synchronous motor mainly adopts the FOC (Field-Oriented Control) method based on vector control, that is, the field-oriented control algorithm. The method for detecting motor phase loss mainly samples the three-phase current of the motor and then makes a judgment. The prior art involves less in the diagnosis of motor phase loss. For the convenience of engineering application, the fault diagnosis usually adopts the threshold method. However, under different operating conditions, the control system is affected by the operating conditions, and the original fault detection strategy may fail to diagnose the fault. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method and system for detecting phase loss of an electronic oil pump motor, so as to alleviate the technical problem that the diagnostic method with a fixed threshold may fail under different operating conditions existing in the prior art.

[0004] In a first aspect, an embodiment of the present invention provides a method for detecting phase loss of an electronic oil pump motor, including: obtaining the three-phase current of the electronic oil pump motor based on double-resistance sampling; determining whether the sum of the absolute values of the three-phase current is less than a first threshold; if so, determining that the electronic oil pump motor is phase-loss; if not, determining a second threshold in a preset correspondence table based on the current operating condition of the electronic oil pump motor; the preset correspondence table is a correspondence table between the operating condition of the electronic oil pump motor and the second threshold; determining whether the absolute value of the difference between the sum of the positive currents and the sum of the negative currents in the three-phase current is less than the second threshold; if so, determining that the electronic oil pump motor is phase-loss.

[0005] Further, the three-phase current includes: the first-phase current, the second-phase current and the third-phase current; obtaining the three-phase current of the electronic oil pump motor based on double-resistance sampling includes: obtaining the first-phase current and the second-phase current of the electronic oil pump motor based on double-resistance sampling; determining the third-phase current of the electronic oil pump motor based on the first-phase current, the second-phase current and Kirchhoff's current law.

[0006] Further, the method further includes: if it is determined that the sum of the absolute values of the three-phase current is greater than or equal to the first threshold, and the absolute value of the difference between the sum of the positive currents and the sum of the negative currents in the three-phase current is greater than or equal to the second threshold, determining that the electronic oil pump motor is not phase-loss.

[0007] Further, the method further includes: optimizing the preset correspondence table based on a state analysis method.

[0008] Further, the operating condition of the electronic oil pump motor is the rotational speed of the electronic oil pump; optimizing the preset correspondence table based on a state analysis method includes: dividing the rotational speed of the electronic oil pump from the lowest rotational speed to the highest rotational speed into multiple rotational speed points at intervals of a preset rotational speed range; starting the electronic oil pump motor to operate at the rotational speed corresponding to the first rotational speed point; the first rotational speed point is one of the multiple rotational speed points; after the operation of the electronic oil pump motor is stable, removing one of the three-phase power supplies of the electronic oil pump motor; performing a single-phase loss detection on the electronic oil pump motor based on the corresponding second threshold in the preset correspondence table; if the single-phase loss of the electronic oil pump motor is not detected, increasing and updating the second threshold by a preset percentage until the single-phase loss of the electronic oil pump motor can be detected; if the single-phase loss of the electronic oil pump motor is detected, optimizing the second threshold corresponding to the next rotational speed point of the first rotational speed point.

[0009] Further, the operating condition of the electronic oil pump motor is the input voltage of the electronic oil pump; optimizing the preset correspondence table based on a state analysis method includes: dividing the input voltage of the electronic oil pump from the lowest voltage to the highest voltage into multiple voltage reference points at intervals of a preset voltage range; starting the electronic oil pump motor to operate at the input voltage corresponding to the first voltage reference point; the first voltage reference point is one of the multiple voltage reference points; after the operation of the electronic oil pump motor is stable, removing one of the three-phase power supplies of the electronic oil pump motor; performing a single-phase loss detection on the electronic oil pump motor based on the corresponding second threshold in the preset correspondence table; if the single-phase loss of the electronic oil pump motor is not detected, increasing and updating the second threshold by a preset percentage until the single-phase loss of the electronic oil pump motor can be detected; if the single-phase loss of the electronic oil pump motor is detected, optimizing the second threshold corresponding to the next voltage reference point of the first voltage reference point.

