Battery equalization system and energy storage system

Abstract

The utility model provides a battery equalization system and an energy storage system, and relates to the technical field of batteries. The battery equalization system comprises a battery pack, a battery management system, an equalization unit and a controller, the battery pack comprises a box body, a cover body and a plurality of battery cells, and one battery cell corresponds to one balancing unit; the battery management system is connected with the plurality of battery cells, communicates with the controller, and is used for determining the battery cells to be equalized and generating an equalization control instruction; each balancing unit comprises an emitter and a receiver, the emitter and the receiver are oppositely arranged and are in magnetic induction connection, the receiver is connected with one corresponding battery cell, the emitter is arranged on the inner wall of the cover body opposite to one battery cell, and the emitter is connected with auxiliary equipment; and the controller is arranged on the inner wall of the cover body, is electrically connected with the emitter and is used for controlling the emitter to be selectively connected with the auxiliary equipment so as to control the to-be-balanced battery cells to output electric energy or input electric energy, and balance of the multiple battery cells is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of batteries, and in particular, to a battery balancing system and an energy storage system. Background Art

[0002] With the technological iteration in the energy storage system, products with large-sized cells and large capacities are gradually increasing, and the consistency problem of the battery system has become increasingly serious.

[0003] In the related art, the battery system inconsistency is reduced through balancing technologies, including passive balancing and active balancing. However, both of the above two balancing technologies use the battery management system to balance the cells through physical wiring harnesses. Limited by the wire diameter of the wiring harness and the heat generation of the battery management system, problems such as poor balancing effect and low efficiency occur. Summary of the Utility Model

[0004] The present disclosure provides a battery balancing system and an energy storage system, which at least overcome to a certain extent the problems of poor balancing effect and low efficiency of the balancing technology for cells in the related art.

[0005] Other features and advantages of the present disclosure will become apparent through the following detailed description, or will be partially learned through the practice of the present disclosure.

[0006] According to one aspect of the present disclosure, a battery balancing system is provided, including: a battery pack, a battery management system, a balancing unit, and a controller;

[0007] Wherein, the battery pack includes a box body, a cover body, and a plurality of cells in the box body, and one cell corresponds to one balancing unit;

[0008] The battery management system is connected to the plurality of cells, and the battery management system communicates with the controller, and is used to determine the cells to be balanced and generate a balancing control instruction;

[0009] Each balancing unit includes a transmitter and a receiver, the transmitter and the receiver are oppositely arranged and magnetically inductively connected, the receiver is connected to a corresponding one of the cells, the transmitter is arranged on the inner wall of the cover body opposite to the one cell, and the transmitter is connected to an auxiliary device;

[0010] The controller is arranged on the inner wall of the cover body, and the controller is electrically connected to the transmitter, and is used to control the transmitter to selectively connect to the auxiliary device, so as to control the cells to be balanced to output or input electric energy, and realize the balancing of a plurality of cells.

[0011] In an embodiment of the present disclosure, the cover body is provided with a wire column, the controller is connected to the wire column through a wiring harness, and the wire column is connected to a power supply.

[0012] In one embodiment of the present disclosure, the controller includes a filtering circuit, the filtering circuit is electrically connected to the auxiliary device, and the auxiliary device includes a charging device and an electrical load;

[0013] A plurality of the transmitters are connected to a data bus, and the data bus is electrically connected to the filtering circuit through a first loop conduction switch.

[0014] In one embodiment of the present disclosure, each transmitter includes a transmitting coil and a second loop conduction switch connected in series, the second loop conduction switch is connected to the data bus, and the control end of the second loop conduction switch is connected to the controller.

[0015] In one embodiment of the present disclosure, the transmitter further includes a power amplifier connected in series with the transmitting coil, and the power amplifier includes a resonant capacitor, an inverter circuit, and a chopper circuit.

[0016] In one embodiment of the present disclosure, the transmitter further includes a first selection switch; the number of turns of the transmitting coil is greater than or equal to 2; the transmitting coil is electrically connected to the resonant capacitor through the first selection switch, and the control end of the first selection switch is connected to the controller.

[0017] In one embodiment of the present disclosure, the receiver includes a receiving coil and a third loop conduction switch connected in series, the third loop conduction switch is connected to the corresponding battery cell, and the control end of the third loop conduction switch is electrically connected to the controller.

