Discharging method, discharging device and controller

Abstract

The invention relates to the technical field of new energy automobiles, and discloses a discharging method, a discharging device and a controller. The method is applied to the electric drive system, the electric drive system at least comprises a controller, a motor winding and a target resistor, and the method is executed by the controller and comprises the steps that a discharge trigger signal is received; judging whether the vehicle collides or not according to the discharge trigger signal to obtain a judgment result; and controlling the direct-current bus voltage to be discharged through the motor winding and / or the target resistor according to the judgment result. As the target resistor is additionally arranged in the electric driving system, and the direct current bus voltage is discharged by adopting the motor winding and / or the target resistor according to whether the collision occurs, compared with the prior art, even if the motor is damaged and the motor winding cannot be used, the target resistor can still be adopted to discharge the direct current bus voltage, and the reliability of the electric driving system is improved. Reliable discharge of the direct current bus voltage is achieved, and potential safety hazards are effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicle technology, and in particular to a discharge method, a discharge device and a controller. Background Art

[0002] As the ownership rate of new energy vehicles gradually increases, new energy vehicles have become an important part of people's commuting. In new energy vehicles, high voltage safety is directly related to the personal safety of the entire vehicle. Under certain working conditions, such as collision, there may be a risk of high voltage exposure. For the electric drive system of new energy vehicles, the DC bus capacitor is a device directly related to high voltage. Therefore, how to ensure that the DC bus voltage in the DC bus capacitor is reliably discharged under various working conditions is crucial.

[0003] At present, the DC bus voltage of the electric drive system is usually discharged through the motor winding. However, in the event of a collision, if the motor is damaged, the motor winding will not be able to reliably discharge the DC bus high voltage, resulting in a safety hazard. Summary of the invention

[0004] The main purpose of the present application is to provide a discharge method, a discharge device and a controller, aiming to solve the technical problem that the prior art cannot reliably discharge the high voltage of the DC bus and has potential safety hazards.

[0005] To achieve the above object, the present application provides a discharging method, which is applied to an electric drive system, wherein the electric drive system at least includes a controller, a motor winding, and a target resistance. The method is executed by the controller, and includes:

[0006] receiving a discharge trigger signal;

[0007] Determine whether the vehicle has collided according to the discharge trigger signal, and obtain a determination result;

[0008] The DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the judgment result.

[0009] In one embodiment, the step of determining whether the vehicle has collided according to the discharge trigger signal and obtaining a determination result includes:

[0010] Determine whether the vehicle has collided according to whether the discharge trigger signal is a hard-line state signal triggered by a collision event, and obtain a determination result;

[0011] The step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the judgment result includes:

[0012] When the vehicle does not collide, controlling the DC bus voltage to discharge through the motor winding and / or the target resistor according to the state of the main relay;

[0013] When the vehicle collides, the DC bus voltage is controlled to be discharged through the target resistor.

[0014] In one embodiment, when the vehicle does not collide, the step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the state of the main relay includes:

[0015] When the vehicle does not collide, determining whether to trigger an active discharge request;

[0016] When the active discharge request is triggered and the active discharge request verification is passed, obtaining a state signal of a main relay in the electric drive system;

[0017] When the state signal indicates that the main relay is in a disconnected state, determining a DC bus voltage to be discharged;

[0018] The DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the state of the rotary transformer in the electric drive system.

[0019] In one embodiment, when the state signal indicates that the main relay is in a disconnected state, the step of determining that there is a DC bus voltage that needs to be discharged includes:

[0020] When the state signal indicates that the main relay is in a disconnected state, collecting a first effective voltage signal and a second effective voltage signal at a preset position in the electric drive system;

[0021] Determine whether there is a battery voltage signal fed back by the battery management system;

[0022] If the battery voltage signal exists, determining the DC bus voltage to be discharged according to the battery voltage signal, the first effective voltage signal and the second effective voltage signal;

[0023] If the battery voltage signal does not exist, the DC bus voltage to be discharged is determined according to the first effective voltage signal and the second effective voltage signal.

[0024] In one embodiment, the step of controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the state of the rotary transformer in the electric drive system includes:

[0025] Determining whether the rotary transformer in the electric drive system is in a fault state;

[0026] If the fault state is not present, the DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the current vehicle speed;

[0027] If it is in the fault state, the DC bus voltage is controlled to be discharged through the target resistor.

[0028] In one embodiment, after the step of obtaining the state signal of the main relay in the electric drive system when the active discharge request is triggered and the active discharge request verification passes, the step further includes:

[0029] When the state signal indicates that the main relay is in a closed state, determining a DC bus voltage to be discharged;

[0030] The DC bus voltage is controlled to be discharged through the target resistance within a first preset time period.

[0031] In one embodiment, after the step of controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result, the method further includes:

[0032] During the process of the DC bus voltage being discharged through the motor winding, determining whether the DC bus voltage is lower than a preset reference voltage within a second preset time period;

[0033] If the voltage is lower than the preset reference voltage within the second preset time period, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped;

[0034] If the voltage is not lower than the preset reference voltage within the second preset time period, the remaining DC bus voltage is controlled to be discharged through the target resistor.