[0010] Second aspect, an embodiment of the present invention further provides a phase loss detection system for an electronic oil pump motor, including: an acquisition module, a first judgment module, a determination module, and a second judgment module; wherein, the acquisition module is configured to acquire three-phase currents of the electronic oil pump motor based on double-resistance sampling; the first judgment module is configured to judge whether the sum of the absolute values of the three-phase currents is less than a first threshold; if so, it is determined that the electronic oil pump motor is phase-lost; the determination module is configured to determine a second threshold in a preset correspondence table based on the current working condition of the electronic oil pump motor; the preset correspondence table is a correspondence table between the working conditions of the electronic oil pump motor and the second threshold; the second judgment module is configured to, if the sum of the absolute values of the three-phase currents is greater than or equal to the first threshold, judge whether the difference between the absolute value of the sum of the positive currents and the absolute value of the sum of the negative currents in the three-phase currents is less than the second threshold; if so, it is determined that the electronic oil pump motor is phase-lost.

[0011] Further, the system further includes an optimization module configured to optimize the preset correspondence table based on a state analysis method.

[0012] Third aspect, an embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the steps of the method described in the first aspect above are implemented.

[0013] Fourth aspect, an embodiment of the present invention further provides a computer-readable medium having non-volatile program code executable by a processor, and the program code causes the processor to execute the method described in the first aspect above.

[0014] The present invention provides a phase loss detection method and system for an electronic oil pump motor. By analyzing and judging the collected three-phase currents, the correct detection threshold can be selected under different working conditions, ensuring that the system can accurately detect the phase loss fault of the permanent magnet synchronous motor, and alleviating the technical problem that the diagnostic method with a fixed threshold may fail under different operating conditions in the prior art. Description of the Drawings

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 It is a flowchart of a phase loss detection method for an electronic oil pump motor provided by an embodiment of the present invention;

[0017] Figure 2 The first flowchart for optimizing a preset correspondence table provided by an embodiment of the present invention;

[0018] Figure 3 The second flowchart for optimizing a preset correspondence table provided by an embodiment of the present invention;

[0019] Figure 4 The schematic diagram of a phase loss detection system for an electronic oil pump motor provided by an embodiment of the present invention;

[0020] Figure 5 The schematic diagram of another phase loss detection system for an electronic oil pump motor provided by an embodiment of the present invention. Detailed implementation manners

[0021] Next, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1:

[0023] Figure 1 It is the flowchart of a phase loss detection method for an electronic oil pump motor provided by an embodiment of the present invention. As Figure 1 shown, the method specifically includes the following steps:

[0024] Step S102, based on double-resistance sampling, obtain the three-phase current of the electronic oil pump motor.

[0025] Step S104, determine whether the sum of the absolute values of the three-phase current is less than a first threshold; if so, execute step S106; if not, execute step S108.

[0026] Step S106, determine that the electronic oil pump motor is phase-loss.

[0027] Optionally, after determining that the electronic oil pump motor is phase-loss, the method provided by the embodiment of the present invention further includes: feedback, through a controller, that the electronic oil pump motor has a phase-loss fault.

[0028] Step S108, based on the current working condition of the electronic oil pump motor, determine a second threshold in a preset correspondence table; the preset correspondence table is the correspondence table between the working conditions of the electronic oil pump motor and the second threshold;

[0029] Step S110, determine whether the difference between the absolute value of the sum of positive currents and the absolute value of the sum of negative currents in the three-phase current is less than a second threshold; if so, execute step S106; if not, execute step S112.

[0030] Step S112, determine that the electronic oil pump motor is not open-phase. At this time, the electronic oil pump motor keeps running normally.

[0031] The present invention provides a method for detecting open-phase of an electronic oil pump motor. By analyzing and judging the collected three-phase current, the correct detection threshold can be selected under different working conditions, ensuring that the system can accurately detect the open-phase fault of the permanent magnet synchronous motor, and alleviating the technical problem that the diagnostic method with a fixed threshold may fail under different operating conditions in the prior art.

[0032] In the embodiment of the present invention, the three-phase current includes: the first-phase current, the second-phase current, and the third-phase current. Step S102 further includes the following steps:

[0033] Step S1021, based on double-resistance sampling, obtain the first-phase current and the second-phase current of the electronic oil pump motor.

