A power chip control system and method

Abstract

The application provides a power chip control system and method, the power chip control system comprises a motor three-phase circuit and a processing module; when the power chip enters an ASC state, the processing module controls a first three-tube group to be turned on, a second three-tube group to be turned off, and calculates a first-phase current of a first phase, a second-phase current of a second phase and a third-phase current of a third phase; the processing module selects one phase with a current maximum value from the first-phase current, the second-phase current and the third-phase current as a maximum current phase, and when the current maximum value is greater than or equal to a preset safety turn-off threshold value, the processing module controls the first three-tube group to be turned off and the second three-tube group to be turned on; the processing module further continuously monitors the first-phase current, the second-phase current and the third-phase current, and repeatedly switches one of the first three-tube group and the second three-tube group to be turned on and the other to be turned off based on a preset control strategy. After the above technical scheme is adopted, the motor controller overheating failure is avoided, and the IGBT life in a fault state is increased.

Description

Technical Field

[0001] This invention relates to the field of vehicle control, and more particularly to a power chip control system and method. Background Technology

[0002] In the electric drive system of new energy vehicles, the normal operation of the motor is extremely important. Once the motor fails, it can cause system abnormalities at best, and vehicle destruction and loss of life at worst.

[0003] Therefore, in the event of a motor failure, active protection of the electric drive system is required. The most common active protection measure is ASC (Active Short Circuit). ASC isolates the motor and controller by short-circuiting either the upper or lower axle, preventing unexpected damage to the controller and also preventing unexpected torque from the vehicle, thus entering a safe state.

[0004] During the ASC process, the excessive current in the first cycle will cause serious IGBT overheating. Furthermore, when there is a large steady-state ASC current, the uneven heating of various components in the electric drive system will cause the motor controller to overheat and fail.

[0005] Therefore, a new control system and method for power chips under ASC is needed. By controlling the switching transistors with ASC short circuit to switch at reasonable times, the ASC conduction current is distributed between the upper and lower switching transistors to reduce the thermal stress of individual switching transistors and thus extend the lifespan of the power chip. Summary of the Invention

[0006] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a power chip control system and method to avoid overheating failure of motor controller and increase the life of IGBT under fault conditions.

[0007] This invention discloses a power chip control system, which includes a three-phase motor circuit and a processing module;

[0008] A three-phase circuit for a motor includes the first phase, the second phase, and the third phase.

[0009] The first phase includes a first IGBT chip and a second IGBT chip connected in series, wherein the first IGBT chip includes a first switching transistor and a first diode connected in parallel, and the second IGBT chip includes a second switching transistor and a second diode connected in parallel.

[0010] The second phase includes a third IGBT chip and a fourth IGBT chip connected in series, wherein the third IGBT chip includes a third switch and a third diode connected in parallel, and the fourth IGBT chip includes a fourth switch and a fourth diode connected in parallel.

[0011] The third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series, wherein the fifth IGBT chip includes a fifth switching transistor and a fifth diode connected in parallel, and the sixth IGBT chip includes a sixth switching transistor and a sixth diode connected in parallel.

[0012] When a vehicle drive system with a power chip malfunctions, causing the power chip to enter the ASC state, the processing module controls the first three-transistor group composed of the first, third, and fifth switches to turn on, and the second three-transistor group composed of the second, fourth, and sixth switches to turn off, and calculates the first phase current of the first phase, the second phase current of the second phase, and the third phase current of the third phase.

[0013] The processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the phase with the maximum current value. When the maximum current value is greater than or equal to the preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on.

[0014] The processing module also continuously monitors the first phase current, the second phase current, and the third phase current, and repeatedly switches one of the first three-transistor group and the second three-transistor group to be on and the other to be off based on a preset control strategy.

[0015] Preferably, the processing module obtains the magnitudes of the first phase current, the second phase current, and the third phase current, and selects the phase with the largest absolute value as the phase with the largest current.

[0016] When the maximum current value of the phase with the maximum current is greater than or equal to the safety shutdown threshold, the processing module controls the first three-phase group to shut down and the second three-phase group to turn on. This control operation is recorded as the first switching.

