Motor controller, vehicle, and discharge method
By designing a bus capacitor discharge method for new energy vehicles in a motor controller, and discharging the bus capacitor using a bridge arm circuit or voltage divider circuit, the problem of residual voltage of the motor controller after the high-voltage relay is disconnected is solved, and the problem of residual voltage of the motor controller is avoided The safety hazards of torque jitter and fault discharge achieve safe and stable motor control.
Patent Information
- Application Number
- CN202411404307.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2024-12-20
AI Technical Summary
The DC bus capacitor of the motor controller of the new energy vehicle is easily damaged by the high-voltage relay after the high-voltage relay is disconnected. The existing technology generates heat and discharges quickly through the motor winding, but will cause torque jitter, affecting the driving experience, and in the event of a fault. It is impossible to discharge under the circumstances, which poses a safety hazard.
Design a motor controller, including bus capacitors, three-phase bridge arm circuits and voltage divider circuits, through the control circuit, selectively discharge the bus capacitors with bridge arm circuits or voltage divider circuits under the high-voltage relay disconnection signal to avoid Use the motor winding to generate heat and discharge to ensure safety and stability of discharge.
It effectively avoids torque jitter, improves driving experience, and ensures the feasibility of discharge when the motor controller fails, solving safety hazards.
Smart Images
Figure CN119171797A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of vehicle technology, and in particular to a motor controller, a vehicle and a discharge method. Background Art
[0002] The DC bus capacitor of the motor controller of new energy vehicles is connected in parallel with the power battery through a high-voltage relay. When the high-voltage relay is disconnected, the high voltage electricity still remaining in the DC bus capacitor can easily damage the power devices of the motor controller. In the relevant technology, the heat generated by the motor winding is usually used to quickly consume the electricity stored in the DC bus capacitor. Although this method has a fast discharge time, torque jitter will occur, affecting the driving experience. In addition, if the motor controller or motor fails, discharge will not be possible, posing a safety hazard. Summary of the invention
[0003] Based on this, it is necessary to provide a new motor controller, vehicle and discharge method that can discharge the bus capacitor in order to solve the above technical problems.
[0004] In a first aspect, the present application provides a motor controller, the motor controller comprising a bus capacitor, a three-phase bridge arm circuit, a voltage divider circuit and a control circuit;
[0005] The bus capacitor is used to be connected in parallel with the battery through a switch circuit;
[0006] The bridge arm circuit of each phase is connected in parallel with the bus capacitor, the output end of the bridge arm circuit of each phase is used to be connected to the corresponding motor winding, and the control end of the bridge arm circuit of each phase is connected to the control circuit;
[0007] The voltage divider circuit is connected in parallel with the bus capacitor, and the output end of the voltage divider circuit is connected with the control circuit;
[0008] In which, the control circuit is used to control the target bridge arm circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit when at least one phase of the bridge arm circuit is normal, and the target bridge arm circuit is one of all normal bridge arm circuits; and is used to control the voltage divider circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit when the bridge arm circuits of each phase fail.
[0009] In one embodiment, the control circuit includes a first power supply and a second power supply, and a voltage of the first power supply is less than a voltage of the second power supply;
[0010] Each phase of the bridge arm circuit comprises a first switch unit and a second switch unit, wherein a first end of the first switch unit is connected to a first end of the bus capacitor, a second end of the first switch unit is connected to a first end of the second switch unit, and a second end of the second switch unit is connected to a second end of the bus capacitor;
[0011] Wherein, when the control circuit controls the target bridge arm circuit to discharge the bus capacitor, the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the first power supply and the control end of the second switch unit to be connected to the second power supply, or controls the control end of the first switch unit of the target bridge arm circuit to be connected to the second power supply and the control end of the second switch unit to be connected to the first power supply.
