Method for controlling external load discharge of electric automobile

Abstract

The invention discloses a control method for discharging an external load of an electric vehicle, which comprises the following steps of: in response to a gun insertion discharging signal, waking up a vehicle-mounted charger, and waking up a battery management system and a vehicle control unit at the same time; the battery management system sends a charger inversion enable signal to the vehicle-mounted charger; after the vehicle-mounted charger receives the charger inversion enable signal, an inversion loop is controlled to be closed, and inversion is controlled to output required current; when the condition of quitting the inverter discharge is met, the battery management system sends an inverter disable signal to the vehicle-mounted charger, so that the vehicle-mounted charger controls the inverter to stop outputting; and the battery management system quits inversion and enters a sleep mode. According to the control method for external load discharge of the electric automobile, control over external load discharge can be intelligently achieved through interaction of the vehicle-mounted charger and the battery management system, universality is achieved, and meanwhile on the premise that the safety of the automobile is not affected, the convenience of automobile production and inspection is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and more specifically, to a control method for external load discharging of an electric vehicle. Background Art

[0002] With the rapid development of the electric vehicle industry at home and abroad in recent years and the entry into the intelligent era, the automobile is not only a means of transportation, but also a considerate travel partner for the car owner. For example, with the V2L (Vehicle to Load) external discharging function, the battery pack with built-in direct current can be converted into 220V alternating current through an inverter and output externally. The V2L function makes the vehicle more in line with life scenarios and has many more applications.

[0003] Due to the unreasonable or ill-adapted management of the current control method for external load discharging, related faults of the on-vehicle charger OBC, the automatic sleep mode, and the signal interaction with the battery management system BMS result in inverter power limitation or inverter discharging stop, all of which will affect the realization of the V2L function.

[0004] Therefore, there is an urgent need for a control method for external load discharging of an electric vehicle. Summary of the Invention

[0005] The purpose of the present invention is to provide a control method for external load discharging of an electric vehicle to solve the above problems in the prior art, which can intelligently control external load discharging, has universality, and at the same time improves the convenience of vehicle production and inspection without affecting vehicle safety.

[0006] The present invention provides a control method for external load discharging of an electric vehicle, which includes:

[0007] In response to the plug-in discharging signal, wake up the on-vehicle charger, and at the same time wake up the battery management system and the vehicle controller;

[0008] The battery management system sends a charger inverter enable signal to the on-vehicle charger;

[0009] After receiving the charger inverter enable signal, the on-vehicle charger controls the closing of the inverter circuit and controls the inverter output demand current;

[0010] When the condition for exiting inverter discharging is met, the battery management system sends an inverter disable signal to the on-vehicle charger so that the on-vehicle charger controls the inverter to stop outputting;

[0011] The battery management system exits the inverter and enters the sleep mode.

[0012] The control method for external load discharging of the electric vehicle as described above, wherein, preferably, in response to the plug-in gun discharging signal, the on-vehicle charger is woken up, and at the same time, the battery management system and the vehicle controller are woken up, which specifically includes:

[0013] When plugging in the gun for discharging, the on-vehicle charger with CC wake-up function is woken up;

[0014] After the on-vehicle charger is woken up, the battery management system and the vehicle controller connected to the on-vehicle charger through hard wires receive the OBC wake-up signal and are woken up. The battery management system powers on at low voltage and performs self-check.

[0015] The control method for external load discharging of the electric vehicle as described above, wherein, preferably, the battery management system sends a charger inversion enable signal to the on-vehicle charger, which specifically includes:

[0016] The on-vehicle charger feeds back AC charging information to the battery management system through a message;

[0017] After the battery management system receives that the CC resistance value sent by the on-vehicle charger is for inversion connection, the battery management system sends a charging request to the vehicle controller and enters the high-voltage charging process;

[0018] The vehicle controller sends permission-to-charge information to the battery management system;

[0019] The battery management system sends the charger inversion enable signal for starting to discharge to the on-vehicle charger.

