Control method for series-parallel connection change-over switch of battery pack module for new energy vehicle

Abstract

A control method of a new energy vehicle battery pack module series-parallel connection change-over switch comprises the following steps that S1, when a charging port of a vehicle is inserted into a charging gun of a charging pile, a charging control unit is awakened; s2, the charging control unit detects the highest charging voltage corresponding to the charging pile, and compares the highest charging voltage with the working voltage of the battery pack module of the vehicle; S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit controls the change-over switch to keep an initial state; s22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit controls a change-over switch to execute a switching action; and S3, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is finished. According to the scheme, the new energy vehicle can automatically adapt to two different charging voltages, and the universality is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle charging technology, and in particular to a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle. Background Art

[0002] In recent years, the electrification of automobiles has become an irreversible trend, and the new energy vehicle industry has entered the fast lane of development. The development of the new energy vehicle industry has been greatly promoted by technological progress. The progress of power battery technology has made up for the endurance gap. At the current technical level of new energy vehicles, the voltage level of the battery pack is generally in the range of 400V, but the traditional new energy vehicles have a long charging time, which has gradually become one of the obstacles to the rapid popularization of new energy vehicles. Users' demand for charging speed is growing, so 800V high-voltage fast charging technology came into being, aiming to achieve fast charging, shorten charging and energy replenishment time, and improve user experience.

[0003] An effective way to shorten the charging time and increase the charging rate is to increase the charging power. One way to increase the charging power is to increase the charging current on the existing 400V voltage battery pack platform. However, the power loss of the charging line, that is, the heat power, is proportional to the square of the charging current. The increase in charging current will cause a significant increase in the power loss from the charging device through the charging cable to the battery pack, that is, the heat power of the entire line will increase significantly. This method increases the charging current while reducing the heat power. It is necessary to reduce the resistance value of the entire charging circuit. The charging equipment needs to be replaced with higher specification connectors and use thicker diameter charging cables. This not only increases the construction cost, but also makes the overly thick and heavy charging cables very inconvenient to use.

[0004] Another way to increase the charging power is to increase the charging voltage, such as using 800V fast charging, which can double the charging power without increasing the charging current. Because this method does not increase the charging current, it will not increase the charging power loss while increasing the charging power, and the charging equipment does not need to be replaced with a larger diameter charging cable.

[0005] Compared with the 400V low voltage, the 800V battery pack system for new energy vehicles also has many advantages. For example, the charging rate can be doubled while maintaining the same charging current, and the charging current can be reduced while maintaining the same charging power. This design can reduce the size of the conductive parts inside the vehicle while reducing the amount of conductive metal materials. It can improve the charging efficiency of the whole vehicle while reducing the manufacturing cost of the whole vehicle and achieving lightweight.

[0006] However, in the new energy vehicle market, 400V battery pack platforms and 800V battery pack platforms coexist, and there will be a mismatch between the vehicle battery system voltage and the charging equipment voltage. For example, a vehicle with an 800V battery pack platform cannot directly use a 400V charging device, and a vehicle with a 400V battery pack platform cannot directly use an 800V charging device. This situation will restrict the high-voltage process of new energy vehicles and reduce user experience. Obviously, the mismatch between the working voltage of the battery pack module of the new energy vehicle and the voltage value of the charging equipment has led to the inability to charge, which has become a problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to solve the problem in the prior art that the working voltage of the battery pack module of the new energy vehicle does not match the voltage value of the charging device, resulting in the inability to charge.

[0008] To solve the above problems, the present invention provides a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle, which is applied to a new energy vehicle, wherein the new energy vehicle has a charging port, a charging control unit, a charging circuit and a battery pack module, wherein the charging circuit is used to connect the charging port and the battery pack module, wherein the battery pack module includes a first battery pack and a second battery pack, wherein the charging circuit is provided with a conversion switch for controlling the first battery pack and the second battery pack to be connected in series or in parallel with each other, and the charging control unit is electrically connected to the conversion switch; The steps include: S1. When the charging port of the vehicle is plugged into the charging gun of the charging pile, the charging control unit is awakened, and the conversion switch is powered and in the initial position; S2. The charging control unit detects the maximum charging voltage corresponding to the charging pile and compares it with the working voltage of the vehicle's battery pack module: S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to maintain the initial position, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and then enters S31; S22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to perform a switching action, that is, to change the series-parallel state of the first battery pack and the second battery pack of the battery pack module, and then the charging control unit detects the highest charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, S32 is executed; if they are different, S23 is executed; S23, the charging control unit controls the conversion switch to reset to the initial state, and at the same time, the charging control unit issues an alarm message indicating charging incompatibility; S31, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; S32, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed, and then the charging control unit controls the conversion switch to reset to the initial state.

