A high voltage up and down control method and control system for an electric vehicle controller

Abstract

The present invention relates to the technical field of vehicle controllers, and in particular to a high-voltage power-on and power-off control method and control system for an electric vehicle controller. The present invention improves the high-voltage power-on and power-off control method, adds a high-voltage circuit to confirm the disconnected state, and performs a logical AND operation on the timing result of the relay state detection timer and the relay state signal fed back by the BMS, thereby accurately judging whether the high-voltage circuit has been truly disconnected, thereby ensuring that the process of the VCU controlling the MCU to perform active discharge is not interrupted. The present invention solves the problem of timing disorder caused by a certain lag in the BMS executing the VCU's instructions when the user quickly and repeatedly rotates the key switch, overcomes the defect of unstable timing of traditional high-voltage power-on and power-off, effectively avoids the occurrence of vehicle breakdown, and improves user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle whole vehicle controllers, and in particular to a high-voltage power up and down control method and a control system for an electric vehicle whole vehicle controller. Background Art

[0002] Electric vehicles include hybrid vehicles and pure electric vehicles. The main feature that distinguishes them from traditional fuel vehicles is that electric vehicles have a high-voltage drive system, including power batteries, drive motors, high-voltage distribution boxes, etc. As the core control unit of electric vehicles, VCU (vehicle control unit) controls the high-voltage power on and off of the vehicle as one of its core functions. It collects signals from keys, brake pedals, gears, and charging guns, and communicates with controllers such as BMS (battery management system), MCU (motor controller) and DC / DC (direct current converter) through the CAN (controller area network) bus, thereby controlling the high-voltage power on and off of the vehicle safely. At the same time, during the power on and off process, it accurately diagnoses the high-voltage faults of the vehicle's power system and quickly handles them accordingly.

[0003] During the high-voltage power-on and power-off process of the vehicle controller in the prior art, when the user quickly powers on and off the power, the battery management system takes a certain amount of time to execute the instructions of the vehicle controller, which will cause timing confusion and vehicle misdiagnosis, resulting in vehicle failure and breakdown. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a high-voltage power on and off control method and control system for an electric vehicle whole controller are provided, which can improve the high-voltage power on and off control strategy of the electric vehicle whole controller, improve the stability of the power on and off timing, effectively avoid vehicle diagnostic failures, and enhance user experience.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A high voltage power-on and power-off control method for an electric vehicle controller includes the following control strategies:

[0007] After being awakened, the VCU enters the high-voltage circuit disconnected state by default. If the user turns the key to the ON position or the START position or the VCU receives the charging request signal from the BMS, it detects whether all the high-voltage controllers in the vehicle have issued a high-voltage connection permission signal. If so, the VCU enters the high-voltage circuit closed state, otherwise it continues to maintain the high-voltage circuit disconnected state;

[0008] If the user turns the key to the ACC position or the OFF position or the BMS stops sending the charging request signal, the VCU enters the high-voltage circuit ready to disconnect state;

[0009] If the BMS does not report that the relay is closed for more than t0 time in the high-voltage circuit closed state, or if the vehicle speed and power battery bus current meet the preset condition 1 in the high-voltage circuit ready to disconnect state, the VCU enters the high-voltage circuit confirmed disconnect state;

[0010] In the high-voltage circuit disconnection state, if the BMS does not feedback that the relay has been disconnected and exceeds the t1 time, the VCU enters the high-voltage circuit disconnection state again; if the BMS feedback relay has been disconnected and exceeds the t2 time, the VCU enters the active discharge state;

[0011] In the active discharge state, if it is detected that the motor bus voltage meets the preset condition 2, the VCU enters the high-voltage circuit disconnection state again.

[0012] Furthermore, when the high-voltage circuit is disconnected, the VCU continues to send a relay disconnection instruction to the BMS.

[0013] Furthermore, the in-vehicle high-voltage controller specifically includes: BMS, MCU, DC / DC and OBC.

[0014] Furthermore, when the high-voltage circuit is in a closed state, the VCU sends a relay closing instruction to the BMS and an enable instruction to the DC / DC, and simultaneously starts a relay closing state detection timer T0, and detects in real time whether the BMS feedback relay is closed.

[0015] Furthermore, when the high-voltage circuit is confirmed to be in a disconnected state, the VCU continues to send a relay closing instruction to the BMS and stops enabling the DC / DC, while limiting the output power of the AC and PTC to zero.