[0017] Preferably, the control strategy includes:

[0018] The processing module has a preset current zero-crossing threshold, which is greater than 0 and approximately equal to 0.

[0019] When the absolute value of the maximum current is less than the current zero-crossing threshold, or the maximum current is in reverse phase, and the absolute values ​​of the currents in the other two phases besides the phase with the maximum current are less than or equal to the safety turn-off threshold, the processing module switches the first three-phase group and the second three-phase group to be turned on or off.

[0020] Preferably, the control strategy further includes:

[0021] The processing module has a preset time threshold;

[0022] Each time the processing module switches the first three-tube group and the second three-tube group on or off, it starts timing for one switching time.

[0023] The processing module switches the first three-tube group and the second three-tube group on or off only when the switching time is greater than or equal to the time threshold.

[0024] Preferably, the time threshold is less than or equal to 1 / 2 of the sinusoidal period of the current in the three-phase circuit of the motor.

[0025] This invention also discloses a power chip control method, comprising the following steps:

[0026] The motor three-phase circuit is configured as follows: The motor three-phase circuit includes a first phase, a second phase, and a third phase; the first phase includes a first IGBT chip and a second IGBT chip connected in series, wherein the first IGBT chip includes a first switching transistor and a first diode connected in parallel, and the second IGBT chip includes a second switching transistor and a second diode connected in parallel; the second phase includes a third IGBT chip and a fourth IGBT chip connected in series, wherein the third IGBT chip includes a third switching transistor and a third diode connected in parallel, and the fourth IGBT chip includes a fourth switching transistor and a fourth diode connected in parallel; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series, wherein the fifth IGBT chip includes a fifth switching transistor and a fifth diode connected in parallel, and the sixth IGBT chip includes a sixth switching transistor and a sixth diode connected in parallel.

[0027] When a vehicle drive system with a power chip malfunctions, causing the power chip to enter the ASC state, a processing module controls the first three-transistor group composed of the first, third, and fifth switches to turn on, and the second three-transistor group composed of the second, fourth, and sixth switches to turn off, and calculates the first phase current of the first phase, the second phase current of the second phase, and the third phase current of the third phase.

[0028] The processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the phase with the maximum current value. When the maximum current value is greater than or equal to the preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on.

[0029] The processing module also continuously monitors the first phase current, the second phase current, and the third phase current, and repeatedly switches one of the first three-transistor group and the second three-transistor group to be on and the other to be off based on a preset control strategy.

[0030] Preferably, the processing module selects the phase with the maximum current value among the first phase current, second phase current, and third phase current as the maximum current phase, and when the maximum current value is greater than or equal to a preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on, including the following steps:

[0031] The processing module obtains the magnitudes of the first-phase current, the second-phase current, and the third-phase current, and selects the phase with the largest absolute value as the phase with the largest current.

[0032] When the maximum current value of the phase with the maximum current is greater than or equal to the safety shutdown threshold, the processing module controls the first three-phase group to shut down and the second three-phase group to turn on. This control operation is recorded as the first switching.

[0033] Preferably, the control strategy includes:

[0034] The processing module has a preset current zero-crossing threshold, which is greater than 0 and approximately equal to 0.

[0035] When the absolute value of the maximum current is less than the current zero-crossing threshold, or the maximum current is in reverse phase, and the absolute values ​​of the currents in the other two phases besides the phase with the maximum current are less than or equal to the safety turn-off threshold, the processing module switches the first three-phase group and the second three-phase group to be turned on or off.

[0036] Preferably, the control strategy further includes:

[0037] The processing module has a preset time threshold;

[0038] Each time the processing module switches the first three-tube group and the second three-tube group on or off, it starts timing for one switching time.

[0039] The processing module switches the first three-tube group and the second three-tube group on or off only when the switching time is greater than or equal to the time threshold.

[0040] Preferably, the time threshold is less than or equal to 1 / 2 of the sinusoidal period of the current in the three-phase circuit of the motor.

[0041] Compared with existing technologies, the above technical solution has the following advantages:

[0042] 1. By controlling the switching transistors with ASC short circuit to switch at reasonable times, the ASC conduction current is distributed between the upper and lower switching transistors, thereby reducing the thermal stress on individual switching transistors and enhancing IGBT lifespan.