[0009] The above scheme detects the maximum charging voltage of the charging pile through the charging control unit, so that when the maximum charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, it means that the charging pile and the battery pack module are currently compatible, so the charging control unit controls the conversion switch to maintain the initial position, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; and when the maximum charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, it means that the charging pile and the battery pack module are currently incompatible, and the charging control unit controls the conversion switch to perform a switching action, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is changed, and then the charging control unit detects the maximum charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; if they are different, the electrical control unit controls the conversion switch to reset to the initial state, and the charging control unit issues an alarm message of charging incompatibility. Compared with the existing technology, the above solution enables new energy vehicles to automatically adapt to two different charging voltages, effectively improving versatility.

[0010] In an improved solution, the conversion switch has an electric actuator, which controls the first battery group and the second battery group to be connected in series or in parallel with each other through mechanical movement. The electric actuator controls the first battery group and the second battery group to be connected in series or in parallel with each other through mechanical movement, and has good reliability.

[0011] In an improved solution, the charging control unit and the switching switch communicate via a level signal: when the charging control unit sends a low level signal to the switching switch, the switching switch maintains an initial position; when the charging control unit sends a high level signal to the switching switch, the switching switch performs a switching action; or when the charging control unit sends a high level signal to the switching switch, the switching switch maintains an initial position; when the charging control unit sends a low level signal to the switching switch, the switching switch performs a switching action.

[0012] In an improved solution, the charging control unit and the conversion switch communicate with each other via LIN communication.

[0013] In an improved solution, after charging is completed in step S31, the power supply of the conversion switch is stopped and the charging control unit enters a standby state, thereby reducing energy consumption.

[0014] In an improved solution, after charging is completed in step S32, the charging control unit controls the conversion switch to reset to an initial state, and then stops the power supply of the conversion switch, and the charging control unit enters a standby state, thereby reducing energy consumption.

[0015] In an improved solution, in step S1, when the vehicle is in a parked state, the charging port of the vehicle can be inserted into the charging gun of the charging pile to ensure safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of Example 1 of a control method of a series-parallel conversion switch of a battery pack module for a new energy vehicle; Figure 2 This is a flow chart of Example 2 of a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle; Figure 3 The present invention is a flow chart of Example 3 of a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle. DETAILED DESCRIPTION

[0017] It should be understood by those skilled in the art that the following embodiments are only used to explain the technical principles of the embodiments of the present application and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art may adjust them as needed to adapt to specific application scenarios.

[0018] In the description of the following embodiments, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0019] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0020] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 See also Figure 1 , a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle provided in Embodiment 1 of the present invention is applied to a new energy vehicle, wherein the new energy vehicle has a charging port, a charging control unit, a charging circuit and a battery pack module, wherein the charging circuit is used to connect the charging port and the battery pack module, wherein the battery pack module includes a first battery pack and a second battery pack, wherein the charging circuit is provided with a conversion switch for controlling the first battery pack and the second battery pack to be connected in series or in parallel with each other, and the charging control unit is electrically connected to the conversion switch; The steps include: S1. When the charging port of the vehicle is plugged into the charging gun of the charging pile, the charging control unit is awakened, and the conversion switch is powered and in the initial position; S2. The charging control unit detects the maximum charging voltage corresponding to the charging pile and compares it with the working voltage of the vehicle's battery pack module: S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to maintain the initial position, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and then enters S31; S22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to perform a switching action, that is, to change the series-parallel state of the first battery pack and the second battery pack of the battery pack module, and then the charging control unit detects the highest charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, S32 is executed; if they are different, S23 is executed; S23, the charging control unit controls the conversion switch to reset to the initial state, and at the same time, the charging control unit issues an alarm message indicating charging incompatibility; S31, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; S32, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed, and then the charging control unit controls the conversion switch to reset to the initial state.

