Polarization current elimination method and charging circuit

Abstract

The application provides a polarization current elimination method and a charging circuit. The polarization current elimination method comprises the following steps: when a power battery is fast-charged based on a preset power, it is detected whether a first signal is received; when the first signal is received, the power battery is controlled to perform negative pulse discharge, so as to input a negative pulse current to a target load, wherein the first signal is generated when a polarization value of the power battery reaches a starting depolarization function threshold; when a second signal is received, the power battery is controlled to stop inputting the negative pulse current to the vehicle-mounted motor or the load, and the second signal is generated when the polarization value of the power battery reaches an exiting depolarization function threshold. The application can reduce the polarization degree of the battery, thereby improving the safety of the battery and prolonging the service life of the battery in a large-power fast-charging scene. Meanwhile, the application can reduce the polarization degree of the battery without the need of increasing an additional capacitor to reduce the polarization degree of the battery, and therefore, the application also has the advantage of lower cost.

Description

Technical Field

[0001] This application relates to the field of charging equipment, and more specifically, to a polarization current elimination method and a charging circuit. Background Technology

[0002] Currently, charging power batteries at a fast charging current exceeding a certain rate can easily exacerbate battery polarization (deviating from the equilibrium potential), gradually leading to gas evolution and lithium deposition within the battery cells, reducing battery life, and in severe cases, causing the risk of battery thermal runaway. Summary of the Invention

[0003] The purpose of this application is to provide a polarization current elimination method and charging circuit to reduce battery polarization, thereby improving battery safety and extending battery life in high-power fast charging scenarios. Furthermore, this application eliminates the need for bidirectional charging piles or additional capacitors to reduce battery polarization, thus offering the advantage of lower cost.

[0004] In a first aspect, the present invention provides a method for eliminating polarization current, the method comprising:

[0005] When the power battery is fast-charging based on a preset power, detect whether the first signal is received;

[0006] When the first signal is received, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the target load and make the target load perform work based on the negative pulse current. The first signal is generated when the polarization value of the power battery reaches the threshold for starting the depolarization function.

[0007] The system detects whether a second signal is received. When the second signal is received, it controls the power battery to stop inputting the negative pulse current to the vehicle motor or the load. The second signal is generated when the polarization value of the power battery reaches the threshold for exiting the depolarization function.

[0008] In the first aspect of this application, when the power battery is fast-charging at a preset power, it detects whether a first signal is received. Then, when the polarization value of the power battery reaches the threshold for activating the depolarization function, it controls the power battery to perform negative pulse discharge, inputting a negative pulse current to the target load. This causes the target load to perform work based on the negative pulse current, thereby eliminating the polarization current and ultimately reducing the degree of battery polarization. On the other hand, when the polarization value of the power battery reaches the threshold for exiting the depolarization function, it can automatically control the power battery to stop inputting negative pulse current to the vehicle motor or load.

[0009] Compared with existing technologies, this application can improve battery safety and extend battery life in high-power fast charging scenarios. Furthermore, this application does not require bidirectional charging piles to reduce battery polarization, nor does it require adding extra capacitors to reduce battery polarization; therefore, this application also has the advantage of lower cost.

[0010] In a first aspect of this application, as an optional implementation, the target load includes an on-board motor. In this optional implementation, polarization current can be eliminated by the on-board motor.

[0011] In a first aspect of this application, as an optional implementation, controlling the power battery to perform negative pulse discharge to input a negative pulse current to a target load, and causing the target load to perform work based on the negative pulse current, includes:

[0012] Obtain the acceptable power range of the vehicle motor;

[0013] Based on the acceptable power range of the vehicle motor, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the vehicle motor, and the vehicle motor performs work based on the negative pulse current.

[0014] This optional implementation can input the negative pulse current to the vehicle motor based on the acceptable power range of the vehicle motor, thereby avoiding the negative pulse current input to the vehicle motor from exceeding the power tolerance range of the vehicle motor, thus reducing the probability of the vehicle motor being damaged due to excessive negative pulse current.