[0012] In one embodiment, the first switch unit includes a first transistor, and the second switch unit includes a second transistor;
[0013] Wherein, when the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the first power supply and the control end of the second switch unit to be connected to the second power supply, the first transistor operates in the linear amplification region and the second transistor is fully turned on;
[0014] When the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the second power supply and the control end of the second switch unit to be connected to the first power supply, the first transistor is fully turned on and the second transistor operates in the linear amplification region.
[0015] In one of the embodiments, the voltage divider circuit includes a first resistance unit and a second resistance unit;
[0016] The first end of the first resistance unit is connected to the first end of the bus capacitor, the second end of the first resistance unit is connected to the first end of the second resistance unit, and the second end of the second resistance unit is connected to the second end of the bus capacitor, wherein the first end of the second resistance unit serves as the output end of the voltage divider circuit.
[0017] In one of the embodiments, the control circuit is also used to, during the process of controlling the bridge arm circuit to discharge the bus capacitor, determine that the bridge arm circuit is normal if the change in the voltage divider signal output by the voltage divider circuit within a first preset time period meets the discharge requirement, and determine that the bridge arm circuit is faulty if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period does not meet the discharge requirement.
[0018] In one of the embodiments, the control circuit is also used to control the target bridge arm circuit to discharge the bus capacitor for a second preset time period, and if the voltage divider signal output by the voltage divider circuit meets the discharge end requirement, determine that the discharge of the bus capacitor is completed, and control the motor controller to shut down.
[0019] In a second aspect, the present application also provides a vehicle, comprising a motor, a switching circuit and a motor controller as described in the first aspect above.
[0020] In a third aspect, the present application further provides a discharging method, which is performed by the motor controller described in the first aspect, and the method includes:
[0021] When at least one phase of the bridge arm circuit is normal, controlling the target bridge arm circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit, the target bridge arm circuit being one of all the normal bridge arm circuits;
[0022] In the case that the bridge arm circuits of each phase fail, the voltage divider circuit is controlled to discharge the bus capacitor according to the disconnection signal of the switch circuit.
[0023] In one embodiment, the method further comprises:
[0024] In the process of controlling the bridge arm circuit to discharge the bus capacitor, if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period meets the discharge requirement, the bridge arm circuit is determined to be normal; if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period does not meet the discharge requirement, the bridge arm circuit is determined to be faulty.
[0025] In one embodiment, the method further comprises:
[0026] After controlling the target bridge arm circuit to discharge the bus capacitor for a second preset time, if the voltage divider signal output by the voltage divider circuit meets the discharge end requirement, it is determined that the discharge of the bus capacitor is completed, and the motor controller is controlled to shut down.
[0027] The above-mentioned motor controller, vehicle and discharge method, wherein the motor controller includes a bus capacitor, a three-phase bridge arm circuit, a voltage divider circuit and a control circuit, the bus capacitor is a DC bus capacitor, and the bus capacitor is, for example, connected in parallel with the power battery through a high-voltage relay, each phase bridge arm circuit and the voltage divider circuit are connected in parallel with the bus capacitor, the control end of each phase bridge arm circuit and the output end of the voltage divider circuit are connected to the control circuit, and the output end of each phase bridge arm circuit is used to connect with the corresponding motor winding; based on this, when at least one phase bridge arm circuit is normal, the control circuit controls the target bridge arm circuit to discharge the bus capacitor according to the disconnection signal of the high-voltage relay, and the target bridge arm circuit is one of all normal bridge arm circuits, and when all phase bridge arm circuits are faulty, the control circuit controls the voltage divider circuit to discharge the bus capacitor according to the disconnection signal of the high-voltage relay. In this way, the discharge of the bus capacitor is achieved by using the bridge arm circuit or the voltage divider circuit, avoiding the problem of torque jitter caused by the discharge method of motor winding heating, thereby affecting the driving experience, and also solving the problem that the discharge cannot be carried out if the motor controller or the motor fails. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0029] FIG1 is a schematic diagram of a motor controller according to an embodiment of the present invention;
[0030] Figure 2 This is a second structural diagram of a motor controller in one embodiment;
[0031] Figure 3 The third structural diagram of a motor controller in one embodiment;
[0032] Figure 4 This is a fourth structural diagram of a motor controller in one embodiment;
[0033] Figure 5 This is the fifth structural diagram of the motor controller in one embodiment. DETAILED DESCRIPTION
[0034] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0036] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.