[0035] In one embodiment, after the step of controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result, the method further includes:

[0036] During the process of the DC bus voltage being discharged through the target resistor, determining whether the DC bus voltage is lower than a preset reference voltage within a third preset time period;

[0037] If the voltage is lower than the preset reference voltage within the third preset time period, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped.

[0038] In addition, to achieve the above-mentioned purpose, the present application also proposes a discharge device, which includes:

[0039] A signal receiving module, used for receiving a discharge trigger signal;

[0040] A collision judgment module, used for judging whether the vehicle has collided according to the discharge trigger signal, and obtaining a judgment result;

[0041] The voltage discharge module is used to control the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result.

[0042] In addition, to achieve the above objectives, the present application also proposes a controller, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the discharge method described above.

[0043] One or more technical solutions proposed in this application have at least the following technical effects:

[0044] The present application is applied to an electric drive system, which includes at least a controller, a motor winding, and a target resistor, and receives a discharge trigger signal; determines whether a vehicle has collided according to the discharge trigger signal to obtain a judgment result; and controls the DC bus voltage to be discharged through the motor winding and / or the target resistor according to the judgment result. Since the present application additionally sets a target resistor in the electric drive system, the DC bus voltage is discharged using the motor winding and / or the target resistor according to whether a collision has occurred. Therefore, compared with the prior art, the present application can still use the target resistor to discharge the DC bus voltage when the motor is damaged and the motor winding cannot be used, thereby achieving reliable discharge of the DC bus voltage and effectively reducing safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] Figure 1 This is a flow chart of the first embodiment of the discharge method of the present application;

[0048] Figure 2 This is a schematic diagram of a motor drive circuit in the electric drive system of this application;

[0049] Figure 3 This is a flow chart of the second embodiment of the discharge method of the present application;

[0050] Figure 4This is a brief schematic diagram of the process of DC bus voltage discharge in the second embodiment of the present application;

[0051] Figure 5 This is a flow chart of the third embodiment of the discharge method of the present application;

[0052] Figure 6 This is a brief flow chart of discharge monitoring in the third embodiment of the present application;

[0053] Figure 7 This is a schematic diagram of the module structure of the discharge device of this application;

[0054] Figure 8 Schematic diagram of the device structure of the hardware operating environment involved in the discharge method in the embodiment of the present application.

[0055] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0056] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0057] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0058] The main solution of the embodiment of the present application is: the controller in the electric drive system receives a discharge trigger signal; determines whether the vehicle has collided according to the discharge trigger signal to obtain a judgment result; and controls the DC bus voltage to discharge through the motor winding and / or the target resistor according to the judgment result.

[0059] Since the prior art generally discharges the DC bus voltage using motor windings, in the event of a collision, if the motor is damaged, the motor windings may not be able to reliably discharge the DC bus high voltage, resulting in a safety hazard.

[0060] The present application provides a solution, in which a target resistor is additionally set in the electric drive system, and the DC bus voltage is discharged using the motor winding and / or the target resistor according to whether a collision occurs. Therefore, compared with the prior art, the present application can still use the target resistor to discharge the DC bus voltage when the motor is damaged and the motor winding cannot be used, thereby achieving reliable discharge of the DC bus voltage and effectively reducing safety hazards.

[0061] Based on this, the present application embodiment provides a discharge method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the discharge method of the present application.

[0062] In this embodiment, the discharge method is applied to an electric drive system, the electric drive system at least includes a controller, a motor winding, and a target resistance, the discharge method is executed by the controller, and the discharge method includes:

[0063] Step S10, receiving a discharge trigger signal.

[0064] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication and program running functions in a new energy vehicle or an electric drive system of a new energy vehicle, such as a vehicle controller, a motor controller, an electronic control unit and other controllers, or an electronic device capable of realizing the above functions. The following takes the controller as an example to illustrate this embodiment and the following embodiments.

[0065] It is understandable that the above-mentioned discharge trigger signal may be a driving signal for triggering the discharge of the DC bus voltage.

[0066] It should be noted that the above-mentioned electric drive system can be a system in a new energy vehicle that converts electrical energy into mechanical energy to drive the vehicle.

[0067] In a specific implementation, the above-mentioned discharge trigger signal can be actively triggered by the user through a button in the car, or it can be triggered by relevant devices or systems in the car in response to specific events. For example, when a vehicle collides, the safety system triggers a discharge trigger signal in response to the collision event. It can also be actively triggered by the controller according to the status of related devices, which is not limited in this embodiment.

[0068] Step S20, determining whether the vehicle has collided according to the discharge trigger signal, and obtaining a determination result.

[0069] In a specific implementation, the controller may respond to the discharge trigger signal after receiving the discharge trigger signal, and may determine whether the discharge trigger signal is derived from feedback from a safety system (such as an airbag control unit) to determine whether the vehicle has collided, and obtain a judgment result, that is, the judgment result includes: when the discharge trigger signal is fed back by the safety system, it is determined that the discharge trigger signal is generated after the safety system responds to a collision, and thus it can be determined that the vehicle has collided; on the contrary, when the discharge trigger signal is not fed back by the safety system, it can be determined that the vehicle has not collided.