[0015] In a first aspect of this application, as an optional implementation, the target load includes an on-board heater. In this optional implementation, the on-board heater can eliminate polarization current.

[0016] In an optional implementation, controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes:

[0017] Obtain the acceptable power range of the vehicle-mounted heater;

[0018] Based on the acceptable power range of the vehicle heater, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the vehicle heater, and to make the vehicle heater base

[0019] Work is done on the negative pulse current.

[0020] In this optional embodiment, by obtaining the acceptable power range of the on-board heater, and then controlling the power battery to perform negative pulse discharge based on the acceptable power range of the on-board heater, in order to provide power to the vehicle...

[0021] The input of the onboard heater is a negative pulse current that the onboard heater can withstand, thereby reducing the probability that the onboard heater will be damaged due to excessive negative pulse current.

[0022] In the first aspect of this application, as an optional implementation, the target load is an external electrical device.

[0023] In this optional embodiment, polarization current can also be eliminated by using an external electrical device.

[0024] In a first aspect of this application, as an optional implementation, the control power battery performs a negative pulse discharge to input a negative pulse current to the target load, and the target load is based on the...

[0025] The negative pulse current performs work, including:

[0026] Obtain the acceptable power range of the external electrical equipment;

[0027] Based on the acceptable power range of the external electrical device, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the external electrical device, and the external electrical device performs work based on the negative pulse current.

[0028] This optional implementation can input the negative pulse current to the external electrical device based on the acceptable power range of the external electrical device, thereby avoiding the negative pulse current input to the external electrical device from exceeding the power tolerance range of the external electrical device, and thus reducing the probability of the external electrical device being damaged due to excessive negative pulse current.

[0029] In a first aspect of this application, as an optional implementation, before controlling the power battery to stop inputting the negative pulse current to the vehicle motor or the load, the method further includes:

[0030] If the current charging stage of the power battery is determined to be the positive current charging stage, then the control is executed to stop the power battery from inputting the negative pulse current to the vehicle motor or the load.

[0031] This optional implementation can determine whether the current charging stage of the power battery is a positive current charging stage, and then when the current charging stage of the power battery is a positive current charging stage, it can control the power battery to stop inputting negative pulse current to the vehicle motor or load, thereby ensuring that the positive current charging stage can be executed normally.

[0032] In a first aspect of this application, as an optional implementation, the polarization value of the power battery is one of a current value, a voltage value, and a resistance value, wherein when the polarization value of the power battery is a current value, the polarization threshold is a current value; when the polarization value of the power battery is a voltage value, the polarization threshold is a voltage value; and when the resistance value of the power battery is a voltage value, the polarization threshold is a resistance value.

[0033] This optional implementation can use one of the parameters—current value, voltage value, and resistance value—as the polarization value of the power battery.

[0034] Secondly, the present invention provides a charging circuit, the charging circuit including a vehicle control module, a DC power supply, a main negative relay and a power battery, wherein the DC power supply is electrically connected to the power battery for charging the power battery, and the power battery is electrically connected to a target load through the main negative relay.

[0035] Furthermore, the vehicle control module is connected to the power battery and the main negative relay, wherein the vehicle control module is used to execute the polarization current elimination method of the first aspect of this application.

[0036] In the second aspect of this application, the vehicle control module can execute a polarization current elimination method, thereby controlling the power battery to perform negative pulse discharge, inputting a negative pulse current to the vehicle motor, and causing the target load to perform work based on the negative pulse current. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic flowchart of a polarization current elimination method improved in an embodiment of this application;

[0039] Figure 2 This is a schematic diagram of a charging circuit provided in an embodiment of this application. Detailed Implementation

[0040] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0041] The purpose of this application is to provide a polarization current elimination method and charging circuit to reduce battery polarization, thereby improving battery safety and extending battery life in high-power fast charging scenarios. Furthermore, this application eliminates the need for bidirectional charging piles or additional capacitors to reduce battery polarization, thus offering the advantage of lower cost.