[0018] In one embodiment of the present disclosure, the receiver further includes a resonant circuit and a rectifying circuit, and the resonant circuit and the rectifying circuit are connected in series with the receiving coil.

[0019] In one embodiment of the present disclosure, the controller communicates with the battery management system through power;

[0020] The controller communicates with the transmitter through power;

[0021] The transmitter communicates with the receiver wirelessly.

[0022] According to another aspect of the present disclosure, there is also provided an energy storage system including the battery equalization system provided in the above embodiments.

[0023] In an embodiment of the present disclosure, the battery equalization system includes a battery pack, a battery management system, an equalization unit, and a controller; the battery pack includes a box body, a cover body, and a plurality of battery cells in the box body, and one battery cell corresponds to one equalization unit; the battery management system is connected to the plurality of battery cells, and the battery management system communicates with the controller to determine the battery cells to be equalized and generate an equalization control instruction; each equalization unit includes a transmitter and a receiver, the transmitter and the receiver are oppositely arranged and magnetically inductively connected, the receiver is connected to a corresponding battery cell, the transmitter is arranged on the inner wall of the cover body opposite to a battery cell, and the transmitter is connected to an auxiliary device; the controller is arranged on the inner wall of the cover body, the input end of the controller is electrically connected to the battery management system, and the controller is electrically connected to the transmitter to control the transmitter to selectively connect to the auxiliary device according to the equalization control instruction generated by the battery management system, so as to control the battery cell to be equalized to output or input electric energy, and realize the equalization of a plurality of battery cells. On the one hand, the present disclosure can realize the wireless equalization function, reduce the wire harness connection, set the equalization current as required, and improve the equalization efficiency; on the other hand, the present disclosure can not change the original arrangement of the battery cells, does not need to change the layout of the battery management system of the product, has better compatibility, and releases the equalization function from the BMS, reduces the computing power of the BMS and the complexity of the equalization strategy, and improves the focus of the BMS.

[0024] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings without creative efforts based on these drawings.

[0026] Figure 1 A schematic structural diagram showing an exemplary application scenario of an energy storage system provided in an embodiment of the present disclosure.

[0027] Figure 2 A schematic structural diagram showing a battery equalization system provided in an embodiment of the present disclosure.

[0028] Figure 3 An exploded view showing a battery equalization system provided in an embodiment of the present disclosure.

[0029] Figure 4 A schematic internal structure diagram showing a battery equalization system provided in an embodiment of the present disclosure.

[0030] Figure 5 A schematic internal structure diagram showing a cover body provided in an embodiment of the present disclosure.

[0031] Figure 6 The schematic diagram showing a controller controlling a transmitter provided by an embodiment of the present disclosure.

[0032] Figure 7 The schematic structural diagram of a transmitter provided by an embodiment of the present disclosure.

[0033] Figure 8 The schematic diagram showing a controller controlling a receiver provided by an embodiment of the present disclosure.

[0034] Figure 9 The schematic structural diagram of a receiver provided by an embodiment of the present disclosure.

[0035] Figure 10 The control logic diagram of a battery equalization system provided by an embodiment of the present disclosure.

[0036] Among them, the reference numerals are explained as follows:

[0037] 110, energy storage device; 120, high-voltage cable; 130, first power conversion device; 140, second power conversion device;

[0038] 200, battery equalization system;

[0039] 210, box body; 211, lead hole;

[0040] 220, cover body; 221, wire column; 222, fixing member;

[0041] 230, battery cell; 231, pole column;

[0042] 240, bus bar;

[0043] 250, equalization unit; 251, receiver; 2511, receiving coil; 2512, resonant circuit; 2513, rectifying circuit; 2514, third loop conduction switch; 252, transmitter; 2521, transmitting coil; 2522, resonant capacitor; 2523, inverter circuit; 2524, chopper circuit; 2525; second loop conduction switch; 2526, first selection switch;

[0044] 260, controller; 261, wire harness; 262, first loop conduction switch. Detailed implementation manners

[0045] Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be more thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0046] The terms "first" and "second" in the text are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise clearly specified.