[0016] Furthermore, the preset condition one is specifically: the vehicle speed is less than 10km / h and the power battery bus current is less than 5A; the preset condition two is specifically: the motor bus voltage fed back by the MCU is less than or equal to 60V.

[0017] Furthermore, when the high-voltage circuit is confirmed to be in the disconnected state, the VCU sends a relay disconnection instruction to the BMS, and simultaneously starts the relay disconnection state detection timers T1 and T2, and detects in real time whether the BMS feedback relay is disconnected.

[0018] Based on the same inventive concept, the present invention also provides a high voltage power up and down control system for an electric vehicle controller, which is used to implement the control method described above.

[0019] Mainly include:

[0020] On-board charger OBC, used to connect to the vehicle slow charging port and charge the battery pack;

[0021] DC / DC converter, used to convert high-voltage DC power into low-voltage DC power for use with low-voltage electrical equipment in the vehicle;

[0022] Air conditioning controller AC, used to drive the air conditioning system in the car;

[0023] Motor controller MCU, used to drive the electric vehicle motor;

[0024] Electric heater PTC, used for heating the air conditioning and heating system in the car;

[0025] Battery management system BMS, used to control and feedback the working status of each relay in the battery pack;

[0026] The on-board charger, DC converter, air conditioning controller, motor controller, electric heater, and battery management system are all electrically connected to the vehicle controller VCU, and the vehicle controller is used to receive information and perform calculations and judgments to execute the control method described above.

[0027] Compared with the prior art, the present invention has the following main advantages:

[0028] 1. The present invention provides a high-voltage power-on and power-off control method for an electric vehicle controller. By improving the high-voltage power-on and power-off control method, a new high-voltage circuit is added to confirm the disconnection state. By performing a logic AND operation on the timing result of the relay state detection timer and the relay state signal fed back by the BMS, it is accurately determined whether the high-voltage circuit has been truly disconnected, thereby ensuring that the process of the VCU controlling the MCU to perform active discharge is not interrupted;

[0029] 2. The control system provided by the present invention solves the problem of timing disorder caused by a certain lag in the BMS executing the VCU's instructions when the user quickly and repeatedly rotates the key switch, overcomes the defect of unstable timing of traditional high-voltage power on and off, effectively avoids the occurrence of vehicle breakdown, and improves user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a high voltage power-on and power-off control method of an electric vehicle controller in an embodiment of the present invention;

[0031] Figure 2 The figure is a schematic diagram of a high voltage power up and down control system of an electric vehicle controller in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention 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 invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0034] Embodiment 1: This embodiment provides a method for controlling the high voltage power on and off of an electric vehicle controller, which is used to solve the problem of timing disorder and vehicle failure caused by a certain lag in the BMS executing the VCU instruction when the user quickly and repeatedly rotates the key switch in the prior art. It mainly includes the following solutions:

[0035] After being awakened, the VCU enters the high-voltage circuit disconnected state by default. If the user turns the key to the ON position or the START position or the VCU receives the charging request signal from the BMS, it detects whether all the high-voltage controllers in the vehicle have issued a high-voltage connection permission signal. If so, the VCU enters the high-voltage circuit closed state, otherwise it continues to maintain the high-voltage circuit disconnected state;

[0036] If the user turns the key to the ACC position or the OFF position or the BMS stops sending the charging request signal, the VCU enters the high-voltage circuit ready to disconnect state;

[0037] If the BMS does not report that the relay is closed for more than t0 time in the high-voltage circuit closed state, or if the vehicle speed and power battery bus current meet the preset condition 1 in the high-voltage circuit ready to disconnect state, the VCU enters the high-voltage circuit confirmed disconnect state;

[0038] In the high-voltage circuit disconnection state, if the BMS does not feedback that the relay has been disconnected and exceeds the t1 time, the VCU enters the high-voltage circuit disconnection state again; if the BMS feedback relay has been disconnected and exceeds the t2 time, the VCU enters the active discharge state;

[0039] In the active discharge state, if it is detected that the motor bus voltage meets the preset condition 2, the VCU enters the high-voltage circuit disconnection state again.

[0040] This method overcomes the defect of unstable timing of traditional high-voltage power on and off by improving the control strategy, effectively avoids the occurrence of vehicle breakdown, and improves user experience.