[0020] The control method for external load discharging of the electric vehicle as described above, wherein, preferably, after the on-vehicle charger receives the charger inversion enable signal, it controls the inversion circuit to close and controls the inversion output demand current, which specifically includes:

[0021] After the on-vehicle charger receives the charger inversion enable signal, it controls the inversion circuit to close;

[0022] The battery management system sends the permitted discharge current and the current voltage to the on-vehicle charger;

[0023] The on-vehicle charger controls the inversion output demand current according to the permitted discharge current and the current voltage sent by the battery management system.

[0024] The control method for external load discharging of the electric vehicle as described above, wherein, preferably, when the conditions for exiting the inversion discharge are met, the battery management system sends an inversion disable signal to the on-vehicle charger so that the on-vehicle charger controls the inversion to stop output, which specifically includes:

[0025] When the conditions for exiting the inversion discharge are met, the battery management system sends an inversion disable signal for normal stop or fault stop to the on-vehicle charger;

[0026] After receiving the inverter disable signal for normal stop or fault stop, the on-vehicle charger controls the inverter to stop output.

[0027] When the sleep conditions are met, the on-vehicle charger enters the sleep mode.

[0028] For the control method of external load discharge of the electric vehicle as described above, preferably, the battery management system exits the inverter and enters the sleep mode, specifically including:

[0029] The battery management system sends an inverter disable and no-request charging request to the vehicle controller.

[0030] After receiving the inverter disable and no-request charging request, the vehicle controller sends a power-down command to the battery management system to complete the high-voltage power-down of the whole vehicle.

[0031] The battery management system enters the sleep mode.

[0032] For the control method of external load discharge of the electric vehicle as described above, preferably, the control method of external load discharge of the electric vehicle further includes:

[0033] During the process of controlling the inverter to output the required current, it is judged whether the inverter discharge stop condition is met. If it is met, the inverter discharge is stopped.

[0034] Among them, the inverter discharge stop condition includes at least one of the following: the battery management system stops discharging due to a fault, the on-vehicle charger feedbacks a CC fault to the battery management system, or an electronic lock fault or an OBC fault level is 3, the CC resistance value changes, and the discharge gun S2 switch button is pressed.

[0035] For the control method of external load discharge of the electric vehicle as described above, preferably, the control method of external load discharge of the electric vehicle further includes:

[0036] During the process of controlling the inverter to output the required current, it is judged whether the OBC fault level is 2. If it is, the inverter enters the power limit mode.

[0037] For the control method of external load discharge of the electric vehicle as described above, preferably, the control method of external load discharge of the electric vehicle further includes:

[0038] During the process of controlling the inverter to output the required current, the battery management system does not need to perform the heating function, and the electronic lock is not allowed to be locked.

[0039] For the control method of external load discharge of the electric vehicle as described above, preferably, the control method of external load discharge of the electric vehicle further includes:

[0040] After the on-vehicle charger is awakened, if the SOC is lower than the preset threshold, the inverter discharge function is not allowed to be turned on. After waiting for the preset time, the on-vehicle charger automatically enters the sleep mode.

[0041] The present invention provides a control method for external load discharge of an electric vehicle. Through the interaction between the on-vehicle charger and the battery management system, it can intelligently realize the control of external load discharge, has universality, and at the same time, without affecting the vehicle safety, improves the convenience of vehicle production and inspection; it can effectively realize the control of the vehicle's external load discharge, provides a solution for optimizing the control method of electric vehicles, can not only effectively improve the product quality at the time of factory, timely discover potential safety hazards, but also improve user satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described below in conjunction with the drawings, where:

[0043] Figure 1 is a flowchart of an embodiment of the control method for external load discharge of an electric vehicle provided by the present invention;

[0044] Figure 2 is a logic diagram of an embodiment of the control method for external load discharge of an electric vehicle provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] Now, various exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. The description of the exemplary embodiments is merely illustrative and in no way limits the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, the components of materials, numerical expressions and values set forth in these embodiments should be construed as merely exemplary and not as limitations.

[0046] The "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different parts. The terms such as "comprising" or "including" mean that the elements before this term cover the elements listed after this term, and do not exclude the possibility of also covering other elements. The terms such as "upper" and "lower" are only used to represent the relative positional relationship, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0047] In the present disclosure, when it is described that a specific component is located between a first component and a second component, there may or may not be an intermediate component between the specific component and the first component or the second component. When it is described that a specific component is connected to other components, the specific component may be directly connected to the other components without an intermediate component, or may not be directly connected to the other components but have an intermediate component.