[0047] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" should be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a communication connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0048] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0049] Since the energy required by people has strong temporality and spatiality, in order to rationally utilize energy and improve the energy utilization rate, it is necessary to store one form of energy in the same or converted into another form of energy through a medium or device and release it in a specific energy form based on future application needs. Currently, the main way to generate green electric energy is to develop green energy such as photovoltaic and wind power to replace fossil energy.

[0050] At present, the generation of green electricity generally relies on photovoltaics, wind power, water potential, etc. However, problems such as strong intermittency and large volatility are common in wind energy and solar energy, which can cause grid instability. During peak electricity consumption, there is not enough electricity, while during off-peak electricity consumption, there is too much electricity. The unstable voltage can also damage the power. Therefore, the problems of "abandoning wind and light" may be caused due to insufficient electricity demand or insufficient grid acceptance capacity. To solve these problems, energy storage is required. That is, electrical energy is converted into other forms of energy through physical or chemical means and stored, and the energy is converted back into electrical energy and released when needed. Simply put, energy storage is similar to a large "portable power bank". When photovoltaics and wind energy are sufficient, electrical energy is stored, and the stored electricity is released when needed.

[0051] Taking electrochemical energy storage as an example, the present disclosure provides an energy storage device. A group of chemical batteries are provided inside the energy storage device. It mainly uses the chemical elements in the batteries as the energy storage medium. The charge and discharge process is accompanied by chemical reactions or changes of the energy storage medium. Simply put, the electrical energy generated by wind energy and solar energy is stored in the chemical batteries, and the stored electricity is released when the external electricity usage reaches the peak, or transferred to places with a shortage of electricity for further use.

[0052] At present, the application scenarios of energy storage (i.e., energy storage) are relatively extensive, including power generation side energy storage, grid side energy storage, and user side energy storage, etc. The types of corresponding energy storage devices include:

[0053] (1) Large-scale energy storage power stations applied on the side of wind power and photovoltaic power stations can assist renewable energy power generation to meet grid connection requirements and improve the utilization rate of renewable energy at the same time; as a high-quality active / reactive power regulation power source on the power supply side, the energy storage power station realizes the load matching of electrical energy in terms of time and space, enhances the consumption capacity of renewable energy, reduces instantaneous power changes, reduces the impact on the grid, improves the problem of new energy power generation consumption, and is of great significance in terms of grid system standby, alleviating the power supply pressure during peak loads, and peak shaving and frequency modulation.

[0054] (2) Energy storage containers applied on the grid side mainly function in peak shaving, frequency modulation, and alleviating grid congestion peak shaving. They can achieve peak shaving and valley filling of the electricity load, that is, charging the energy storage battery during the off-peak electricity load period and releasing the stored electricity during the peak electricity load period, so as to achieve the balance between power production and consumption.

[0055] (3) Small energy storage cabinets applied to the power consumption side mainly function in self-use of electricity generation, arbitrage of peak-valley price differences, capacity charge management, and improvement of power supply reliability. According to different application scenarios, energy storage on the power consumption side can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in combination with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price difference arbitrage and capacity charge management. In the electricity market implementing peak-valley electricity prices, by charging the energy storage system at low electricity prices and discharging the energy storage system at high electricity prices, peak-valley electricity price difference arbitrage is achieved, reducing the electricity consumption cost. In addition, industrial enterprises applicable to two-part electricity prices can use the energy storage system to store energy during low electricity consumption valleys and discharge during peak load periods, thereby reducing the peak power and the declared maximum demand, achieving the purpose of reducing capacity electricity charges. Energy storage configured for household photovoltaics can improve the level of self-use of electricity generation. Due to high electricity prices and poor power supply stability, it drives the demand for household photovoltaic installations. Considering that photovoltaics generate electricity during the day while users generally have higher loads at night, by configuring energy storage, photovoltaic power can be better utilized, improving the level of self-use and reducing the electricity consumption cost at the same time. In addition, energy storage needs to be configured in fields such as communication base stations and data centers for backup power supplies.

[0056] Please refer to Figure 1 , Figure 1 is a schematic structural diagram of an energy storage system according to an embodiment of the present disclosure, and the embodiment of the present disclosure Figure 1 is described by taking the scenario of shared energy storage on the power generation / distribution side as an example. The energy storage system 100 of the present disclosure is not limited to its energy storage scenario on the power generation / distribution side.