[0043] 2. To prevent the risk of transient overheating;

[0044] 3. For some motors whose short-circuit current is much larger than their normal operating current, the above solution can be used to avoid overheating under long-term ASC conditions. Attached Figure Description

[0045] Figure 1 To conform to the three-phase circuit topology of the motor in a preferred embodiment of the present invention;

[0046] Figure 2 A schematic diagram of single-tube loss in a preferred embodiment of the present invention;

[0047] Figure 3To conform to the current waveform diagrams of the first phase current, the second phase current, and the third phase current in a preferred embodiment of the present invention;

[0048] Figure 4 A flowchart illustrating the power chip control method in a preferred embodiment of the present invention. Detailed Implementation

[0049] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0050] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0051] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0052] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0053] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0055] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0056] See Figure 1 The diagram shows a three-phase motor circuit included in the power chip control system, which includes a first phase, a second phase, and a third phase.

[0057] - The first phase includes a first IGBT chip and a second IGBT chip connected in series. The first IGBT chip includes a first switch and a first diode connected in parallel with opposite current flows. The second IGBT chip includes a second switch and a second diode connected in parallel with opposite current flows. That is, when the first switch is turned on, the first diode is turned off, and vice versa.

[0058] - The second phase includes a third IGBT chip and a fourth IGBT chip connected in series. The third IGBT chip includes a third switch and a third diode connected in parallel with opposite current flows. The fourth IGBT chip includes a fourth switch and a fourth diode connected in parallel with opposite current flows.

[0059] - The third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series. The fifth IGBT chip includes a fifth switch and a fifth diode connected in parallel with opposite current flows. The sixth IGBT chip includes a sixth switch and a sixth diode connected in parallel with opposite current flows.

[0060] It is understandable that the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip described above can also be integrated chips formed by multiple IGBTs connected in parallel.

[0061] When a vehicle drive system with a power chip malfunctions, causing the power chip to enter ASC state, according to ASC protection measures, either the upper three transistors or the lower three transistors will be turned on, while the other group will be turned off. This is controlled by the processing module: the first three transistor group (comprising the first, third, and fifth transistors) will be turned on, while the second three transistor group (comprising the second, fourth, and sixth transistors) will be turned off. (It can be understood that the first, third, and fifth transistors can be considered the upper three transistors, and the second, fourth, and sixth transistors the lower three transistors.) (The three transistors, or the first, third, and fifth switching transistors are considered the lower three transistors, and the second, fourth, and sixth switching transistors are considered the upper three transistors, but this is not limited to the upper and lower distinctions.) When the first three transistors are turned on, the current in the first, third, and fifth switching transistors will be concentrated on them. In particular, as mentioned above, after the transient current increases, a large amount of heat will be generated on the first, third, and fifth switching transistors. At this time, since the second, fourth, and sixth switching transistors are turned off, no current flows through them, and the heat is relatively small.

[0062] Therefore, based on the above situation, the processing module will perform the following operations: after entering the ASC state, obtain the current values ​​of the first phase current, the second phase current, and the third phase current respectively flowing through the first phase, the second phase current, and the third phase current, and after comparison, determine which phase current is the largest. The phase with the largest current value is recorded as the current maximum value, and the current value of that phase is continuously observed. At the same time, the phase with the current maximum value is recorded as the maximum current phase. That is, the processing module knows which phase current value is the largest and what the maximum current value is. The processing module also has a preset safety shutdown threshold. This threshold prevents excessive heat generation on the switching transistors when the current exceeds this value, potentially causing significant damage to the power chip (or the user can set this value arbitrarily according to their needs). When the processing module detects a maximum current value greater than or equal to the preset safety shutdown threshold, it switches the conducting transistor group, controlling the first three-transistor group to turn off and the second three-transistor group to turn on. After the first three-transistor group turns off, no current flows through it, and no heat is generated, thus reducing its thermal stress. However, after the second three-transistor group turns on, current flows through it, and the heat is "transferred" to it. In other words, in ASC mode, when heat cannot be completely eliminated, switching the heat source from the first three-transistor group to the second three-transistor group balances the heat distribution.