[0022] The above scheme detects the maximum charging voltage of the charging pile through the charging control unit, so that when the maximum charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, it means that the charging pile and the battery pack module are currently compatible, so the charging control unit controls the conversion switch to maintain the initial position, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; and when the maximum charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, it means that the charging pile and the battery pack module are currently incompatible, and the charging control unit controls the conversion switch to perform a switching action, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is changed, and then the charging control unit detects the maximum charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; if they are different, the electrical control unit controls the conversion switch to reset to the initial state, and the charging control unit issues an alarm message of charging incompatibility. Compared with the existing technology, the above solution enables new energy vehicles to automatically adapt to two different charging voltages, effectively improving versatility.

[0023] In this embodiment, the conversion switch has an electric actuator, and the electric actuator controls the first battery group and the second battery group to be connected in series or in parallel with each other through mechanical movement, and the electric actuator controls the first battery group and the second battery group to be connected in series or in parallel with each other through mechanical movement, and has good reliability. It should be noted that the principle of how the electric actuator of the conversion switch specifically realizes the connection of the first battery group and the second battery group in series or in parallel with each other belongs to the prior art, and can be referred to the patent application document with application number 2024218258680, which will not be repeated here. The electric actuator of the conversion switch of the present application is the actuator in the patent application document, and the charging control unit of the present application is the controller in the patent application. In addition, the conversion switch is preferably powered by a low-voltage power supply inside the vehicle to ensure that the electric actuator can work normally.

[0024] It should be noted that the relationship between the initial state of the conversion switch and the series connection or parallel connection of the first battery group and the second battery group can be set as needed. For example, in this embodiment, when the conversion switch is in the initial state, the corresponding first battery group and the second battery group are connected in parallel, and the battery pack module is charged with an operating voltage of 400V; after the conversion switch performs the switching action, the corresponding first battery group and the second battery group are connected in series, and the battery pack module is charged with an operating voltage of 800V.

[0025] In addition, as an improvement to step S1, the charging port of the vehicle can only be inserted into the charging gun of the charging pile when the vehicle is in a parked state, thereby ensuring safety.

[0026] Example 2 See also Figure 2 , a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle provided in embodiment 2 of the present invention is applied to a new energy vehicle, wherein the new energy vehicle has a charging port, a charging control unit, a charging circuit and a battery pack module, wherein the charging circuit is used to connect the charging port and the battery pack module, wherein the battery pack module includes a first battery pack and a second battery pack, wherein the charging circuit is provided with a conversion switch for controlling the first battery pack and the second battery pack to be connected in series or in parallel with each other, and the charging control unit is electrically connected to the conversion switch; The steps include: S1. When the charging port of the vehicle is plugged into the charging gun of the charging pile, the charging control unit is awakened, and the conversion switch is powered and in the initial position; S2. The charging control unit detects the maximum charging voltage corresponding to the charging pile and compares it with the working voltage of the vehicle's battery pack module: S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit sends a low-level signal to the conversion switch, and the conversion switch maintains the initial position after receiving the low-level signal, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and then enters S31; S22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit sends a high-level signal to the conversion switch, and the conversion switch performs a switching action after receiving the high-level signal, that is, changes the series-parallel state of the first battery pack and the second battery pack of the battery pack module, and then the charging control unit detects the highest charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, execute S32; if they are different, execute S23; S23, the charging control unit controls the conversion switch to reset to the initial state, and at the same time, the charging control unit issues an alarm message indicating charging incompatibility; S31, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; S32, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed, and then the charging control unit controls the conversion switch to reset to the initial state.