[0041] Embodiment 2: The principle and technical solution of this embodiment are basically the same as those of embodiment 1. This embodiment provides a high voltage up and down power control method for an electric vehicle controller, such as Figure 1 As shown, the specific steps are as follows:

[0042] Step 1: After being awakened, the VCU (vehicle control unit) enters the high-voltage circuit disconnection state by default. In this state, the VCU sends a relay disconnection command to the BMS (battery management system). If the user turns the key to the ON position or the START position or the VCU receives a charging request signal from the BMS, step 2 is executed, otherwise the high-voltage circuit disconnection state is maintained;

[0043] Step 2: VCU detects whether various high-voltage controllers such as BMS, MCU (motor controller), DC / DC (direct current converter) and OBC (on-board charger) have issued a high-voltage connection permission signal. If the conditions are met, the high-voltage circuit is closed. VCU sends a relay closing command to BMS and starts timing T0. If BMS does not feedback that the relay is closed within 5s, step 4 is executed. If VCU receives a relay closing signal from BMS within 5s, the high-voltage circuit continues to be closed and an enable command is sent to DC / DC.

[0044] Step 3: If the user turns the key to the ACC position (full vehicle power-on position) or the OFF position or the BMS stops sending the charging request signal, the VCU enters the high-voltage circuit ready to disconnect state. In this state, the VCU sends a relay closing command to the BMS, stops enabling DC / DC, limits the power output of AC (air conditioning controller) and PTC (electric heater) to zero, and detects whether the vehicle speed is less than 10km / h and whether the power battery bus current is less than 5A. If the conditions are met, execute step 4, otherwise continue to maintain the high-voltage circuit ready to disconnect state;

[0045] Step 4: VCU enters the high-voltage circuit to confirm the disconnection state and starts the relay disconnection state detection timers T1 and T2 at the same time, and sends a relay disconnection instruction to the BMS. If the BMS does not feedback that the relay is disconnected and the relay state detection timer T1 times 2s, then execute step 6. If the BMS feedbacks that the relay is disconnected and the relay state detection timer T2 times 1.5s, then execute step 5. Otherwise, continue to maintain the high-voltage circuit confirmation disconnection state;

[0046] Step 5. VCU enters the active discharge state. VCU sends a relay disconnection command to BMS and an active discharge command to MCU. If the active discharge timer T3 times 5s or the motor bus voltage fed back by MCU is less than or equal to 60V, execute step 6, otherwise continue to maintain the active discharge state.

[0047] Step 6: VCU enters the high-voltage circuit disconnection state again and sends a relay disconnection command to the BMS.

[0048] Embodiment 3, based on the same inventive concept, this embodiment also provides a high voltage up and down power control system for an electric vehicle controller, which is used to implement the control method as described above, such as Figure 2 As shown, it mainly includes:

[0049] On-board charger OBC, used to connect to the vehicle slow charging port and charge the battery pack;

[0050] DC / DC converter, used to convert high-voltage DC power into low-voltage DC power for use with low-voltage electrical equipment in the vehicle;

[0051] Air conditioning controller AC, used to drive the air conditioning system in the car;

[0052] Motor controller MCU, used to drive the electric vehicle motor;

[0053] Electric heater PTC, used for heating the air conditioning and heating system in the car;

[0054] Battery management system BMS, used to control and feedback the working status of each relay in the battery pack;

[0055] The on-board charger, DC converter, air conditioning controller, motor controller, electric heater, and battery management system are all electrically connected to the vehicle controller VCU, and the vehicle controller is used to receive information and perform calculations and judgments to execute the control method described above.

[0056] In the figure, C1 and C2 are both power battery modules; S1 is the positive relay; S2 is the negative relay; S3 is the pre-charge relay; S4 is the fast charge positive relay, and S5 is the fast charge negative relay; R1 is the pre-charge resistor; F1, F2, F3, F4, and F5 are all fuses.

[0057] Embodiment 4: Based on the same inventive concept, this embodiment also provides a manual-automatic vehicle, which is equipped with the electric vehicle controller high-voltage power up and down control system as described above.

[0058] In summary:

[0059] 1. The present invention provides a high-voltage power-on and power-off control method for an electric vehicle controller. By improving the high-voltage power-on and power-off control method, a new high-voltage circuit is added to confirm the disconnection state. By performing a logic AND operation on the timing result of the relay state detection timer and the relay state signal fed back by the BMS, it is accurately determined whether the high-voltage circuit has been truly disconnected, thereby ensuring that the process of the VCU controlling the MCU to perform active discharge is not interrupted;

[0060] 2. The control system provided by the present invention solves the problem of timing disorder caused by a certain lag in the BMS executing the VCU's instructions when the user quickly and repeatedly rotates the key switch, overcomes the defect of unstable timing of traditional high-voltage power on and off, effectively avoids the occurrence of vehicle breakdown, and improves user experience.