[0063] Furthermore, during the first IGBT cycle after entering ASC, heat will still be generated on the second and third phase transistor groups after the switching of the switching transistor groups. Therefore, the processing module will continuously monitor the values ​​of the first-phase current, second-phase current, and third-phase current, and a control strategy will be set within the processing module. Based on this control strategy, one of the first and third phase transistor groups and the second and third phase transistor groups will be repeatedly switched on while the other is switched off. For example, the control strategy includes a periodic time; at regular intervals, the first and third phase transistor groups will be switched on, and at regular intervals, the second and third phase transistor groups will be switched on.

[0064] Based on the above configuration, please refer to Figure 2 This effectively solves the problem of severe IGBT overheating caused by excessive first-cycle current during ASC, and enables balanced heating of various devices in systems with large steady-state ASC current, thus avoiding overheating failure of the motor controller.

[0065] See Figure 3 In a preferred embodiment, the first cycle current in the ASC process can be understood as the first cycle of the current sine wave. Within this cycle, the processing module acquires the magnitudes of the first phase current, the second phase current, and the third phase current, and selects the phase with the largest absolute value as the maximum current phase; when the maximum current value of the maximum current phase is greater than or equal to the safety turn-off threshold, the processing module controls the first three-phase group to turn off, and the control operation of turning on the second three-phase group is recorded as the first switching.

[0066] Preferably or optionally, in one embodiment, the control strategy includes: a preset current zero-crossing threshold in the processing module, wherein the current zero-crossing threshold is greater than 0 and approximately equal to 0, i.e., the current zero-crossing threshold is slightly greater than 0. As the first three-phase group and the second three-phase group switch, the current value of each phase will alternate between positive and negative values ​​in each cycle. Therefore, the role of the current zero-crossing value is that when the absolute value of the current maximum is less than the current zero-crossing threshold, it indicates that the current of the phase with the maximum current is about to cross zero (or after switching, it is close to half a cycle), or when the current maximum is reversed, and the absolute value of the current of the other two phases besides the phase with the maximum current is less than or equal to the safe turn-off threshold, the processing module switches the conduction or turn-off of the first three-phase group and the second three-phase group. The above control strategy indicates that the phase with the maximum current is about to reverse, the current of the other two phases is still within the safe value, and the heat is also balanced in the currently conducting three-phase group, but it cannot continue to share the heat for a long time, and the heat needs to be generated in another three-phase group. Therefore, under this control strategy, the first three-pipe group and the second three-pipe group will be repeatedly turned on.

[0067] Furthermore, the conduction of the first and second three-phase power supply groups will be controlled based on time factors. Specifically, the control strategy includes: a preset time threshold within the processing module; each time the processing module switches the conduction or de-conduction of the first and second three-phase power supply groups, a switching time is started, i.e., when switching from the conduction of the first three-phase power supply group to the conduction of the second three-phase power supply group, the timer starts from zero, and when switching from the conduction of the second three-phase power supply group to the conduction of the first three-phase power supply group, the timer restarts; the processing module switches the conduction or de-conduction of the first and second three-phase power supply groups only when the calculated switching time is greater than or equal to the time threshold, indicating that the conducted first or second three-phase power supply group has absorbed a certain amount of heat, thus avoiding the ping-pong effect of repeatedly switching the conduction of the first or second three-phase power supply group in a very short time. In a further embodiment, the time threshold is less than or equal to 1 / 2 of the sinusoidal period of the current in the three-phase circuit of the motor, so that the edge switching is included in the number of switching cycles in the next cycle, and only two switching cycles occur in each switching cycle.

[0068] See Figure 4 The present invention also discloses a power chip control method, comprising the following steps:

[0069] S100: The motor three-phase circuit is configured as follows: The motor three-phase circuit includes a first phase, a second phase, and a third phase; the first phase includes a first IGBT chip and a second IGBT chip connected in series, wherein the first IGBT chip includes a first switching transistor and a first diode connected in parallel, and the second IGBT chip includes a second switching transistor and a second diode connected in parallel; the second phase includes a third IGBT chip and a fourth IGBT chip connected in series, wherein the third IGBT chip includes a third switching transistor and a third diode connected in parallel, and the fourth IGBT chip includes a fourth switching transistor and a fourth diode connected in parallel; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series, wherein the fifth IGBT chip includes a fifth switching transistor and a fifth diode connected in parallel, and the sixth IGBT chip includes a sixth switching transistor and a sixth diode connected in parallel.