[0057] The present disclosure provides an energy storage system, which includes: an energy storage device 110, a high-voltage cable 120, a first power conversion device 130, and a second power conversion device 140. In the case of power generation, the first power conversion device 130 and the second power conversion device 140 are used to convert other forms of energy into electrical energy, connect to the high-voltage cable 120 and supply it for use on the power distribution side of the power grid. When the power consumption load is low and the first conversion device 130 and the second power conversion device 140 generate excessive electricity, the excess electricity is stored in the energy storage device 110, reducing the curtailment rate of wind and light and improving the problem of new energy power generation accommodation; when the power consumption load is high, the power grid issues an instruction, and the electricity stored in the energy storage device 110 is transmitted in a grid-connected mode in cooperation with the high-voltage cable 120 to supply electrical energy for use on the power consumption side, providing various services such as peak regulation, frequency modulation, and standby for the operation of the power grid, giving full play to the role of the power grid in peak regulation, promoting peak shaving and valley filling of the power grid, and alleviating the power supply pressure of the power grid.

[0058] Optionally, the first power conversion device 130 and the second power conversion device 140 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0059] The number of energy storage devices 110 can be multiple. The multiple energy storage devices 110 are connected in series or in parallel with each other, and the multiple energy storage devices 110 are supported and electrically connected by a separator (not shown in the figure). In this embodiment, "multiple" means two or more. An energy storage box may also be provided outside the energy storage device 110 for housing the energy storage device 110.

[0060] Optionally, the energy storage device 110 may include, but is not limited to, a single cell, a battery equalization system, a battery pack, a battery system, etc. The actual application form of the energy storage device 110 provided in the embodiments of the present disclosure may be, but is not limited to, the listed products, and may also be other application forms. The embodiments of the present disclosure do not strictly limit the application form of the energy storage device 110. The embodiments of the present disclosure are only described by taking the energy storage device 110 as a single cell as an example. When the energy storage device 110 is a single cell, the energy storage device 110 may be at least one of a cylindrical battery, a square battery, etc.

[0061] With the continuous development of energy storage systems, the number of large-sized and high-capacity products has increased, and the consistency problem of battery systems has become more and more serious. For the situation where the voltage difference or temperature difference of the battery cells is too large, it can be optimized through the equalization technology of the Battery Management System (BMS).

[0062] The equalization technology includes active equalization and passive equalization. Among them, passive equalization realizes equalization by dissipating the energy of the battery cells with high voltage through resistance heating, and active equalization realizes equalization by transferring energy from high-energy to low-energy. The above two equalization methods are both equalized by the slave BMS through physical wire harnesses.

[0063] For passive equalization, the equalization current is small, usually about 100 mA. For large-sized and high-capacity products, passive equalization requires a long time to show an equalization effect, which affects the use of the energy storage system. For the energy storage system, passive equalization is slightly insufficient; for active equalization, the equalization current is large, usually 2 A - 5 A, but active equalization has strict requirements on wire harnesses, safety, heating, structure, etc. Usually, one equalization module corresponds to one battery cell, and the equalization efficiency is not high.

[0064] Both the above passive equalization and active equalization use the BMS to perform equalization through physical wire harnesses. On the one hand, the equalization technology is limited by the wire diameter of the wire harness. When the wire diameter of the wire harness is too small, long-time and large-current equalization cannot be achieved; on the other hand, the equalization technology is limited by the device problems of the BMS. During the equalization process, the BMS has a risk of heating, and the control strategy of the BMS is complex. In addition to the equalization strategy, the control strategy also includes other strategies such as the performance parameter acquisition strategy.