[0042] Please see Figure 1 , Figure 1 This is a schematic flowchart of a polarization current elimination method improved in an embodiment of this application. Figure 1 As shown, the polarization current elimination method in this application includes the following steps:

[0043] 101. When the power battery is fast-charging based on a preset power, detect whether the first signal is received;

[0044] 102. When the first signal is received, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the target load and make the target load perform work based on the negative pulse current. The first signal is generated when the polarization value of the power battery reaches the threshold for starting the depolarization function.

[0045] 103. Detect whether the second signal is received. When the second signal is received, control the power battery to stop inputting negative pulse current to the vehicle motor or load. The second signal is generated when the polarization value of the power battery reaches the threshold for exiting the depolarization function.

[0046] In this embodiment, when the power battery is fast-charging at a preset power, it detects whether a first signal is received. Then, when the polarization value of the power battery reaches the threshold for activating the depolarization function, it controls the power battery to perform negative pulse discharge, inputting a negative pulse current to the target load. This causes the target load to perform work based on the negative pulse current, thereby eliminating the polarization current and ultimately reducing the degree of battery polarization. Conversely, when the polarization value of the power battery reaches the threshold for exiting the depolarization function, it automatically controls the power battery to stop inputting negative pulse current to the vehicle motor or load.

[0047] Compared with existing technologies, this application can improve battery safety and extend battery life in high-power fast charging scenarios. Furthermore, this application does not require bidirectional charging piles to reduce battery polarization, nor does it require adding extra capacitors to reduce battery polarization; therefore, this application also has the advantage of lower cost.

[0048] In this embodiment of the application, for step 101, optionally, it can be determined whether the power battery is fast-charging based on a preset power based on the voltage or current output by the power supply, or it can be determined directly by obtaining the operating voltage or current of the power battery. Further, the preset power refers to the power required for the power battery to fast-charge, which is typically above 50kW.

[0049] In this embodiment of the application, as an optional implementation, the target load includes an on-board motor. In this optional implementation, the polarization current can be eliminated by the on-board motor.

[0050] In this embodiment of the application, as an optional implementation, controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes:

[0051] Obtain the acceptable power range of the vehicle motor;

[0052] Based on the acceptable power range of the vehicle motor, the power battery is controlled to perform negative pulse discharge to input negative pulse current to the vehicle motor, and the vehicle motor performs work based on the negative pulse current.

[0053] Since the rated power or upper limit of the on-board motor of each vehicle is different, it is necessary to adapt to this difference. This optional implementation can input negative pulse current to the on-board motor based on the acceptable power range of the on-board motor, thereby avoiding the negative pulse current input to the on-board motor from exceeding the power tolerance range of the on-board motor, thereby reducing the probability of the on-board motor being damaged due to excessive negative pulse current.

[0054] In this embodiment of the application, as an optional implementation, the target load includes an on-board heater. In this optional implementation, the polarization current can be eliminated by using an on-board heater.

[0055] In an optional implementation, the power battery is further controlled to perform negative pulse discharge to input a negative pulse current to the target load, and the target load performs work based on the negative pulse current, including the following sub-steps:

[0056] Obtain the acceptable power range for the vehicle heater;

[0057] Based on the acceptable power range of the vehicle heater, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the vehicle heater, and the vehicle heater performs work based on the negative pulse current.

[0058] In this optional embodiment, by obtaining the acceptable power range of the vehicle heater, and then controlling the power battery to perform negative pulse discharge based on the acceptable power range of the vehicle heater, a negative pulse current that the vehicle heater can withstand is input to the vehicle heater, thereby reducing the probability that the vehicle heater will be damaged due to excessive negative pulse current.

[0059] In this embodiment of the application, as an optional implementation, the target load is an external electrical device. In this optional implementation, polarization current can also be eliminated by using an external electrical device.

[0060] In this embodiment of the application, as an optional implementation, controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes:

[0061] Obtain the acceptable power range for external electrical equipment;

[0062] Based on the acceptable power range of the external electrical equipment, the power battery is controlled to perform negative pulse discharge to input negative pulse current to the external electrical equipment, and the external electrical equipment performs work based on the negative pulse current.