[0070] S200: When a vehicle drive system with a power chip malfunctions, causing the power chip to enter the ASC state, a processing module controls the first three-transistor group composed of the first, third, and fifth switching transistors to turn on, and the second three-transistor group composed of the second, fourth, and sixth switching transistors to turn off, and calculates the first phase current of the first phase, the second phase current of the second phase, and the third phase current of the third phase.

[0071] S300: The processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the phase with the maximum current value. When the maximum current value is greater than or equal to the preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on.

[0072] S400: The processing module also continuously monitors the first phase current, the second phase current, and the third phase current, and repeatedly switches one of the first three-transistor group and the second three-transistor group to be on and the other to be off based on a preset control strategy.

[0073] Preferably, the processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the maximum current phase, and when the maximum current value is greater than or equal to a preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on, the step S300 includes:

[0074] S310: The processing module obtains the magnitudes of the first phase current, the second phase current, and the third phase current, and selects the phase with the largest absolute value as the phase with the largest current.

[0075] S320: When the maximum current of the phase with the maximum current is greater than or equal to the safety shutdown threshold, the processing module controls the first three-transistor group to turn off and the second three-transistor group to turn on. This control operation is recorded as the first switch.

[0076] Preferably, the control strategy includes:

[0077] The processing module has a preset current zero-crossing threshold, which is greater than 0 and approximately equal to 0.

[0078] When the absolute value of the maximum current is less than the current zero-crossing threshold, or the maximum current is in reverse phase, and the absolute values ​​of the currents in the other two phases besides the phase with the maximum current are less than or equal to the safety turn-off threshold, the processing module switches the first three-phase group and the second three-phase group to be turned on or off.

[0079] Preferably, the control strategy further includes:

[0080] The processing module has a preset time threshold;

[0081] Each time the processing module switches the first three-tube group and the second three-tube group on or off, it starts timing for one switching time.

[0082] The processing module switches the first three-tube group and the second three-tube group on or off only when the switching time is greater than or equal to the time threshold.

[0083] Preferably, the time threshold is less than or equal to 1 / 2 of the sinusoidal period of the current in the three-phase circuit of the motor.

[0084] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A power chip control system, characterized in that, The power chip control system includes a three-phase motor circuit and a processing module; A three-phase circuit for a motor includes the first phase, the second phase, and the third phase. The first phase includes a first IGBT chip and a second IGBT chip connected in series, wherein the first IGBT chip includes a first switching transistor and a first diode connected in parallel, and the second IGBT chip includes a second switching transistor and a second diode connected in parallel. The second phase includes a third IGBT chip and a fourth IGBT chip connected in series, wherein the third IGBT chip includes a third switch and a third diode connected in parallel, and the fourth IGBT chip includes a fourth switch and a fourth diode connected in parallel. The third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series, wherein the fifth IGBT chip includes a fifth switch and a fifth diode connected in parallel, and the sixth IGBT chip includes a sixth switch and a sixth diode connected in parallel. When a vehicle drive system with a power chip malfunctions, causing the power chip to enter the ASC state, the processing module controls the first three-transistor group composed of the first, third, and fifth switches to turn on, and the second three-transistor group composed of the second, fourth, and sixth switches to turn off, and calculates the first phase current of the first phase, the second phase current of the second phase, and the third phase current of the third phase. The processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the phase with the maximum current value, and when the maximum current value is greater than or equal to the preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on. The processing module also continuously monitors the first phase current, the second phase current, and the third phase current, and repeatedly switches one of the first three-transistor group and the second three-transistor group to be on and the other to be off based on a preset control strategy. The control strategy includes: The processing module has a preset current zero-crossing threshold, wherein the current zero-crossing threshold is greater than 0 and approximately equal to 0. When the absolute value of the maximum current is less than the current zero-crossing threshold, or the maximum current is out of phase, and the absolute values ​​of the currents of the other two phases besides the maximum current phase are less than or equal to the safety shutdown threshold, the processing module switches the first three-tube group and the second three-tube group to be turned on or off. The control strategy also includes: The processing module has a preset time threshold. Each time the processing module switches the first three-tube group and the second three-tube group on or off, it starts timing the switching time. The processing module switches the first three-tube group and the second three-tube group on or off only when the switching time is greater than or equal to the time threshold. The time threshold is less than or equal to half of the sinusoidal period of the current in the three-phase circuit of the motor.