[0065] To solve at least some of the above technical problems, the battery equalization system of the present disclosure includes a battery pack, a battery management system, an equalization unit, and a controller; the battery pack includes a box body, a cover body, and a plurality of battery cells in the box body, and one battery cell corresponds to one equalization unit; the battery management system is connected to the plurality of battery cells, and the battery management system communicates with the controller for determining the battery cells to be equalized and generating an equalization control instruction; each equalization unit includes a transmitter and a receiver, the transmitter and the receiver are oppositely arranged and magnetically inductively connected, the receiver is connected to a corresponding battery cell, the transmitter is arranged on the inner wall of the cover body opposite to a battery cell, and the transmitter is connected to an auxiliary device; the controller is arranged on the inner wall of the cover body, the input end of the controller is electrically connected to the battery management system, and the controller is electrically connected to the transmitter for controlling the transmitter to selectively connect to the auxiliary device according to the equalization control instruction generated by the battery management system, so as to control the battery cells to be equalized to output or input electric energy, and realize the equalization of a plurality of battery cells. On the one hand, the present disclosure can realize the wireless equalization function, reduce the wire harness connection, set the equalization current as required, and improve the equalization efficiency; on the other hand, the present disclosure can not change the original arrangement of the battery cells, without changing the layout of the battery management system of the product, has better compatibility, and releases the equalization function from the BMS, reducing the computing power of the BMS and the complexity of the equalization strategy, and improving the focus of the BMS. The specific description is as follows through the following embodiments:

[0066] Figure 2 FIG. 4 shows a schematic structural diagram of a battery equalization system 200 provided by an embodiment of the present disclosure. In combination with Figure 2 FIG. 4, the battery equalization system 200 in the embodiment of the present disclosure includes a battery pack, a battery management system, an equalization unit 250, and a controller 260. Among them, the battery pack includes a box body 210, a cover body 220, and a plurality of battery cells 230 in the box body 210, and one battery cell 230 corresponds to one equalization unit 250; the battery management system is connected to the plurality of battery cells 230, and the battery management system communicates with the controller 260 for determining the battery cells 230 to be equalized and generating an equalization control instruction; each equalization unit 250 includes a transmitter 252 and a receiver 251, the transmitter 252 and the receiver 251 are oppositely arranged and magnetically inductively connected, the receiver 251 is connected to a corresponding battery cell 230, the transmitter 252 is arranged on the inner wall of the cover body 220 opposite to a battery cell 230, and the transmitter 252 is connected to an auxiliary device; the controller 260 is arranged on the inner wall of the cover body 220, the input end of the controller 260 is electrically connected to the battery management system, and the controller 260 is electrically connected to the transmitter 252 for controlling the transmitter 252 to selectively connect to the auxiliary device according to the equalization control instruction generated by the battery management system, so as to control the battery cells 230 to be equalized to output or input electric energy, and realize the equalization of a plurality of battery cells 230.

[0067] The housing 210 can be a rectangular container or a circular container. The shape, depth, etc. of the housing 210 can be determined according to actual needs. In this disclosure, the rectangular housing 210 is taken as an example for illustration. The housing 210 has a cavity for accommodating a plurality of battery cells 230.

[0068] As Figure 2 shown, the cover 220 cooperates with the housing 210 to close the cavity of the housing 210, so as to protect the plurality of battery cells 230 in the housing 210 from dust or other environmental factors and keep the interior of the housing 210 clean and tidy.

[0069] The housing 210 and the cover 220 can be fixed by bolts or connected by other structural members. The structural members include but are not limited to latches, buckles, etc.

[0070] As Figures 3 - 4 shown, a plurality of battery cells 230 are connected in series, and the plurality of battery cells 230 can be arranged in an array in the housing 210. It should be noted that the number of battery cells 230 can be determined according to actual needs. As Figure 3 shown, the battery pack includes 8 battery cells 230. The 8 battery cells 230 are divided into two columns, and the 4 battery cells 230 in each column are arranged side by side in the housing 210. For the battery cells 230 in each column, the positive electrode posts 231 of the battery cells 230 in the odd rows and the negative electrode posts 231 of the battery cells 230 in the even rows are located on the same straight line; the negative electrode posts 231 of the battery cells 230 in the odd rows and the positive electrode posts 231 of the battery cells 230 in the even rows are located on the same straight line. For the adjacent columns of battery cells 230, the electrode polarities of two adjacent battery cells 230 in the same row are opposite.

[0071] For the current battery cell 230 in a column, the positive electrode post 231 of the current battery cell 230 is electrically connected to the negative electrode post 231 of the previous battery cell 230 through the bus bar 240, and the negative electrode post 231 of the current battery cell 230 is electrically connected to the positive electrode post 231 of the next battery cell 230 through the bus bar 240.