[0048] All terms used in the present disclosure (including technical terms or scientific terms) have the same meaning as understood by those of ordinary skill in the art to which the present disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, for example, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such herein.

[0049] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0050] Currently, the control method for external load discharging of electric vehicles generally involves connecting the AC charging socket, OBC, and battery pack through high- and low-voltage wiring harnesses. There are problems such as related failures of the on-board charger OBC, signal interaction between the automatic sleep mode and the battery management system BMS, which result in inverter power limitation or inverter discharge stop, causing the vehicle to be unable to achieve the V2L function and affecting the user's driving experience.

[0051] As Figure 1 and Figure 2 shown, in the actual execution process of the control method for external load discharging of the electric vehicle provided in this embodiment, it specifically includes the following steps:

[0052] Step S1: In response to the gun insertion discharge signal, wake up the on-board charger (OBC), and at the same time wake up the battery management system (BMS) and the vehicle controller (VCU).

[0053] In an implementation manner of the control method for external load discharging of the electric vehicle of the present invention, step S1 may specifically include:

[0054] Step S11: When the gun is inserted for discharging, the on-board charger with the CC wake-up function is woken up.

[0055] After the on-board charger is woken up, the battery management system and the vehicle controller connected to the on-board charger through hard wires receive the OBC wake-up signal and are woken up. The battery management system powers on at low voltage and performs self-check.

[0056] When the vehicle-mounted charger with CC wake-up function is plugged in and discharging, it will wake up, and at the same time wake up the battery management system and the vehicle controller. The battery management system powers on at low voltage and performs self-check.

[0057] Step S2: The battery management system sends a charger inverter enable signal to the vehicle-mounted charger.

[0058] In an implementation manner of the control method for external load discharging of the electric vehicle of the present invention, the step S2 may specifically include:

[0059] Step S21: The vehicle-mounted charger feeds back AC charging information to the battery management system through a message.

[0060] Step S22: After the battery management system receives that the CC resistance value sent by the vehicle-mounted charger is for inverter connection, the battery management system sends a charging request to the vehicle controller and enters the high-voltage charging process;

[0061] Step S23: The vehicle controller sends permission to charge information to the battery management system.

[0062] Step S24: The battery management system sends the charger inverter enable signal for starting discharge to the vehicle-mounted charger.

[0063] The vehicle-mounted charger feeds back AC charging information to the battery management system, the battery management system sends a charging request to the vehicle controller, the vehicle controller sends permission to charge information to the battery management system, and the battery management system sends a charger inverter enable signal to the vehicle-mounted charger.

[0064] Step S3: After receiving the charger inverter enable signal, the vehicle-mounted charger controls the inverter circuit to close and controls the inverter output demand current.

[0065] In an implementation manner of the control method for external load discharging of the electric vehicle of the present invention, the step S3 may specifically include:

[0066] Step S31: After receiving the charger inverter enable signal, the vehicle-mounted charger controls the inverter circuit to close.

[0067] Step S32: The battery management system sends the allowed discharge current and the current voltage to the vehicle-mounted charger.

[0068] Step S33: The vehicle-mounted charger controls the inverter output demand current according to the allowed discharge current and the current voltage sent by the battery management system.

[0069] After the OBC receives the charger inverter enable signal, the inverter circuit is controlled to close, and according to the allowed discharge current and the current voltage sent by the BMS, the OBC controls the inverter output demand current.

[0070] Step S4: When the condition for exiting the inverter discharge is satisfied, the battery management system sends an inverter disable signal to the on-vehicle charger to enable the on-vehicle charger to control the inverter to stop outputting.

[0071] In an embodiment of the control method for external load discharge of the electric vehicle of the present invention, the step S4 may specifically include:

[0072] Step S41: When the condition for exiting the inverter discharge is satisfied, the battery management system sends an inverter disable signal of "normal stop / fault stop" to the on-vehicle charger.

[0073] Step S42: After receiving the inverter disable signal of "normal stop / fault stop", the on-vehicle charger controls the inverter to stop outputting.