[0027] Example 3 See also Figure 3, a control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle provided in embodiment 3 of the present invention is applied to a new energy vehicle, wherein the new energy vehicle has a charging port, a charging control unit, a charging circuit and a battery pack module, wherein the charging circuit is used to connect the charging port and the battery pack module, wherein the battery pack module includes a first battery pack and a second battery pack, wherein the charging circuit is provided with a conversion switch for controlling the first battery pack and the second battery pack to be connected in series or in parallel with each other, and the charging control unit is electrically connected to the conversion switch; The steps include: S1. When the charging port of the vehicle is plugged into the charging gun of the charging pile, the charging control unit is awakened, and the conversion switch is powered and in the initial position; S2. The charging control unit detects the maximum charging voltage corresponding to the charging pile and compares it with the working voltage of the vehicle's battery pack module: S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit sends an instruction to the conversion switch to maintain the initial position through LIN communication, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and then enters S31; S22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit sends a command to execute a switching action to the conversion switch through LIN communication, that is, to change the series-parallel state of the first battery pack and the second battery pack of the battery pack module, and then the charging control unit detects the highest charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, S32 is executed; if they are different, S23 is executed; S23, the charging control unit controls the conversion switch to reset to the initial state, and at the same time, the charging control unit issues an alarm message indicating charging incompatibility; S31, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; S32, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed, and then the charging control unit controls the conversion switch to reset to the initial state.

[0028] It should be noted that, in the description of the present application, the terms "inside", "outside", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application; all directional indications (such as up, down, left, right, front, back, inside, and outside) are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0029] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0030] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A control method for a series-parallel conversion switch of a battery pack module for a new energy vehicle, applied to a new energy vehicle, wherein the new energy vehicle has a charging port, a charging control unit, a charging circuit and a battery pack module, wherein the charging circuit is used to connect the charging port and the battery pack module, wherein the battery pack module includes a first battery pack and a second battery pack, wherein the charging circuit is provided with a conversion switch for controlling the first battery pack and the second battery pack to be connected in series or in parallel with each other, and wherein the charging control unit is electrically connected to the conversion switch; It is characterized in that The steps include: S1. When the charging port of the vehicle is plugged into the charging gun of the charging pile, the charging control unit is awakened, and the conversion switch is powered and in the initial position; S2. The charging control unit detects the maximum charging voltage corresponding to the charging pile and compares it with the working voltage of the vehicle's battery pack module: S21, when the highest charging voltage of the charging pile is the same as the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to maintain the initial position, that is, the series-parallel state of the first battery pack and the second battery pack of the battery pack module is not changed, and then enters S31; S22, when the highest charging voltage of the charging pile is different from the working voltage of the battery pack module of the vehicle, the charging control unit controls the conversion switch to perform a switching action, that is, to change the series-parallel state of the first battery pack and the second battery pack of the battery pack module, and then the charging control unit detects the highest charging voltage corresponding to the charging pile again and compares it with the working voltage of the battery pack module of the vehicle. If they are the same, S32 is executed; if they are different, S23 is executed; S23, the charging control unit controls the conversion switch to reset to the initial state, and at the same time, the charging control unit issues an alarm message indicating charging incompatibility; S31, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed; S32, the charging gun of the charging port charges the battery pack module of the vehicle through the charging circuit until the charging is completed, and then the charging control unit controls the conversion switch to reset to the initial state.

2. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 is characterized in that: The changeover switch has an electric actuator, which controls the first battery group and the second battery group to be connected in series or in parallel through mechanical movement.

3. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 is characterized in that: The charging control unit and the switching switch communicate with each other through a level signal: when the charging control unit sends a low level signal to the switching switch, the switching switch maintains an initial position; when the charging control unit sends a high level signal to the switching switch, the switching switch performs a switching action; or when the charging control unit sends a high level signal to the switching switch, the switching switch maintains an initial position; when the charging control unit sends a low level signal to the switching switch, the switching switch performs a switching action.

4. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 is characterized in that: The charging control unit and the conversion switch communicate with each other via LIN communication.

5. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 is characterized in that: In step S31, after charging is completed, the power supply of the conversion switch is stopped, and the charging control unit enters a standby state.

6. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 or 5, characterized in that: In step S32, after charging is completed, the charging control unit controls the conversion switch to reset to the initial state, and then stops the power supply of the conversion switch, and the charging control unit enters the standby state.

7. The control method of the series-parallel conversion switch of the battery pack module for new energy vehicles according to claim 1 is characterized in that: In step S1, when the vehicle is in a parked state, the charging port of the vehicle can be plugged into the charging gun of the charging pile.

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