[0061] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high voltage power up and down control method for an electric vehicle controller, characterized in that: The control strategies include: After the vehicle controller is awakened, it enters the high-voltage circuit disconnected state by default. If the user turns the key to the ON position or the START position or the vehicle controller receives a charging request signal from the battery management system, it detects whether all high-voltage controllers in the vehicle send a high-voltage connection permission signal. If so, the vehicle controller enters the high-voltage circuit closed state, otherwise it continues to maintain the high-voltage circuit disconnected state; If the user turns the key to the ACC or OFF position or the battery management system stops sending the charging request signal, the vehicle controller enters the high-voltage circuit ready to disconnect state; If the battery management system does not feedback that the relay is closed for more than t0 time in the high-voltage circuit closed state, or detects that the vehicle speed and power battery bus current meet the preset condition 1 in the high-voltage circuit ready to disconnect state, the vehicle controller enters the high-voltage circuit confirmation disconnection state; In the high-voltage circuit disconnection state, if the battery management system does not feedback that the relay has been disconnected and exceeds the t1 time, the vehicle controller enters the high-voltage circuit disconnection state again. If the battery management system feedbacks that the relay has been disconnected and exceeds the t2 time, the vehicle controller enters the active discharge state; In the active discharge state, if it is detected that the motor bus voltage meets the preset condition 2, the vehicle controller enters the high-voltage circuit disconnection state again; The in-vehicle high-voltage controller specifically includes: a battery management system, a motor controller, a DC converter and an on-board charger; The preset condition 1 is specifically: the vehicle speed is less than 10 km / h and the power battery bus current is less than 5A; The second preset condition is specifically: the motor bus voltage fed back by the motor controller is less than or equal to 60V; The relays specifically include a positive relay S1, a negative relay S2, a pre-charge relay S3, a fast charge positive relay S4 and a fast charge negative relay S5 in the battery pack.

2. A high voltage power up and down control method for an electric vehicle controller according to claim 1, characterized in that: When the high-voltage circuit is disconnected, the vehicle controller continues to send a relay disconnection instruction to the battery management system.

3. The high voltage power up and down control method of an electric vehicle controller according to claim 1 is characterized in that: When the high-voltage circuit is in the closed state, the vehicle controller sends a relay closing instruction to the battery management system and an enable instruction to the DC converter, and at the same time starts the relay closing state detection timer T0, and detects in real time whether the battery management system feedback relay is closed.

4. A high voltage power up and down control method for an electric vehicle controller according to claim 3, characterized in that: When the high-voltage circuit is confirmed to be disconnected, the vehicle controller continues to send a relay closing instruction to the battery management system and stops enabling the DC converter, while limiting the output power of the air-conditioning controller and the electric heater to zero.

5. The high voltage power up and down control method of an electric vehicle controller according to claim 1 is characterized in that: When the high-voltage circuit is confirmed to be in the disconnected state, the vehicle controller sends a relay disconnection instruction to the battery management system, and simultaneously starts the relay disconnection state detection timers T1 and T2, and detects in real time whether the battery management system feedback relay has been disconnected.

6. A high voltage power up and down control system for an electric vehicle controller, used to implement the control method as claimed in any one of claims 1 to 5, characterized in that: include: On-board charger, used to connect to the vehicle slow charging port and charge the battery pack; DC converter, used to convert high-voltage DC power into low-voltage DC power for use with low-voltage electrical equipment in the vehicle; Air conditioning controller, used to drive the air conditioning system in the car; Motor controller, used to drive the electric vehicle motor; Electric heater, used for heating the air conditioning and heating system in the car; Battery management system, used to control and provide feedback on the working status of each relay in the battery pack; The on-board charger, DC converter, air-conditioning controller, motor controller, electric heater, and battery management system are all electrically connected to the vehicle controller, and the vehicle controller is used to receive information and perform calculations and judgments to execute the control method described in any one of claims 1 to 5.

7. A non-transitory readable storage medium having a program stored thereon, characterized in that: When the program is executed by the high-voltage power-on and power-off control system of the electric vehicle controller, the control method as described in any one of claims 1 to 5 is implemented.

8. An electric vehicle, characterized in that: It includes the high voltage up and down power control system of the electric vehicle whole vehicle controller as described in claim 6.

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