[0074] Step S43: When the sleep condition is satisfied, the on-vehicle charger enters the sleep mode.

[0075] When the condition for exiting the inverter discharge is satisfied, the BMS sends an inverter disable signal "normal stop / fault stop", the OBC controls the inverter to stop outputting, and the OBC enters the sleep mode.

[0076] Step S5: The battery management system exits the inverter and enters the sleep mode.

[0077] In an embodiment of the control method for external load discharge of the electric vehicle of the present invention, the step S5 may specifically include:

[0078] Step S51: The battery management system sends an inverter disable and no-request charging request to the vehicle control unit.

[0079] Step S52: After receiving the inverter disable and no-request charging request, the vehicle control unit sends a power-down command to the battery management system to complete the high-voltage power-down of the whole vehicle.

[0080] Step S53: The battery management system enters the sleep mode.

[0081] Exit the inverter, the BMS sends an inverter disable and no-request charging request to the VCU and waits for the power-down command to complete the high-voltage power-down of the whole vehicle, and the BMS sleeps.

[0082] Further, in some embodiments of the present invention, the control method for external load discharge of the electric vehicle further includes:

[0083] Step S6: During the process of controlling the inverter to output the required current, it is judged whether the condition for stopping the inverter discharge is satisfied. If so, the inverter discharge is stopped.

[0084] Among them, the conditions for stopping the inverter discharge include at least one of the following: the battery management system stops the discharge fault, the on-board charger feeds back a CC fault or an electronic lock fault or the OBC fault level is 3 to the battery management system, the CC resistance value changes, and the discharge gun S2 switch button is pressed. Specifically, the change in the CC resistance value means that the CC resistance value is not within the range of the inverter connection resistance value.

[0085] Furthermore, in some embodiments of the present invention, the method for controlling the external load discharge of the electric vehicle further includes:

[0086] Step S7: During the process of controlling the inverter output demand current, determine whether the OBC fault level is 2. If so, enter the inverter power limit mode.

[0087] Further, in some embodiments of the present invention, the method for controlling the external load discharge of the electric vehicle further includes:

[0088] Step S8: During the process of controlling the inverter output demand current, the battery management system does not need to perform the heating function, and the electronic lock is not allowed to be locked.

[0089] Further, in some embodiments of the present invention, the method for controlling the external load discharge of the electric vehicle further includes:

[0090] Step S8: After the on-board charger is awakened, if the SOC is lower than a preset threshold (for example, 20%), the inverter discharge function is not allowed to be turned on. After waiting for a preset time (for example, 3 minutes), the on-board charger automatically enters the sleep mode.

[0091] It should be noted that the present invention does not make specific limitations on the preset threshold and the preset time. The manufacturer can define the waiting preset time by itself, or the manufacturer can define the sleep mode by itself. The present invention does not make specific limitations on this.

[0092] The method for controlling the external load discharge of the electric vehicle provided by the embodiments of the present invention can intelligently realize the control of the external load discharge through the interaction between the on-board charger and the battery management system, has universality, and at the same time, without affecting the vehicle safety, improves the convenience of vehicle production and inspection; can effectively realize the control of the vehicle's external load discharge, provides a solution for optimizing the control method of electric vehicles, not only can effectively improve the product quality at the factory, timely discover potential safety hazards, but also can improve user satisfaction.

[0093] So far, the embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details well known in the art have not been described. Those skilled in the art can clearly understand how to implement the technical solutions disclosed herein based on the above description.

[0094] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or partial technical features can be equivalently replaced without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A control method for external load discharge of an electric vehicle, characterized in that, Including: In response to the signal of plugging in the gun for discharging, wake up the on-vehicle charger, and at the same time wake up the battery management system and the vehicle controller; The battery management system sends a charger inverter enabling signal to the on-vehicle charger; After receiving the charger inverter enabling signal, the on-vehicle charger controls the closing of the inverter circuit and controls the inverter to output the required current; When the condition for exiting the inverter discharge is met, the battery management system sends a non-enabling signal for the inverter to the on-vehicle charger, so that the on-vehicle charger controls the inverter to stop outputting; The battery management system exits the inverter and enters the sleep mode.