[0037] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.
[0038] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.
[0039] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.
[0040] The motor controller provided in the embodiments of the present application can be applied to a vehicle, such as a new energy vehicle.
[0041] In an exemplary embodiment, referring to FIG. 1 , a motor controller is provided. The motor controller includes a bus capacitor 110 , a three-phase bridge arm circuit 120 , a voltage divider circuit 130 , and a control circuit 140 .
[0042] The bus capacitor 110 is used to be connected in parallel with the battery through a switch circuit. The bus capacitor 110 can be understood as a DC bus capacitor 110, the switch circuit can be but not limited to a high-voltage relay, and the battery can be but not limited to a power battery of a new energy vehicle.
[0043] Each phase bridge arm circuit 120 is connected in parallel with the bus capacitor 110, and the output end of each phase bridge arm circuit 120 is used to connect to the corresponding motor winding, and the control end of each phase bridge arm circuit 120 is connected to the control circuit 140. Among them, each phase bridge arm circuit 120 can be composed of at least a plurality of power devices. The three-phase bridge arm circuit 120 is, for example, a three-phase U-phase bridge arm circuit 120, a three-phase V-phase bridge arm circuit 120, and a three-phase W-phase bridge arm circuit 120. The U-phase bridge arm circuit 120 can be connected to the U-phase winding of the motor of the new energy vehicle, the V-phase bridge arm circuit 120 can be connected to the V-phase winding of the motor, and the W-phase bridge arm circuit 120 can be connected to the W-phase bridge arm circuit 120 of the motor.
[0044] The voltage divider circuit 130 is connected in parallel with the bus capacitor 110, and the output end of the voltage divider circuit 130 is connected to the control circuit 140. The voltage divider circuit 130 can be composed of components such as resistors and capacitors. The voltage divider circuit 130 can divide the voltage of the bus capacitor 110 and output the voltage division signal to the control circuit 140, and the control circuit 140 can determine the voltage of the bus capacitor 110 according to the voltage division signal.
[0045] The control circuit 140 may be integrated on a control circuit 140 board. The control circuit 140 is used to control the target bridge arm circuit 120 to discharge the bus capacitor 110 according to the disconnection signal of the switch circuit when at least one phase bridge arm circuit 120 is normal, and the target bridge arm circuit 120 is one of all normal bridge arm circuits 120, and is used to control the voltage divider circuit 130 to discharge the bus capacitor 110 according to the disconnection signal of the switch circuit when all phase bridge arm circuits 120 are faulty.
[0046] Among them, the bridge arm circuit 120 being faulty can be understood as at least one power device of the bridge arm circuit 120 being faulty, and the bridge arm circuit 120 being normal can be understood as each power device of the bridge arm circuit 120 being normal. In the case that a certain phase bridge arm circuit 120 is faulty, since the phase bridge arm circuit 120 cannot form a loop with the motor winding, the phase bridge arm circuit 120 cannot participate in the discharge of the bus capacitor 110 as a target bridge arm circuit 120, and only a normal bridge arm circuit 120 can participate in the discharge of the bus capacitor 110 as a target bridge arm circuit 120.