[0070] Step S30: controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result.

[0071] It should be noted that the reference Figure 2 , Figure 2 This is a schematic diagram of a motor drive circuit in the electric drive system of this application. Figure 2In the embodiment, the motor driving circuit in the electric driving system includes: a power battery D1, a DC capacitor C1, a switch tube Q0, a main relay S1, first to sixth insulated gate bipolar transistors Q1-Q6, and a motor M. The motor winding can be arranged inside the motor M.

[0072] Among them, taking the NMOS tube as an example of the switch tube, the positive electrode of the power battery D1 is connected to the first end of the main relay S1, the second end of the main relay S2 is respectively connected to the first end of the DC capacitor C1, the drain of the switch tube Q0, the input end of the first insulated gate bipolar transistor Q1, the input end of the second insulated gate bipolar transistor Q2 and the input end of the third insulated gate bipolar transistor Q3, the negative electrode of the power battery D1 is respectively connected to the second end of the DC capacitor C1, the first end of the target resistor R1, the output end of the fourth insulated gate bipolar transistor Q4, the output end of the fifth insulated gate bipolar transistor Q5 and the output end of the sixth insulated gate bipolar transistor Q6, the second end of the target resistor R1 is connected to the source of the switch tube Q0, and the gate of the switch tube Q0 is connected to the controller.

[0073] Figure 2 The motor drive circuit is shown as an example and is not intended to limit the present solution.

[0074] In the specific implementation, Figure 2 To illustrate, when the controller determines that the vehicle has collided according to the discharge trigger signal, it can control the switch tube Q0 to close, connect the loop between the DC capacitor C1 and the target resistor R1, and discharge the DC bus voltage of the DC capacitor C1 through the target resistor R1; when the controller determines that the vehicle has not collided according to the discharge trigger signal, if it receives an active discharge request triggered by the user, it can control the switch tube Q0 to open, connect the loop between the DC capacitor C1 and the motor winding, and discharge the DC bus voltage of the DC capacitor C1 through the motor winding.

[0075] This embodiment is applied to an electric drive system, which includes at least a controller, a motor winding, and a target resistor, and receives a discharge trigger signal; determines whether the vehicle has collided according to the discharge trigger signal to obtain a judgment result; and controls the DC bus voltage to be discharged through the motor winding and / or the target resistor according to the judgment result. Since the present application additionally sets a target resistor in the electric drive system, the DC bus voltage is discharged using the motor winding and / or the target resistor according to whether a collision has occurred. Therefore, compared with the prior art, in the case where the motor is damaged and the motor winding cannot be used, the target resistor can still be used to discharge the DC bus voltage in this embodiment, thereby achieving reliable discharge of the DC bus voltage and effectively reducing safety hazards.

[0076] Based on the first embodiment of the present application, the second embodiment of the present application is proposed. In the second embodiment of the present application, the same or similar contents as those of the first embodiment can be referred to the above introduction, and will not be repeated later. Figure 3 , Figure 3 This is a flow chart of the second embodiment of the discharge method of the present application.

[0077] In this embodiment, step S20 may include:

[0078] Step S21, judging whether the vehicle has collided according to whether the discharge trigger signal is a hard-line state signal triggered by a collision event, and obtaining a judgment result.

[0079] It should be noted that the hard-line status signal may be a signal indicating whether a collision occurs with the vehicle.

[0080] In a specific implementation, when a vehicle collides, the collision sensor detects the impact force in response to the collision event and transmits the signal to the safety system via a hard line. After receiving the signal, the safety system determines whether the impact has reached a preset threshold. If the threshold is reached, the collision event is confirmed to have occurred, and a discharge trigger signal is fed back to the controller via a hard line. At this time, the discharge trigger signal can be a hard line status signal triggered by the collision event, and the controller can determine that the vehicle has collided based on the discharge trigger signal. On the contrary, when the vehicle has not collided, the waveform of the discharge trigger signal received by the controller will be different from the hard line status signal triggered by the collision event, and it is determined that the vehicle has not collided.

[0081] Step S30 may include:

[0082] Step S31, when the vehicle does not collide, controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the state of the main relay.

[0083] In the specific implementation, refer to Figure 2 When the controller detects that the vehicle has not collided, if the main relay is not disconnected, the power battery and the DC capacitor are in a connected state. The power battery provides continuous power for the electric drive system. If the bus voltage is discharged at this time, it may cause the voltage of the electric drive system to drop suddenly, affecting the normal operation of the motor. Based on this, the above-mentioned controller detects the state of the main relay when the vehicle has not collided. When the main relay is in a disconnected state, if the user has a discharge demand and triggers an active discharge request, the circuit between the DC capacitor and the motor winding can be connected, and the DC bus voltage of the DC capacitor is discharged through the motor winding. If the user has no discharge demand and does not trigger an active discharge request, the DC bus voltage of the DC bus will not be discharged to ensure the normal operation of the motor.