[0063] This optional implementation can input a negative pulse current to the external electrical device based on the acceptable power range of the external electrical device, thereby avoiding the negative pulse current input to the external electrical device from exceeding the power tolerance range of the external electrical device, and thus reducing the probability of the external electrical device being damaged due to excessive negative pulse current.

[0064] In this optional embodiment, the external electrical device can be a charging station. Alternatively, the acceptable power range of the external electrical device can be obtained by the vehicle after a communication connection is established between the vehicle and the external electrical device.

[0065] In this embodiment of the application, as an optional implementation, before controlling the power battery to stop inputting negative pulse current to the vehicle motor or load, the method of this embodiment of the application further includes the following steps:

[0066] If the current charging stage of the power battery is determined to be the positive current charging stage, then the power battery is controlled to stop inputting negative pulse current to the vehicle motor or load.

[0067] This optional implementation can determine whether the current charging stage of the power battery is a positive current charging stage, and then when the current charging stage of the power battery is a positive current charging stage, it can control the power battery to stop inputting negative pulse current to the vehicle motor or load, thereby ensuring that the positive current charging stage can be executed normally.

[0068] In an embodiment of this application, as an optional implementation, the polarization value of the power battery is one of the following: current value, voltage value, and resistance value. When the polarization value of the power battery is current value, the polarization threshold is current value; when the polarization value of the power battery is voltage value, the polarization threshold is voltage value; and when the resistance value of the power battery is voltage value, the polarization threshold is resistance value.

[0069] This optional implementation can use one of the parameters, namely current value, voltage value, and resistance value, as the polarization value of the power battery. Different vehicle models may use different parameters to measure whether the power battery is currently polarized. For example, when the power battery is polarized, it generates polarization resistance, and the polarization resistance can be used as the polarization value of the power battery.

[0070] In addition, this application embodiment also provides a charging circuit, please refer to... Figure 2 , Figure 2 This is a schematic diagram of a charging circuit provided in an embodiment of this application. Figure 2 As shown, the charging circuit includes a vehicle control module, a DC power supply, a main negative relay, and a power battery. The DC power supply is electrically connected to the power battery and is used to charge the power battery. The power battery is electrically connected to the target load through the main negative relay.

[0071] Furthermore, the vehicle control module is connected to the power battery and the main and negative relays, wherein the vehicle control module is used to execute the polarization current elimination method of the first aspect of this application.

[0072] In this embodiment of the application, the vehicle control module can execute the polarization current elimination method, thereby controlling the power battery to perform negative pulse discharge, so as to input negative pulse current to the vehicle motor and make the target load perform work based on the negative pulse current.

[0073] In this embodiment of the application, the charging circuit further includes a voltage acquisition sensor, a current acquisition sensor, and a resistance acquisition sensor. The voltage acquisition sensor can acquire the operating voltage of the power battery, the current acquisition sensor can acquire the operating current of the power battery, and the resistance acquisition sensor can acquire the internal resistance of the power battery.

[0074] In this embodiment, the charging circuit further includes a fast-charging relay, which is electrically connected to a DC power supply. When the fast-charging relay is closed, the DC power supply charges the power battery in fast-charging mode. Furthermore, by determining whether the fast-charging relay is closed, it is possible to determine whether the power battery is in fast-charging mode.

[0075] In this embodiment, the charging circuit further includes a pre-charging resistor and a pre-charging relay, wherein the pre-charging resistor and the pre-charging relay are electrically connected to form a pre-charging branch for pre-charging the power battery. Further, the charging circuit also includes a main positive relay, wherein when the power battery is in a charging state, the main positive relay is in a closed state, allowing the current output from the DC power supply to flow to the power battery; conversely, when the main positive relay is in a closed state, the pre-charging relay is in an open state.

[0076] In this application embodiment, optionally, the vehicle control module may refer to the vehicle's electronic control unit. For details regarding the specific structure of the vehicle's electronic control unit, please refer to the prior art.