[0047] The disconnection signal of the switch circuit is, for example, a disconnection signal of a high-voltage relay. The disconnection signal of the high-voltage relay can be sent to the vehicle controller of the new energy vehicle, and the vehicle controller sends a discharge instruction to the control circuit 140 according to the disconnection signal of the high-voltage relay, and the control circuit 140 controls a normal bridge arm circuit 120 to discharge the bus capacitor 110 according to the discharge instruction, or controls the voltage divider circuit 130 to discharge the bus capacitor 110 when all the bridge arm circuits 120 of each phase fail; or, the disconnection signal of the switch circuit is directly output to the control circuit 140, and the control circuit 140 directly controls a normal bridge arm circuit 120 to discharge the bus capacitor 110 according to the disconnection signal, or controls the voltage divider circuit 130 to discharge the bus capacitor 110 when all the bridge arm circuits 120 of each phase fail.
[0048] In the embodiment of the present application, the discharge of the bus capacitor 110 is achieved based on the three-phase bridge arm circuit 120 or the voltage divider circuit 130, avoiding the problem of torque jitter affecting the driving experience due to the discharge method of heating the motor winding, and also solving the problem that the discharge cannot be performed if the motor controller or the motor fails.
[0049] In an exemplary embodiment, referring to Figure 2 , the control circuit 140 includes a first power supply and a second power supply, and the voltage of the first power supply is lower than the voltage of the second power supply.
[0050] Each phase bridge arm circuit 120 includes a first switch unit 121 and a second switch unit 122. The first end of the first switch unit 121 is connected to the first end of the bus capacitor 110, the second end of the first switch unit 121 is connected to the first end of the second switch unit 122, and the second end of the second switch unit 122 is connected to the second end of the bus capacitor 110.
[0051] In which, when the control circuit 140 controls the target bridge arm circuit 120 to discharge the bus capacitor 110, the control circuit 140 controls the control end of the first switch unit 121 of the target bridge arm circuit 120 to be connected to the first power supply and the control end of the second switch unit 122 to be connected to the second power supply, or controls the control end of the first switch unit 121 of the target bridge arm circuit 120 to be connected to the second power supply and the control end of the second switch unit 122 to be connected to the first power supply.
[0052] In this embodiment, the first switch unit 121 may include at least one transistor, wherein the states of the multiple transistors are completely synchronized, and the multiple transistors may be connected in parallel. The second switch unit 122 may include at least one transistor, wherein the states of the multiple transistors are completely synchronized, and the multiple transistors may be connected in parallel.
[0053] Among the first switch unit 121 and the second switch unit 122 of the target bridge arm circuit 120, the control end of one of them is connected to the first power supply, and the control end of the other is connected to the second power supply, and the voltage of the first power supply is less than the voltage of the second power supply. Therefore, when the control circuit 140 controls the target bridge arm circuit 120 to discharge the bus capacitor 110, one of the first switch unit 121 and the second switch unit 122 is fully turned on, and the other works in the linear amplification area, thereby realizing low-current and low-loss discharge of the bus capacitor 110.
[0054] In an exemplary embodiment, referring to Figure 3 The first switch unit 121 includes a first transistor T1, and the second switch unit 122 includes a second transistor T2.
[0055] Among them, when the control circuit 140 controls the control end of the first switch unit 121 of the target bridge arm circuit 120 to be connected to the first power supply and the control end of the second switch unit 122 to be connected to the second power supply, the first transistor T1 operates in the linear amplification area and the second transistor T2 is fully turned on; when the control circuit 140 controls the control end of the first switch unit 121 of the target bridge arm circuit 120 to be connected to the second power supply and the control end of the second switch unit 122 to be connected to the first power supply, the first transistor T1 is fully turned on and the second transistor T2 operates in the linear amplification area.
[0056] In this embodiment, the first transistor T1 and the second transistor T2 are, for example, insulated gate bipolar transistors (IGBTs). The turn-on voltage Vth of the IGBT is generally about +4V, and the turn-on voltage of the IGBT is generally about +15V. In view of this, the voltage of the first power supply is, for example, about +9V, and the voltage of the second power supply is, for example, about +15V. In this way, the collector current of the IGBT of the target bridge arm circuit 120 can be limited to a smaller value, ensuring the safe operation of the IGBT without generating a large amount of heat burnout. In addition, the collector current of the IGBT is small, the loss is small, and the conduction time is extremely short (for example, less than the short-circuit tolerance of the IGBT, generally within 8us), and multiple conductions discharge the high voltage on the DC bus capacitor 110.