[0084] In addition, when the main relay is in a closed state, if the user has a discharge demand, an active discharge request is triggered. At this time, the DC bus voltage includes the voltage output by the power battery, which is relatively large, and the discharge efficiency of the motor winding is low. In order to meet the user's discharge needs, the switch tube can be controlled to close, and the loop between the target resistor and the DC capacitor is turned on. The DC bus voltage of the DC capacitor is discharged by the target resistor, and it can be discharged multiple times to improve the DC bus voltage discharge efficiency.

[0085] Step S32, when the vehicle collides, controlling the DC bus voltage to be discharged through the target resistor.

[0086] In a specific implementation, when a vehicle collides, the above-mentioned controller may cause abnormalities in the motor winding (such as winding insulation damage, etc.), resulting in excessive current or winding overheating, thereby causing more serious electrical failures. To ensure the safety of the entire vehicle, the switch tube can be controlled to close, turning on the loop between the target resistor and the DC capacitor, and the DC bus voltage of the DC capacitor is discharged by the target resistor.

[0087] In a feasible implementation, step S31 may include:

[0088] Step S311, when the vehicle does not collide, determining whether an active discharge request is triggered.

[0089] It should be noted that the above active discharge request may be a request actively triggered by the user through a corresponding button of the vehicle.

[0090] In the specific implementation, when the vehicle has not collided, if the user has a discharge demand, such as switching from a normal operating state (including driving, idling, etc.) to a completely power-off state, an active discharge request can be triggered to the controller through the corresponding button to ensure that the vehicle stops running safely and stably.

[0091] Step S312: when the active discharge request is triggered and the active discharge request verification is passed, a state signal of a main relay in the electric drive system is obtained.

[0092] It should be noted that the above-mentioned state signal may be a signal representing the opening and closing state of the main relay, and the opening and closing state of the main relay includes an open state and a closed state.

[0093] In a specific implementation, when the controller detects the presence of an active discharge request, in order to ensure that the correct active discharge request is received, the active discharge request may be verified, and the verification may be to detect whether the end-to-end (E2E) status of the active discharge request is successful. That is, the controller may detect whether the active discharge request is tampered with or lost during the transmission process. If it is not tampered with or lost, the E2E status is determined to be successful, and then the active discharge request is determined to be successfully received. The active discharge request may be responded to, and the subsequent discharge operation of the DC bus voltage may be performed. On the contrary, when the E2E status fails, it is determined that the received active discharge request is incorrect, and the active discharge request is not responded to at this time, and the active discharge request communication failure may be reported.

[0094] Furthermore, when the active discharge request is triggered and the active discharge request verification is passed, the controller can respond to the active discharge request and obtain a status signal representing the opening and closing state of the main relay from the electric drive system. The status signal of the main relay can be distinguished by high and low levels. For example, the controller can collect a voltage signal at one end of the main relay as the status signal. When the status signal is at a high level, the main relay is determined to be in an open state. When the status signal is at a low level, the main relay is determined to be in a closed state.

[0095] In addition, when the received status signal indicates that the main relay is in a disconnected state, in order to ensure that the status signal is correct, the status signal of the main relay can be checked to detect whether the E2E state of the status signal is successful. When the E2E state of the status signal is successful, the state of the main relay is determined to be disconnected; on the contrary, when the E2E state of the status signal is failed, it is determined that the correct status signal has not been received. Since the main relay is in a closed state when the vehicle is driving normally, at this time, it can be determined that the main relay is still in a closed state.

[0096] Step S313: when the state signal indicates that the main relay is in the disconnected state, determine the DC bus voltage to be discharged.

[0097] In a specific implementation, when the state signal indicates that the main relay is in the disconnected state, the controller can further determine whether there is a DC bus voltage that needs to be discharged, so as to ensure that there is an available DC bus voltage that needs to be discharged at this time.

[0098] In a feasible implementation, step S313 may include:

[0099] Step S3131, when the state signal indicates that the main relay is in a disconnected state, collecting a first effective voltage signal and a second effective voltage signal at a preset position in the electric drive system.

[0100] It should be noted that the above-mentioned preset position may be a position preset in the motor drive circuit of the electric drive system.

[0101] In the specific implementation, Figure 2 As shown, this embodiment uses the first end of the third insulated gate bipolar transistor Q3 and the second end of the sixth insulated gate bipolar transistor Q6 as an example of the preset position, but does not limit this solution. When the state signal indicates that the main relay is in the disconnected state, the controller can collect the voltage signal at the first end of the third insulated gate bipolar transistor Q3 as the first voltage signal, collect the voltage signal at the second end of the sixth insulated gate bipolar transistor Q6 as the second voltage signal, and then verify the first voltage signal and the second voltage signal to detect whether the E2E status of both is successful. When the E2E status of the first voltage signal is successful, the first voltage signal is used as the first valid voltage signal, and when the E2E status of the second voltage signal is successful, the second voltage signal is used as the second valid voltage signal.