2. The power chip control system as described in claim 1, characterized in that, The processing module obtains the magnitudes of the first phase current, the second phase current, and the third phase current, and selects the phase with the largest absolute value as the phase with the largest current. When the maximum current value of the phase with the maximum current is greater than or equal to the safety shutdown threshold, the processing module controls the first three-transistor group to turn off, and the control operation of turning on the second three-transistor group is recorded as the first switching.

3. A power chip control method, characterized in that, Includes the following steps: The motor three-phase circuit is configured as follows: The motor three-phase circuit includes a first phase, a second phase, and a third phase; the first phase includes a first IGBT chip and a second IGBT chip connected in series, wherein the first IGBT chip includes a first switching transistor and a first diode connected in parallel, and the second IGBT chip includes a second switching transistor and a second diode connected in parallel; the second phase includes a third IGBT chip and a fourth IGBT chip connected in series, wherein the third IGBT chip includes a third switching transistor and a third diode connected in parallel, and the fourth IGBT chip includes a fourth switching transistor and a fourth diode connected in parallel; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected in series, wherein the fifth IGBT chip includes a fifth switching transistor and a fifth diode connected in parallel, and the sixth IGBT chip includes a sixth switching transistor and a sixth diode connected in parallel; When a vehicle drive system with a power chip malfunctions, causing the power chip to enter the ASC state, a processing module controls the first three-transistor group composed of the first, third, and fifth switches to turn on, and the second three-transistor group composed of the second, fourth, and sixth switches to turn off, and calculates the first phase current of the first phase, the second phase current of the second phase, and the third phase current of the third phase. The processing module selects the phase with the maximum current value among the first phase current, the second phase current, and the third phase current as the phase with the maximum current value, and when the maximum current value is greater than or equal to the preset safety shutdown threshold, the processing module controls the first three-phase group to turn off and the second three-phase group to turn on. The processing module also continuously monitors the first phase current, the second phase current, and the third phase current, and repeatedly switches one of the first three-transistor group and the second three-transistor group to be on and the other to be off based on a preset control strategy. The control strategy includes: The processing module has a preset current zero-crossing threshold, wherein the current zero-crossing threshold is greater than 0 and approximately equal to 0. When the absolute value of the maximum current is less than the current zero-crossing threshold, or the maximum current is out of phase, and the absolute values ​​of the currents of the other two phases besides the maximum current phase are less than or equal to the safety shutdown threshold, the processing module switches the first three-tube group and the second three-tube group to be turned on or off. The control strategy also includes: The processing module has a preset time threshold. Each time the processing module switches the first three-tube group and the second three-tube group on or off, it starts timing the switching time. The processing module switches the first three-tube group and the second three-tube group on or off only when the switching time is greater than or equal to the time threshold. The time threshold is less than or equal to half of the sinusoidal period of the current in the three-phase circuit of the motor.

4. The power chip control method as described in claim 3, characterized in that, The processing module selects the phase with the maximum current value among the first phase current, second phase current, and third phase current as the maximum current phase, and when the maximum current value is greater than or equal to a preset safety shutdown threshold, the processing module controls the first three-phase group to turn off, and the second three-phase group to turn on includes the following steps: The processing module obtains the magnitudes of the first phase current, the second phase current, and the third phase current, and selects the phase with the largest absolute value as the phase with the largest current. When the maximum current value of the phase with the maximum current is greater than or equal to the safety shutdown threshold, the processing module controls the first three-transistor group to turn off, and the control operation of turning on the second three-transistor group is recorded as the first switching.

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