[0034] Step S1022, based on the first-phase current, the second-phase current, and Kirchhoff's current law, determine the third-phase current of the electronic oil pump motor.

[0035] In the embodiment of the present invention, first, through double-resistance sampling, the two-phase currents i a , i b of the electronic oil pump motor are collected, and the current i c of the last phase is calculated through Kirchhoff's current law. Calculate I = |i a | + |i b | + |i c |. If I is less than the first threshold N1 for detecting open-phase, it is determined that the electronic oil pump motor is open-phase. If I is greater than or equal to the first threshold N1, enter the correction judgment: first, judge the positive and negative of the collected three-phase current, and respectively obtain the sum i + of positive currents and the sum i - of negative currents, and take the difference between the absolute values of the two to get I r = |i + | - |i - |. Compare I r with the second threshold. If I r is less than the second threshold, it is determined that the motor is open-phase.

[0036] Optionally, the method provided by the embodiments of the present invention further includes the following steps: optimizing the preset correspondence table based on the state analysis method. In the embodiments of the present invention, the operating conditions of the electric oil pump motor include the rotation speed of the electric oil pump and the input voltage of the electric oil pump; for different operating conditions, the embodiments of the present invention provide two optimization methods.

[0037] Optionally, Figure 2 FIG. 5 is a flowchart for optimizing the preset correspondence table according to the first embodiment of the present invention. As Figure 2 shown, if the operating condition of the electric oil pump motor is the rotation speed of the electric oil pump, then optimizing the preset correspondence table based on the state analysis method includes the following steps:

[0038] Step S201: Divide the rotation speed of the electric oil pump from the lowest rotation speed to the highest rotation speed into multiple rotation speed points at intervals of a preset rotation speed range;

[0039] Step S202: Start the electric oil pump motor to operate at the rotation speed corresponding to the first rotation speed point; the first rotation speed point is one of the multiple rotation speed points;

[0040] Step S203: After the operation of the electric oil pump motor is stable, remove one of the three-phase power supplies of the electric oil pump motor;

[0041] Step S204: Based on the corresponding second threshold value in the preset correspondence table, perform a single-phase loss detection on the electric oil pump motor; if no single-phase loss of the electric oil pump motor is detected, then execute Step S205; if a single-phase loss of the electric oil pump motor is detected, then execute Step S206;

[0042] Step S205: Increase and update the second threshold value by a preset percentage until a single-phase loss of the electric oil pump motor can be detected;

[0043] Step S206: Optimize the second threshold value corresponding to the next rotation speed point of the first rotation speed point.

[0044] In the embodiments of the present invention, since the load of the electronic oil pump and the input DC voltage will affect the three-phase current level of the motor, when the load and voltage increase to a certain level, the current threshold will fail. Therefore, it is necessary to optimize the phase loss threshold under different working conditions. The method provided by the embodiments of the present invention mainly optimizes the second threshold because the second threshold can more accurately detect the phase loss fault of the motor under loading and pressurization compared to the first threshold. Specifically, first, the threshold is optimized under different loads. The higher the rotational speed of the permanent magnet synchronous motor, the higher the pump body pressure, and the higher the load. Therefore, by increasing the rotational speed of the oil pump, with every 500 rpm as a point, the rotational speed of the permanent magnet synchronous motor is increased. After stabilization, one phase of the motor is removed. If a phase loss is diagnosed, the threshold optimization of the next speed point is entered. If no phase loss is diagnosed, the second threshold is increased by 5%, and the test is repeated until a phase loss is diagnosed, and the optimized second threshold under the current rotational speed condition is obtained. Finally, the optimized second threshold under different rotational speed conditions is obtained, improving the accuracy of phase loss detection.