[0102] Step S3132, determining whether there is a battery voltage signal fed back by the battery management system.

[0103] In a specific implementation, the battery management system can monitor the battery voltage signal of the power battery in real time, and the controller can determine whether the battery voltage signal fed back by the battery management system is received.

[0104] Step S3133: if the battery voltage signal exists, determining the DC bus voltage to be discharged according to the battery voltage signal, the first effective voltage signal and the second effective voltage signal.

[0105] In a specific implementation, when the above-mentioned controller and the battery management system communicate normally, the battery voltage signal fed back by the battery management system can be received. At this time, the controller can respectively calculate the voltage deviation between the battery voltage signal and the first effective voltage signal, the voltage deviation between the battery voltage signal and the second effective voltage signal, and the voltage deviation between the first effective voltage signal and the second effective voltage signal; if any voltage signal among the battery voltage signal, the first effective voltage signal and the second effective voltage signal has the smallest deviation, it can be determined that the voltage corresponding to the voltage signal is the DC bus voltage required to be discharged.

[0106] Step S3134: if the battery voltage signal does not exist, determining the DC bus voltage to be discharged according to the first effective voltage signal and the second effective voltage signal.

[0107] In a specific implementation, when the communication between the above-mentioned controller and the battery management system is abnormal and the battery voltage signal fed back by the battery management system cannot be received, the voltage corresponding to any voltage signal can be randomly selected from the first effective voltage signal and the second effective voltage signal as the DC bus voltage to be discharged.

[0108] In addition, if the E2E status of one of the first and second voltage signals collected is failure, then when there is no battery voltage signal, the voltage corresponding to the voltage signal with a successful E2E status is used as the DC bus voltage to be discharged, and when there is a battery voltage signal, the voltage corresponding to the battery voltage signal is used as the DC bus voltage to be discharged; if the E2E status of both the first and second voltage signals collected are failures, then when there is no battery voltage signal, it is determined that there is no DC bus voltage to be discharged at present, and when there is a battery voltage signal, the battery voltage signal is used as the DC bus voltage to be discharged, so that it is possible to accurately determine whether there is a DC bus voltage to be discharged at present in the above manner, thereby effectively improving the discharge accuracy of the DC bus voltage.

[0109] It should be understood that after determining the DC bus voltage, the DC bus voltage can be compared with a set threshold value. When it is greater than the threshold value, it is determined that the DC bus voltage is large and needs to be discharged. On the contrary, when it is less than the threshold value, it is determined that the DC bus voltage is small and does not need to be discharged, that is, there is no DC bus voltage that needs to be discharged.

[0110] Step S314: controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the state of the rotary transformer in the electric drive system.

[0111] In a specific implementation, the resolver is used to measure the position and speed of the motor rotor to control the speed and direction of the motor. When the resolver fails, the speed and position information of the motor cannot be accurately obtained. If the DC bus voltage is discharged through the motor winding at this time, it may cause discharge failure or generate additional torque risks. Therefore, after determining the DC bus voltage to be discharged, the above-mentioned controller can determine the state of the resolver. When the resolver is not in a faulty state, the DC bus voltage can be controlled to be discharged through the motor winding. When the resolver is in a faulty state, the DC bus voltage can be controlled to be discharged through the target resistor to ensure that the DC bus voltage can be accurately discharged to ensure the safety of the entire vehicle.

[0112] In a feasible implementation, step S314 may include:

[0113] Step S3141, determining whether the rotary transformer in the electric drive system is in a fault state;

[0114] In a specific implementation, after determining the DC bus voltage that needs to be discharged, the above-mentioned controller can measure the excitation signal of the rotary transformer and check the integrity and stability of the excitation signal. If the excitation signal is lost or abnormal, it can be determined that the rotary transformer is in a fault state. Otherwise, it is determined that the rotary transformer is not in a fault state.

[0115] Step S3142: If the vehicle is not in the fault state, the DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the current vehicle speed.

[0116] In the specific implementation, when the vehicle speed is low, the motor speed is slow, and the efficiency of the motor winding discharge is high, which can quickly reduce the bus voltage and improve the response speed of the system; when the vehicle speed is high, the motor is in a high-speed rotation state, and the motor winding discharge may cause the discharge process to be unstable due to the high speed, and even generate additional torque risks. The target resistor discharge method is carried out through an independent discharge circuit, which is not affected by the motor speed and can ensure safety when driving at high speed. Therefore, when the rotary transformer is not in a faulty state, the above-mentioned controller can select the motor winding or the target resistor to discharge the DC bus voltage according to the current vehicle speed range.

[0117] Furthermore, a vehicle speed threshold can be set. When the controller detects that the current vehicle speed is lower than the vehicle speed threshold, it determines that the vehicle speed is low and controls the DC bus voltage to be discharged through the motor winding; when the controller detects that the current vehicle speed is higher than the vehicle speed threshold, it determines that the vehicle speed is high and controls the DC bus voltage to be discharged through the target resistor.

[0118] Step S3143: If in the fault state, control the DC bus voltage to be discharged through the target resistor.