[0057] In an exemplary embodiment, referring to Figure 4 The voltage divider circuit 130 includes a first resistor unit 131 and a second resistor unit 132. The first end of the first resistor unit 131 is connected to the first end of the bus capacitor 110, the second end of the first resistor unit 131 is connected to the first end of the second resistor unit 132, and the second end of the second resistor unit 132 is connected to the second end of the bus capacitor 110, wherein the first end of the second resistor unit 132 serves as the output end of the voltage divider circuit 130.
[0058] In this embodiment, the first resistor unit 131 and the second resistor unit 132 can be composed of at least one resistor element. In the case that all phase bridge arm circuits 120 fail, the first resistor unit 131 and the second resistor unit 132 can be connected in series to achieve a longer discharge of the bus capacitor 110, for example, after 5 minutes of static discharge, the high voltage is tested to see if it is discharged to less than 60V.
[0059] In an exemplary embodiment, referring to Figure 5 The voltage divider circuit 130 further includes a filter unit 133 , and the filter unit 133 is connected in parallel with the second resistance unit 132 .
[0060] In this embodiment, the filter unit 133 may be composed of at least one capacitor component. The filter unit 133 can filter the voltage-divided signal, so that the control circuit 140 can more accurately determine the voltage of the bus capacitor 110.
[0061] In an exemplary embodiment, the control circuit 140 is also used to control the bridge arm circuit 120 to discharge the bus capacitor 110. If the change in the voltage divider signal output by the voltage divider circuit 130 within a first preset time period meets the preset discharge requirement, the bridge arm circuit 120 is determined to be normal; if the change in the voltage divider signal output by the voltage divider circuit 130 within the first preset time period does not meet the preset discharge requirement, the bridge arm circuit 120 is determined to be faulty.
[0062] In this embodiment, the preset discharge requirement is, for example, that the change in the reduction of the voltage of the bus capacitor 110 within the first preset time length reaches a preset threshold value, for example, the voltage of the bus capacitor 110 drops from about 500V to less than 300V within 0.5s, then it is determined that the preset discharge requirement is met. In other words, when the bus capacitor 110 needs to be discharged, the control circuit 140 randomly controls one of the three-phase bridge arm circuits 120 to discharge, and after 0.5s of discharge, it is determined based on the voltage divider signal output by the voltage divider circuit 130 whether the voltage of the bus capacitor 110 drops from about 500V to less than 300V. If so, it is determined that the bridge arm circuit 120 is normal, and the bridge arm circuit 120 continues to discharge. If not, it is determined that the bridge arm circuit 120 is faulty, and it is switched to control another bridge arm circuit 120 for discharge, and it is still determined based on the voltage divider signal output by the voltage divider circuit 130 after 0.5s of discharge that the bus capacitor 110 voltage drops. Whether the voltage drops below 300V, if so, it is determined that the bridge arm circuit 120 is normal and the bridge arm circuit 120 continues to discharge, if not, it is determined that the bridge arm circuit 120 is faulty, and switch to control the remaining bridge arm circuit 120 for discharge, or judge whether the bridge arm circuit 120 meets the discharge requirements according to the voltage division signal, if so, it is determined that the bridge arm circuit 120 is normal and the bridge arm circuit 120 continues to discharge, if not, when all the bridge arm circuits 120 of each phase are faulty, the bus capacitor 110 can be discharged for a longer time by connecting the first resistance unit 131 and the second resistance unit 132 in series.