[0045] Optionally, Figure 3 FIG. is a flowchart of the second method for optimizing the preset correspondence table according to the embodiments of the present invention. As Figure 3 shown, the working condition of the electronic oil pump motor is the input voltage of the electronic oil pump; then, the preset correspondence table is optimized based on the state analysis method, including the following steps:

[0046] Step S301: Divide the input voltage of the electronic oil pump from the lowest voltage to the highest voltage into multiple voltage reference points at intervals of a preset voltage range;

[0047] Step S302: Start the electronic oil pump motor to run at the input voltage corresponding to the first voltage reference point; the first voltage reference point is one of the multiple voltage reference points;

[0048] Step S303: After the electronic oil pump motor runs stably, remove one of the three-phase power supplies of the electronic oil pump motor;

[0049] Step S304: Based on the corresponding second threshold in the preset correspondence table, perform a phase loss detection on the electronic oil pump motor; if no phase loss of the electronic oil pump motor is detected, execute Step S305; if a phase loss of the electronic oil pump motor is detected, execute Step S306;

[0050] Step S305: Increase and update the second threshold by a preset percentage until a phase loss of the electronic oil pump motor can be detected;

[0051] Step S306: Optimize the second threshold corresponding to the next voltage reference point of the first voltage reference point.

[0052] In the embodiments of the present invention, for different operating conditions of the input voltage of the oil pump, with 0.5V as a reference recording point, first make the permanent magnet synchronous motor operate stably, increase the input voltage, and remove one phase of the motor after stabilization. If a phase loss is diagnosed, enter the threshold optimization of the next voltage point. If no phase loss is diagnosed, increase the second threshold by 5%, repeat the test until a phase loss is diagnosed, and obtain the optimized second threshold under the current voltage condition. Obtain the optimized second thresholds under different input voltage conditions at the current rotational speed condition. The intermediate condition of the reference point can be obtained according to the ratio.

[0053] As can be seen from the above description, the embodiments of the present invention provide a method for detecting phase loss of an electronic oil pump motor, which determines whether a phase loss occurs by comparing the sum of the absolute values of the three-phase currents with a first threshold, and performs correction detection by comparing the difference between the positive and negative currents with a second threshold. Compared with the existing strategies, this method is simple to operate, easy to implement in the control software, and the detection is accurate and reliable. The method provided by the embodiments of the present invention has the following technical effects compared with the prior art:

[0054] 1. It can ensure the safety of the high-speed operation of the electronic oil pump and improve the system safety;

[0055] 2. A threshold optimization method is added, which can adapt to different operating conditions and improve the applicable range of the control system.

[0056] Embodiment 2:

[0057] Figure 4 It is a schematic diagram of a system for detecting phase loss of an electronic oil pump motor provided according to an embodiment of the present invention. As Figure 4 shown, the system includes: an acquisition module 10, a first judgment module 20, a determination module 30, and a second judgment module 40.

[0058] Specifically, the acquisition module 10 is configured to acquire the three-phase currents of the electronic oil pump motor based on double-resistance sampling.

[0059] The first judgment module 20 is configured to judge whether the sum of the absolute values of the three-phase currents is less than a first threshold; if so, it is determined that the electronic oil pump motor is phase-lost.

[0060] The determination module 30 is configured to determine a second threshold in a preset correspondence table based on the current operating condition of the electronic oil pump motor; the preset correspondence table is a correspondence table between the operating conditions of the electronic oil pump motor and the second threshold.

[0061] The second judgment module 40 is configured to, if the sum of the absolute values of the three-phase currents is greater than or equal to the first threshold, judge whether the difference between the absolute value of the sum of the positive currents and the absolute value of the sum of the negative currents in the three-phase currents is less than the second threshold; if so, it is determined that the electronic oil pump motor is phase-lost.

[0062] The present invention provides a phase loss detection system for an electronic oil pump motor. By analyzing and judging the collected three-phase current, the correct detection threshold can be selected under different working conditions, ensuring that the system can accurately detect the phase loss fault of the permanent magnet synchronous motor, and alleviating the technical problem that the diagnostic method with a fixed threshold in the prior art may fail under different operating conditions.

[0063] In an embodiment of the present invention, the three-phase current includes: the first-phase current, the second-phase current, and the third-phase current. The acquisition module 10 is further configured to: based on double-resistance sampling, acquire the first-phase current and the second-phase current of the electronic oil pump motor; and determine the third-phase current of the electronic oil pump motor based on the first-phase current, the second-phase current, and Kirchhoff's current law.