[0119] In the specific implementation, when the rotary transformer is in a fault state, the state of the motor winding cannot be known. If the motor winding is damaged, the DC bus voltage cannot be discharged. At this time, the controller can control the DC bus voltage to be discharged through the target resistor to accurately discharge the DC bus voltage and ensure the safety of the entire vehicle.

[0120] In a feasible implementation manner, step S312 may further include:

[0121] Step S3121, when the state signal indicates that the main relay is in a closed state, determining a DC bus voltage to be discharged.

[0122] In a specific implementation, when the state signal of the main relay indicates that the main relay is in a closed state, the controller determines the DC bus voltage to be discharged, which can be referred to the above description and will not be repeated here.

[0123] Step S3122: If yes, the DC bus voltage is controlled to be discharged through the target resistor within a first preset time period.

[0124] It should be noted that the first preset time length may be a pre-set time length.

[0125] In a specific implementation, when the controller receives an active discharge request and the main relay is closed, the battery voltage of the power battery is included in the DC bus voltage and cannot be discharged at one time. The DC bus voltage can be controlled to discharge multiple times within the first preset time. Taking 5s as an example of the first preset time, within 5s, the DC bus voltage can be discharged through the target resistance for 2s, then stopped for 1s, and then the DC bus voltage can be discharged through the target resistance for 2s. After 5s, if the DC bus voltage still does not meet the requirements, such as being lower than the set threshold, it can be determined that the DC bus voltage discharge has failed, and the discharge result is fed back.

[0126] For ease of understanding, refer to Figure 4 This is for illustration only, but does not limit this solution. Figure 4 This is a brief schematic diagram of the DC bus voltage discharge process in the second embodiment of the present application. Figure 4 In the process, after the process starts, it is determined whether a collision occurs. If a collision occurs, the target resistor is turned on to discharge when there is an available bus voltage; if no collision occurs, it is determined whether an active discharge request is received. If no active discharge request is received, the discharge operation is not performed; if an active discharge request is received, it is determined whether the main relay is disconnected. If the main relay is not disconnected, the target resistor is turned on to discharge when there is an available bus voltage (that is, there is a DC bus voltage that needs to be discharged). During the discharge process, the discharge can be attempted several times (Thr8 times) within Thr7s (that is, the first preset time); if the main relay is disconnected, it is determined whether the rotary transformer is abnormal. If the rotary transformer is abnormal, the target resistor is turned on to discharge when there is an available bus voltage; if the rotary transformer is not abnormal, it is determined whether the current vehicle speed is less than Thr2 (that is, the vehicle speed threshold). If it is less than Thr2, the handover winding discharge is turned on when there is an available bus voltage. If it is not less than Thr2, the target resistor is turned on to discharge when there is an available bus voltage.

[0127] This embodiment controls the DC bus voltage to be discharged through the target resistor when the vehicle collides; when the vehicle does not collide and an active discharge request is received, the motor winding or the target resistor is selected to discharge the DC bus voltage according to the conditions met by the state of the main relay, the state of the selected transformer, and the current vehicle speed, thereby selecting a suitable discharge to occur, improving the discharge accuracy of the DC bus voltage, and effectively ensuring the safety of the entire vehicle.

[0128] Based on the first and second embodiments of the present application, the third embodiment of the present application is proposed. In the third embodiment of the present application, the same or similar contents as those of the first and second embodiments can be referred to the above introduction, and will not be repeated in the following. Figure 5 , Figure 5 This is a flow chart of the third embodiment of the discharging method of the present application.

[0129] In this embodiment, after step S30, the following steps may also be included:

[0130] Step S41, during the process of the DC bus voltage being discharged through the motor winding, it is determined whether the DC bus voltage is lower than a preset reference voltage within a second preset time period.

[0131] It should be noted that the above-mentioned preset reference voltage can be used as a calibration value to determine whether the DC bus voltage is at a low level and will not affect the safety of the entire vehicle.

[0132] It is understandable that the second preset time length mentioned above can be a preset time length used to determine whether the discharge time length of the motor winding is too long.

[0133] In a specific implementation, a preset reference voltage can be pre-set in the controller. During the process of the above-mentioned controller controlling the DC bus voltage to discharge through the motor winding, the current remaining DC bus voltage can be monitored in real time, and it can be determined whether the remaining DC bus voltage within the second preset time period is lower than the preset reference voltage, so as to confirm whether the discharge is completed.

[0134] Step S42: If the voltage is lower than the preset reference voltage within the second preset time period, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped.

[0135] In a specific implementation, the controller detects that the remaining DC bus voltage is lower than a preset reference voltage within a second preset time period, and determines that the DC bus voltage is discharged successfully. At this time, the DC bus voltage can be stopped from being discharged.

[0136] Step S43: If the voltage is not lower than the preset reference voltage within the second preset time period, the remaining DC bus voltage is controlled to be discharged through the target resistor.

[0137] In a specific implementation, when the controller detects that the remaining DC bus voltage within the second preset time period is not lower than the preset reference voltage, it determines that the motor winding has failed to discharge. In order to improve the discharge efficiency, the switch tube can be turned on, the target resistor is connected to the DC capacitor, and the remaining DC bus voltage is controlled to be discharged through the target resistor.