[0063] In an exemplary embodiment, the control circuit 140 is also used to control the target bridge arm circuit 120 to discharge the bus capacitor 110 for a second preset time period. If the voltage divider signal output by the voltage divider circuit 130 meets the preset discharge end requirement, it is determined that the discharge of the bus capacitor 110 is completed and the motor controller is controlled to shut down.
[0064] In this embodiment, the control circuit 140 may determine that the bridge arm circuit 120 is normal within the first preset time, and use the normal bridge arm circuit 120 to continue discharging for the second preset time. If the voltage division signal output by the voltage division circuit 130 meets the preset discharge end requirement, it is determined that the discharge of the bus capacitor 110 is completed, and the motor controller is controlled to shut down. For example, the control circuit 140 determines that the voltage of the bus capacitor 110 drops from about 500V to less than 300V within 0.5s, then determines that the bridge arm circuit 120 is normal, and continues to discharge with the bridge arm circuit 120. After discharging for 1.5s, it is determined whether the bus capacitor 110 voltage is less than 60V according to the voltage division signal. If so, it is determined that the discharge of the bus capacitor 110 is completed, and the motor controller is controlled to shut down. In this way, the voltage of the bus capacitor 110 is discharged from a high voltage of about 500V to less than 60V in just 2s.
[0065] In an exemplary embodiment, a vehicle is also provided. The vehicle may be, but is not limited to, a new energy vehicle. The vehicle includes a motor, a switching circuit, and a motor controller as provided in any of the above embodiments.
[0066] The vehicle and the motor controller provided in the embodiments of the present application belong to the same inventive concept, can solve the same technical problems, and thus achieve the same technical effects, and the repeated contents will not be repeated here.
[0067] In an exemplary embodiment, a discharging method is further provided. The discharging method may be executed by a motor controller provided in any of the above embodiments. The discharging method includes:
[0068] When at least one phase bridge arm circuit 120 is normal, the target bridge arm circuit 120 is controlled to discharge the bus capacitor 110 according to the disconnection signal of the switch circuit, and the target bridge arm circuit 120 is one of all normal bridge arm circuits 120;
[0069] When all the bridge arm circuits 120 of each phase fail, the voltage divider circuit 130 is controlled to discharge the bus capacitor 110 according to the disconnection signal of the switch circuit.
[0070] The motor controller and the discharge method provided in the embodiments of the present application both belong to the same inventive concept, can solve the same technical problems, and thus achieve the same technical effects, and the repeated contents will not be repeated here.
[0071] In an exemplary embodiment, the discharge method also includes: in the process of controlling the bridge arm circuit 120 to discharge the bus capacitor 110, if the change amount of the voltage divider signal output by the voltage divider circuit 130 within the first preset time length meets the preset discharge requirement, the bridge arm circuit 120 is determined to be normal; if the change amount of the voltage divider signal output by the voltage divider circuit 130 within the first preset time length does not meet the preset discharge requirement, the bridge arm circuit 120 is determined to be faulty.
[0072] In an exemplary embodiment, the discharge method also includes: after controlling the target bridge arm circuit 120 to discharge the bus capacitor 110 for a second preset time period, if the voltage divider signal output by the voltage divider circuit 130 meets the preset discharge end requirement, it is determined that the discharge of the bus capacitor 110 is completed, and the motor controller is controlled to shut down.
[0073] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.
[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.
[0075] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.
Claims
1. A motor controller, characterized in that: The motor controller includes a bus capacitor, a three-phase bridge arm circuit, a voltage divider circuit and a control circuit; The bus capacitor is used to be connected in parallel with the battery through a switch circuit; The bridge arm circuit of each phase is connected in parallel with the bus capacitor, the output end of the bridge arm circuit of each phase is used to be connected to the corresponding motor winding, and the control end of the bridge arm circuit of each phase is connected to the control circuit; The voltage divider circuit is connected in parallel with the bus capacitor, and the output end of the voltage divider circuit is connected with the control circuit; In which, the control circuit is used to control the target bridge arm circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit when at least one phase of the bridge arm circuit is normal, and the target bridge arm circuit is one of all normal bridge arm circuits; and is used to control the voltage divider circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit when the bridge arm circuits of each phase fail.