[0064] Figure 5 It is a schematic diagram of another phase loss detection system for an electronic oil pump motor according to an embodiment of the present invention. As Figure 5 shown, the system further includes an optimization module 50 for optimizing the preset correspondence table based on the state analysis method. In an embodiment of the present invention, the working conditions of the electronic oil pump motor include the rotation speed of the electronic oil pump and the input voltage of the electronic oil pump.

[0065] As Figure 5 shown, the optimization module 50 further includes: a first optimization unit 51 and a second optimization unit 52.

[0066] Specifically, the first optimization unit 51 is configured to: divide the rotation speed of the electronic oil pump from the lowest rotation speed to the highest rotation speed into multiple rotation speed points at intervals of a preset rotation speed range; start the electronic oil pump motor to operate at the rotation speed corresponding to the first rotation speed point; the first rotation speed point is one of the multiple rotation speed points; after the operation of the electronic oil pump motor is stable, remove one of the three-phase powers of the electronic oil pump motor; based on the corresponding second threshold in the preset correspondence table, perform phase loss detection on the electronic oil pump motor; if no phase loss of the electronic oil pump motor is detected, increase and update the second threshold by a preset percentage until the phase loss of the electronic oil pump motor can be detected; if the phase loss of the electronic oil pump motor is detected, perform optimization of the second threshold corresponding to the next rotation speed point of the first rotation speed point.

[0067] A second optimization unit 52 is configured to: divide the input voltage of the electronic oil pump from the lowest voltage to the highest voltage into multiple voltage reference points at intervals of a preset voltage range; start the electronic oil pump motor to operate at the input voltage corresponding to the first voltage reference point, where the first voltage reference point is one of the multiple voltage reference points; after the operation of the electronic oil pump motor is stable, disconnect one of the three-phase power supplies of the electronic oil pump motor; perform open-phase detection on the electronic oil pump motor based on a second threshold value corresponding in a preset correspondence table; if no open-phase of the electronic oil pump motor is detected, increase and update the second threshold value by a preset percentage until an open-phase of the electronic oil pump motor can be detected; if an open-phase of the electronic oil pump motor is detected, perform optimization of the second threshold value corresponding to the next voltage reference point of the first voltage reference point.

[0068] An embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method in the first embodiment above are implemented.

[0069] An embodiment of the present invention further provides a computer-readable medium having non-volatile program code executable by a processor, and the program code causes the processor to execute the method in the first embodiment above.

[0070] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting phase loss of an electronic oil pump motor, characterized in that, it includes: Based on double-resistance sampling, obtain the three-phase current of the electronic oil pump motor; Judge whether the sum of the absolute values of the three-phase current is less than a first threshold; If so, determine that the electronic oil pump motor has a phase loss; If not, based on the current working condition of the electronic oil pump motor, determine a second threshold in a preset correspondence table; the preset correspondence table is a correspondence table between the working conditions of the electronic oil pump motor and the second threshold; Judge whether the difference between the absolute value of the sum of the positive currents and the absolute value of the sum of the negative currents in the three-phase current is less than the second threshold; If so, determine that the electronic oil pump motor has a phase loss.

2. The method according to claim 1, characterized in that, The three-phase current includes: a first-phase current, a second-phase current and a third-phase current; based on double-resistance sampling, obtaining the three-phase current of the electronic oil pump motor includes: Based on double-resistance sampling, obtain the first-phase current and the second-phase current of the electronic oil pump motor; Based on the first-phase current, the second-phase current and Kirchhoff's current law, determine the third-phase current of the electronic oil pump motor.

3. The method according to claim 1, characterized in that, The method further includes: If it is judged that the sum of the absolute values of the three-phase current is greater than or equal to the first threshold, and the difference between the absolute value of the sum of the positive currents and the absolute value of the sum of the negative currents in the three-phase current is greater than or equal to the second threshold, then determine that the electronic oil pump motor has no phase loss.