[0138] Step S44, during the process of the DC bus voltage being discharged through the target resistor, it is determined whether the DC bus voltage is lower than a preset reference voltage within a third preset time period.

[0139] It should be noted that the third preset time length may be used to determine whether the target resistor discharge time length is too long.

[0140] In a specific implementation, during the process of discharging the DC bus voltage through the target resistor, the controller can generate a corresponding third preset time length according to whether the motor winding discharge has been used before the target resistor is turned on, and then monitor the current remaining DC bus voltage in real time, and determine whether the remaining DC bus voltage within the third preset time length is lower than the preset reference voltage, so as to confirm whether the discharge is completed.

[0141] It should be understood that the third preset time length of the target resistor discharge opened after the motor winding discharge fails can be set lower than the third preset time length of the direct discharge through the target resistor. For example, assuming that the second preset time length is T0, the third preset time length of the target resistor discharge opened after the motor winding discharge fails is T1, and the third preset time length of the direct discharge through the target resistor is T2, then T1 = FTTI-T0-Til, T2 = FTTI-Til, where FTTI is the shortest time interval from the occurrence of the internal fault of the relevant item to the possible occurrence of the hazardous event, and Til is the fault reporting period.

[0142] In step S45, if the voltage is lower than the preset reference voltage within the third preset time period, it is determined that the DC bus voltage discharge is successful, and the discharge of the DC bus voltage is stopped.

[0143] In a specific implementation, the controller detects that the remaining DC bus voltage is lower than a preset reference voltage within a third preset time period, and determines that the DC bus voltage is discharged successfully. At this time, the DC bus voltage can be stopped from being discharged.

[0144] For ease of understanding, refer to Figure 6 This is for illustration only, but does not limit this solution. Figure 6 This is a brief schematic diagram of the discharge monitoring process in the third embodiment of the present application. Figure 6After the motor winding discharge is started, the motor winding discharge monitoring is performed to determine whether the DC bus voltage is lower than Thr4V (i.e., the preset reference voltage) within Thr3s. If so, the motor winding discharge is determined to be successful. If not, the target resistor discharge is started. After the target motor discharge is started, the target resistor discharge monitoring is performed. If the motor winding discharge has been performed before the target resistor discharge, it is determined whether the DC bus voltage is less than Thr4V within Thr5s. If so, the target resistor discharge is determined to be successful. If the motor winding discharge has not been performed before the target resistor discharge, it is determined whether the DC bus voltage is less than Thr4V within Thr6s. If so, the target resistor discharge is determined to be successful, wherein Th5<Th6.

[0145] In this embodiment, during the process of the DC bus voltage being discharged through the motor winding, if the DC bus voltage is lower than the preset reference voltage within the second preset time length, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped; if it is not lower than the preset reference voltage within the second preset time length, the remaining DC bus voltage is controlled to be discharged through the target resistor; during the process of the DC bus voltage being discharged through the target resistor, if the DC bus voltage is lower than the preset reference voltage within the third preset time length, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped, thereby realizing the monitoring of excessive discharge, being able to accurately determine whether the excessive discharge is completed, and effectively improving the accuracy of DC bus voltage discharge.

[0146] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the discharge method of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0147] This application also provides a discharge device, please refer to Figure 7 , Figure 7 This is a schematic diagram of the module structure of the discharge device of this application. Figure 7 In the embodiment, the discharge device comprises:

[0148] A signal receiving module 10, used for receiving a discharge trigger signal;

[0149] A collision judgment module 20, used to judge whether the vehicle has collided according to the discharge trigger signal and obtain a judgment result;

[0150] The voltage discharge module 30 is used to control the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result.

[0151] The discharge device provided by the present application adopts the discharge method in the above embodiment, which can solve the technical problem that the DC bus high voltage cannot be discharged reliably and there are safety hazards. Compared with the prior art, the beneficial effects of the discharge device provided by the present application are the same as the beneficial effects of the discharge method provided by the above embodiment, and other technical features in the discharge device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0152] The present application provides a discharge device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the discharge method in the above-mentioned embodiment 1.

[0153] Reference below Figure 8 , Figure 8 Schematic diagram of the device structure of the hardware operating environment involved in the discharge method in the embodiment of the present application. It shows a schematic diagram of the structure of a controller suitable for implementing the embodiment of the present application. The controller in the embodiment of the present application may include but is not limited to devices such as a vehicle controller, a motor controller, an electronic control unit, etc. Figure 8 The controller shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0154] like Figure 8As shown, the controller may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the controller are also stored. The processing device 1001, ROM1002, and RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the controller to communicate with other devices wirelessly or by wire to exchange data. Although the figure shows a controller with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have alternatively.