[0077] In the embodiments of this application, specifically, as shown in the example Figure 2 As shown, the charging circuit can be electrically connected to target loads such as vehicle motors (electric motors) and high-voltage loads. When it is necessary to input a negative pulse current to the target load, the vehicle control module can control the main negative relay to be in a closed state and the main positive relay to be in an open state.

[0078] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0079] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0080] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0081] It should be noted that if the function is implemented as a software module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0082] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0083] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method of eliminating polarization current, characterized by, The method includes: When the power battery is fast-charging based on a preset power, detect whether the first signal is received; When the first signal is received, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the target load and make the target load perform work based on the negative pulse current. The first signal is generated when the polarization value of the power battery reaches the threshold for starting the depolarization function. The system detects whether a second signal is received. When the second signal is received, it controls the power battery to stop inputting the negative pulse current to the target load. The second signal is generated when the polarization value of the power battery reaches the threshold for exiting the depolarization function. The target load includes an onboard motor; The method of controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes: Obtain the acceptable power range of the vehicle motor; Based on the acceptable power range of the vehicle motor, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the vehicle motor, and the vehicle motor performs work based on the negative pulse current.

2. A method of eliminating polarization current, characterized by, The method includes: When the power battery is fast-charging based on a preset power, detect whether the first signal is received; When the first signal is received, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the target load and make the target load perform work based on the negative pulse current. The first signal is generated when the polarization value of the power battery reaches the threshold for starting the depolarization function. The system detects whether a second signal is received. When the second signal is received, it controls the power battery to stop inputting the negative pulse current to the target load. The second signal is generated when the polarization value of the power battery reaches the threshold for exiting the depolarization function. The target load includes an on-board heater; The method of controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes: Obtain the acceptable power range of the vehicle-mounted heater; Based on the acceptable power range of the vehicle heater, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the vehicle heater, and the vehicle heater performs work based on the negative pulse current.

3. A method of eliminating polarization current, characterized by, The method includes: When the power battery is fast-charging based on a preset power, detect whether the first signal is received; When the first signal is received, the power battery is controlled to perform negative pulse discharge to input a negative pulse current to the target load and make the target load perform work based on the negative pulse current. The first signal is generated when the polarization value of the power battery reaches the threshold for starting the depolarization function. The system detects whether a second signal is received. When the second signal is received, it controls the power battery to stop inputting the negative pulse current to the target load. The second signal is generated when the polarization value of the power battery reaches the threshold for exiting the depolarization function. The target load is an external electrical device; The method of controlling the power battery to perform negative pulse discharge to input a negative pulse current to the target load, and causing the target load to perform work based on the negative pulse current, includes: Obtain the acceptable power range of the external electrical equipment; Based on the acceptable power range of the external electrical device, the power battery is controlled to perform negative pulse discharge to input the negative pulse current to the external electrical device, and the external electrical device performs work based on the negative pulse current.

4. The method according to any one of claims 1 to 3, characterized in that, Before controlling the power battery to stop inputting the negative pulse current to the target load, the method further includes: Determine whether the current charging stage of the power battery is a positive current charging stage. If the current charging stage of the power battery is the positive current charging stage, then execute the control to stop the power battery from inputting the negative pulse current to the target load.

5. The method according to any one of claims 1 to 3, wherein The polarization value of the power battery is one of the following: current value, voltage value, and resistance value. When the polarization value of the power battery is current value, the depolarization function threshold is current value; when the polarization value of the power battery is voltage value, the depolarization function threshold is voltage value; and when the polarization value of the power battery is resistance value, the depolarization function threshold is resistance value.

6. A charging circuit, characterized by comprising: The charging circuit includes a vehicle control module, a DC power supply, a main negative relay, and a power battery. The DC power supply is electrically connected to the power battery and is used to charge the power battery. The power battery is electrically connected to the target load through the main negative relay. Furthermore, the vehicle control module is connected to the power battery and the main negative relay, wherein the vehicle control module is used to execute the polarization current elimination method according to any one of claims 1-3.

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