4. The method according to claim 1, characterized in that, The method further includes: optimizing the preset correspondence table based on the state analysis method; The working condition of the electronic oil pump motor is the rotational speed of the electronic oil pump; optimizing the preset correspondence table based on the state analysis method includes: Taking a preset rotational speed interval as an interval, divide the rotational speed of the electronic oil pump from the lowest rotational speed to the highest rotational speed into multiple rotational speed points; Start the electronic oil pump motor to run at the rotational speed corresponding to the first rotational speed point; the first rotational speed point is one of the multiple rotational speed points; After the operation of the electronic oil pump motor is stable, remove one of the three-phase power supplies of the electronic oil pump motor; Based on the corresponding second threshold in the preset correspondence table, perform phase-loss detection on the electronic oil pump motor; If the electronic oil pump motor is not detected to have a phase loss, then increase and update the second threshold by a preset percentage until the electronic oil pump motor can be detected to have a phase loss; If the electronic oil pump motor is detected to have a phase loss, then perform optimization of the second threshold corresponding to the next rotational speed point of the first rotational speed point.

5. The method according to claim 4, characterized in that, The working condition of the electronic oil pump motor is the input voltage of the electronic oil pump; Optimizing the preset correspondence table based on the state analysis method includes: Taking a preset voltage interval as an interval, divide the input voltage of the electronic oil pump from the lowest voltage to the highest voltage into multiple voltage reference points; Start the electronic oil pump motor to operate at the input voltage corresponding to the first voltage reference point; the first voltage reference point is one of the multiple voltage reference points; After the operation of the electronic oil pump motor is stable, remove one of the three-phase power supplies of the electronic oil pump motor; Based on the corresponding second threshold value in the preset correspondence table, perform open-phase detection on the electronic oil pump motor; If it is not detected that the electronic oil pump motor is open-phased, increase and update the second threshold value by a preset percentage until it can be detected that the electronic oil pump motor is open-phased; If it is detected that the electronic oil pump motor is open-phased, perform optimization of the second threshold value corresponding to the next voltage reference point of the first voltage reference point.

6. An open-phase detection system for an electronic oil pump motor, Characterized in that, It includes: An acquisition module, a first judgment module, a determination module and a second judgment module; wherein, The acquisition module is used to acquire the three-phase current of the electronic oil pump motor based on double-resistance sampling; The first judgment module is used to judge whether the sum of the absolute values of the three-phase current is less than a first threshold value; if so, it is determined that the electronic oil pump motor is open-phased; The determination module is used to determine a second threshold value in a preset correspondence table based on the current working condition of the electronic oil pump motor; the preset correspondence table is a correspondence table between the working condition of the electronic oil pump motor and the second threshold value; The second judgment module is used to judge whether the difference between the absolute value of the sum of the positive currents and the absolute value of the sum of the negative currents in the three-phase current is less than the second threshold value if the sum of the absolute values of the three-phase current is greater than or equal to the first threshold value; if so, it is determined that the electronic oil pump motor is open-phased.

7. The system according to claim 6, Characterized in that, The system further includes an optimization module for optimizing the preset correspondence table based on the state analysis method; The working condition of the electronic oil pump motor is the rotational speed of the electronic oil pump; Optimizing the preset correspondence table based on the state analysis method includes: Dividing the rotational speed of the electronic oil pump from the lowest rotational speed to the highest rotational speed into multiple rotational speed points at intervals of a preset rotational speed range; Start the electronic oil pump motor to operate at the rotational speed corresponding to the first rotational speed point; the first rotational speed point is one of the multiple rotational speed points; After the operation of the electronic oil pump motor is stable, remove one of the three-phase power supplies of the electronic oil pump motor; Based on the corresponding second threshold value in the preset correspondence table, perform open-phase detection on the electronic oil pump motor; If it is not detected that the electronic oil pump motor is open-phased, increase and update the second threshold value by a preset percentage until it can be detected that the electronic oil pump motor is open-phased; If it is detected that the electronic oil pump motor is open-phased, perform optimization of the second threshold value corresponding to the next rotational speed point of the first rotational speed point.

8. An electronic device, including a memory, a processor and a computer program stored on the memory and executable on the processor, Characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5 above.

9. A computer-readable medium having non-volatile program code executable by a processor, wherein, the program code causes the processor to execute the method according to any one of claims 1-5.

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