2. The motor controller according to claim 1, characterized in that: The control circuit includes a first power supply and a second power supply, wherein the voltage of the first power supply is lower than the voltage of the second power supply; Each phase of the bridge arm circuit comprises a first switch unit and a second switch unit, wherein a first end of the first switch unit is connected to a first end of the bus capacitor, a second end of the first switch unit is connected to a first end of the second switch unit, and a second end of the second switch unit is connected to a second end of the bus capacitor; Wherein, when the control circuit controls the target bridge arm circuit to discharge the bus capacitor, the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the first power supply and the control end of the second switch unit to be connected to the second power supply, or controls the control end of the first switch unit of the target bridge arm circuit to be connected to the second power supply and the control end of the second switch unit to be connected to the first power supply.
3. The motor controller according to claim 2, characterized in that: The first switch unit includes a first transistor, and the second switch unit includes a second transistor; Wherein, when the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the first power supply and the control end of the second switch unit to be connected to the second power supply, the first transistor operates in the linear amplification region and the second transistor is fully turned on; When the control circuit controls the control end of the first switch unit of the target bridge arm circuit to be connected to the second power supply and the control end of the second switch unit to be connected to the first power supply, the first transistor is fully turned on and the second transistor operates in the linear amplification region.
4. The motor controller according to claim 1, characterized in that: The voltage divider circuit includes a first resistance unit and a second resistance unit; The first end of the first resistance unit is connected to the first end of the bus capacitor, the second end of the first resistance unit is connected to the first end of the second resistance unit, and the second end of the second resistance unit is connected to the second end of the bus capacitor, wherein the first end of the second resistance unit serves as the output end of the voltage divider circuit.
5. The motor controller according to any one of claims 1 to 4, characterized in that: The control circuit is also used to, during the process of controlling the bridge arm circuit to discharge the bus capacitor, determine that the bridge arm circuit is normal if the change in the voltage divider signal output by the voltage divider circuit within a first preset time period meets the preset discharge requirement, and determine that the bridge arm circuit is faulty if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period does not meet the preset discharge requirement.
6. The motor controller according to any one of claims 1 to 4, characterized in that: The control circuit is also used to control the target bridge arm circuit to discharge the bus capacitor for a second preset time period, and if the voltage divider signal output by the voltage divider circuit meets the preset discharge end requirement, determine that the discharge of the bus capacitor is completed and control the motor controller to shut down.
7. A vehicle, characterized in that: The invention comprises a battery, a motor, a switching circuit and a motor controller as claimed in any one of claims 1 to 6.
8. A discharge method, characterized in that: The method is performed by the motor controller according to any one of claims 1 to 6, and comprises: When at least one phase of the bridge arm circuit is normal, controlling the target bridge arm circuit to discharge the bus capacitor according to the disconnection signal of the switch circuit, the target bridge arm circuit being one of all the normal bridge arm circuits; In the case that the bridge arm circuits of each phase fail, the voltage divider circuit is controlled to discharge the bus capacitor according to the disconnection signal of the switch circuit.
9. The discharge method according to claim 8, characterized in that: The method further comprises: In the process of controlling the bridge arm circuit to discharge the bus capacitor, if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period meets the preset discharge requirement, the bridge arm circuit is determined to be normal; if the change in the voltage divider signal output by the voltage divider circuit within the first preset time period does not meet the preset discharge requirement, the bridge arm circuit is determined to be faulty.
10. The discharge method according to claim 8, characterized in that: The method further comprises: After controlling the target bridge arm circuit to discharge the bus capacitor for a second preset time period, if the voltage divider signal output by the voltage divider circuit meets the preset discharge end requirement, it is determined that the discharge of the bus capacitor is completed, and the motor controller is controlled to shut down.