2. The control method for external load discharging of the electric vehicle according to claim 1, characterized in that, The step of, in response to the signal of plugging in the gun for discharging, waking up the on-vehicle charger, and at the same time waking up the battery management system and the vehicle controller specifically includes: When plugging in the gun for discharging, the on-vehicle charger with the CC wake-up function is woken up; After the on-vehicle charger is woken up, the battery management system and the vehicle controller connected to the on-vehicle charger through hard wires receive the OBC wake-up signal and are woken up, and the battery management system powers on at low voltage and performs self-check.

3. The control method for external load discharge of the electric vehicle according to claim 1, characterized in that, The step of the battery management system sending a charger inverter enabling signal to the on-vehicle charger specifically includes: The on-vehicle charger feeds back AC charging information to the battery management system through a message; After the battery management system receives that the CC resistance value sent by the on-vehicle charger is for inverter connection, the battery management system sends a charging request to the vehicle controller and enters the process of charging and boosting the high voltage; The vehicle controller sends permission for charging information to the battery management system; The battery management system sends the charger inverter enabling signal for starting to discharge to the on-vehicle charger.

4. The control method for external load discharging of the electric vehicle according to claim 1, characterized in that, The step of, after the on-vehicle charger receives the charger inverter enabling signal, controlling the closing of the inverter circuit and controlling the inverter to output the required current specifically includes: After the on-vehicle charger receives the charger inverter enabling signal, control the closing of the inverter circuit; The battery management system sends the permitted discharge current and the current voltage to the on-vehicle charger; The on-vehicle charger controls the inverter to output the required current according to the permitted discharge current and the current voltage sent by the battery management system.

5. The control method for external load discharging of the electric vehicle according to claim 1, wherein The step of, when the condition for exiting the inverter discharge is met, the battery management system sending a non-enabling signal for the inverter to the on-vehicle charger, so that the on-vehicle charger controls the inverter to stop outputting specifically includes: When the condition for exiting the inverter discharge is met, the battery management system sends a non-enabling signal for normal stop or fault stop of the inverter to the on-vehicle charger; After receiving the non-enabling signal for normal stop or fault stop of the inverter, the on-vehicle charger controls the inverter to stop outputting; When the sleep condition is met, the on-vehicle charger enters the sleep mode.

6. The control method for external load discharge of the electric vehicle according to claim 1, wherein The step of the battery management system exiting the inverter and entering the sleep mode specifically includes: The battery management system sends a non-enabling signal for the inverter and a non-request charging request to the vehicle controller; After receiving the non-enabling signal for the inverter and the non-request charging request, the vehicle controller sends a power-down command to the battery management system to complete the high-voltage power-down of the vehicle; The battery management system enters the sleep mode.

7. The control method for external load discharge of the electric vehicle according to claim 1, wherein The control method for the external load discharge of the electric vehicle further includes: During the process of controlling the inverter to output the required current, judge whether the condition for stopping the inverter discharge is met. If it is met, stop the inverter discharge. Among them, the conditions for stopping the inverter discharge include at least one of the following: the battery management system stops the discharge fault, the on-board charger feeds back a CC fault or an electronic lock fault or the OBC fault level is 3 to the battery management system, the CC resistance value changes, and the discharge gun S2 switch button is pressed.

8. The control method for external load discharging of the electric vehicle according to claim 1, characterized in that, The control method for the external load discharge of the electric vehicle further includes: During the process of controlling the required current of the inverter output, it is judged whether the OBC fault level is 2. If so, the inverter limited power mode is entered.

9. The control method for external load discharge of the electric vehicle according to claim 1, wherein The control method for the external load discharge of the electric vehicle further includes: During the process of controlling the required current of the inverter output, the battery management system does not need to perform the heating function, and the electronic lock is not allowed to be locked.

10. The control method for external load discharge of the electric vehicle according to claim 1, wherein The control method for the external load discharge of the electric vehicle further includes: After the on-board charger is awakened, if the SOC is lower than the preset threshold, the inverter discharge function is not allowed to be turned on. After waiting for the preset time, the on-board charger automatically enters the sleep mode.

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