[0155] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0156] The controller provided by the present application adopts the discharge method in the above embodiment, which can solve the technical problem that the DC bus high voltage cannot be discharged reliably and there are safety hazards. Compared with the prior art, the beneficial effects of the controller provided by the present application are the same as the beneficial effects of the discharge method provided by the above embodiment, and the other technical features in the discharge device are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0157] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0158] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0159] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer program) stored thereon, and the computer-readable program instructions are used to execute the discharge method in the above-mentioned embodiment.

[0160] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0161] The computer-readable storage medium may be included in the controller; or may exist independently without being assembled into the controller.

[0162] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0163] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0164] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0165] The readable storage medium provided in the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned discharge method, and can solve the technical problem that the DC bus high voltage cannot be discharged reliably and there are safety hazards. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in the present application are the same as the beneficial effects of the discharge method provided in the above-mentioned embodiment, and will not be repeated here.

[0166] The present application also provides a computer program product, including a computer program, which implements the steps of the above-mentioned discharge method when executed by a processor.

[0167] The computer program product provided by the present application can solve the technical problem that the DC bus high voltage cannot be discharged reliably, which poses a safety hazard. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the discharge method provided by the above embodiment, which will not be described in detail here.

[0168] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A discharge method, characterized in that: The method is applied to an electric drive system, the electric drive system at least comprising a controller, a motor winding and a target resistance, the method is executed by the controller, and the method comprises: receiving a discharge trigger signal; Determine whether the vehicle has collided according to the discharge trigger signal, and obtain a determination result; The DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the judgment result.

2. The discharge method according to claim 1, characterized in that: The step of determining whether the vehicle has collided according to the discharge trigger signal and obtaining a determination result comprises: Determine whether the vehicle has collided according to whether the discharge trigger signal is a hard-line state signal triggered by a collision event, and obtain a determination result; The step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the judgment result includes: When the vehicle does not collide, controlling the DC bus voltage to discharge through the motor winding and / or the target resistor according to the state of the main relay; When the vehicle collides, the DC bus voltage is controlled to be discharged through the target resistor.

3. The discharge method according to claim 2, characterized in that: The step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the state of the main relay when the vehicle does not collide includes: When the vehicle does not collide, determining whether to trigger an active discharge request; When the active discharge request is triggered and the active discharge request verification is passed, obtaining a state signal of a main relay in the electric drive system; When the state signal indicates that the main relay is in a disconnected state, determining a DC bus voltage to be discharged; The DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the state of the rotary transformer in the electric drive system.

4. The discharge method according to claim 3, characterized in that: The step of determining that there is a DC bus voltage that needs to be discharged when the state signal indicates that the main relay is in a disconnected state includes: When the state signal indicates that the main relay is in a disconnected state, collecting a first effective voltage signal and a second effective voltage signal at a preset position in the electric drive system; Determine whether there is a battery voltage signal fed back by the battery management system; If the battery voltage signal exists, determining the DC bus voltage to be discharged according to the battery voltage signal, the first effective voltage signal and the second effective voltage signal; If the battery voltage signal does not exist, the DC bus voltage to be discharged is determined according to the first effective voltage signal and the second effective voltage signal.

5. The discharge method according to claim 3, characterized in that: The step of controlling the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the state of the rotary transformer in the electric drive system comprises: Determining whether the rotary transformer in the electric drive system is in a fault state; If the fault state is not present, the DC bus voltage is controlled to be discharged through the motor winding and / or the target resistance according to the current vehicle speed; If it is in the fault state, the DC bus voltage is controlled to be discharged through the target resistor.

6. The discharge method according to any one of claims 3 to 5, characterized in that: After the step of obtaining the state signal of the main relay in the electric drive system when the active discharge request is triggered and the active discharge request is verified to be passed, the method further includes: When the state signal indicates that the main relay is in a closed state, determining a DC bus voltage to be discharged; The DC bus voltage is controlled to be discharged through the target resistance within a first preset time period.

7. The discharge method according to claim 1, characterized in that: After the step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the judgment result, the method further includes: During the process of the DC bus voltage being discharged through the motor winding, determining whether the DC bus voltage is lower than a preset reference voltage within a second preset time period; If the voltage is lower than the preset reference voltage within the second preset time period, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped; If the voltage is not lower than the preset reference voltage within the second preset time period, the remaining DC bus voltage is controlled to be discharged through the target resistor.

8. The discharge method according to claim 1, characterized in that: After the step of controlling the DC bus voltage to discharge through the motor winding and / or the target resistance according to the judgment result, the method further includes: During the process of the DC bus voltage being discharged through the target resistor, determining whether the DC bus voltage is lower than a preset reference voltage within a third preset time period; If the voltage is lower than the preset reference voltage within the third preset time period, it is determined that the DC bus voltage is discharged successfully, and the discharge of the DC bus voltage is stopped.

9. A discharge device, characterized in that: The discharge device comprises: A signal receiving module, used for receiving a discharge trigger signal; A collision judgment module, used for judging whether the vehicle has collided according to the discharge trigger signal, and obtaining a judgment result; The voltage discharge module is used to control the DC bus voltage to be discharged through the motor winding and / or the target resistance according to the judgment result.

10. A controller, characterized in that: The controller comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the discharge method according to any one of claims 1 to 8.

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