[0072] When the current battery cell 230 is the first battery cell 230, the positive electrode post 231 of the current battery cell 230 is connected to the high-voltage switch box. When the current battery cell 230 is the last battery cell 230 in the corresponding column, the negative electrode post 231 of the current battery cell 230 is electrically connected to the positive electrode post 231 of the first battery cell 230 in the adjacent column through the bus bar 240.

[0073] In one embodiment, one battery cell 230 corresponds to one balancing unit 250. Each balancing unit 250 includes a transmitter 252 and a receiver 251. The transmitter 252 and the receiver 251 are arranged opposite to each other and magnetically inductively connected. The receiver 251 is connected to a corresponding battery cell 230. The transmitter 252 is disposed on the inner wall of the cover 220 opposite to the battery cell 230, and the transmitter 252 is connected to an auxiliary device. The transmitter 252 and the receiver 251 charge or discharge the battery cell 230 to be balanced based on the principle of electromagnetic induction, and transmit energy through the magnetic field, so that there is no need to connect the auxiliary device and the battery cell 230 to be balanced through a physical wire, thereby realizing a convenient and efficient balancing function.

[0074] The connection between the receiver 251 and the battery cell 230 can be made by wire connection, that is, the positive electrode terminal 231 and the negative electrode terminal 231 of the battery cell 230 are respectively connected to the receiver 251 to form a balancing circuit; or other contact methods can be used to realize the connection between the receiver 251 and the electrode terminal 231 of the battery cell.

[0075] The relative arrangement of the transmitter 252 and the receiver 251 means that along the axis direction of the electrode terminal 231 of the battery cell, the transmitter 252 and the receiver 251 are stacked or correspondingly arranged. There is no need for a physical wire connection between the transmitter 252 and the receiver 251. The receiver 251 is relatively fixed to the battery cell 230, and the transmitter 252 is relatively fixed to the cover 220.

[0076] In the present disclosure, both the transmitter 252 and the receiver 251 are rectangular plate-like structures. A variety of functional circuits can be integrated in both the transmitter 252 and the receiver 251.

[0077] The battery management system can determine the battery cell 230 to be balanced according to the state of the battery cell 230 and generate a balancing control instruction. The balancing control instruction can include a battery cell charging control instruction and / or a battery cell discharging control instruction. The battery cell charging control instruction is used to charge the battery cell 230 to be balanced when the voltage of the battery cell 230 to be balanced is lower than that of other battery cells 230, and the battery cell discharging control instruction is used to discharge the battery cell 230 to be balanced when the voltage of the battery cell 230 to be balanced is higher than that of other battery cells 230.

[0078] The balancing control instruction can carry the box number where the battery cell 230 to be balanced is located, the identification of the battery cell 230 to be balanced, and the balancing type, etc. Among them, the box number can be the number of the battery pack housing 210, which is used to uniquely determine the battery pack. The identification of the battery cell 230 to be balanced is used to locate the position of the battery cell 230 to be balanced in the housing 210 to uniquely determine the battery cell 230. The balancing type can include charging, discharging, etc. The box number, the identification of the battery cell 230, and the balancing type can be represented in forms such as text, numbers, symbols, etc. The present disclosure does not make specific limitations on this.

[0079] The BMS can identify the state of the battery cells 230 and determine whether there are battery cells 230 that need to be balanced (referred to as the battery cells 230 to be balanced in this disclosure). The determination basis of the BMS can be based on the execution standard required by the battery cells 230. For example, if the voltage difference or temperature of multiple battery cells 230 is greater than or equal to a preset threshold, the battery cells 230 to be balanced among the multiple battery cells 230 are determined. After the BMS determines the battery cells 230 to be balanced, it can generate a balancing control instruction and send the balancing control instruction to the controller 260, so that the controller 260 controls the corresponding balancing unit 250 to balance the battery cells 230 to be balanced.

[0080] The controller 260 can be arranged on the inner wall of the cover 220. The controller 260 is electrically connected to the transmitter 252 and is used to control the transmitter 252 to selectively connect to the auxiliary device according to the balancing control instruction generated by the battery management system, so as to control the battery cells 230 to be balanced to output or input electric energy, and achieve the balance of multiple battery cells 230.

[0081] The auxiliary device can include a charging device and an electrical load. When the balancing control instruction is a battery cell discharge control instruction, the controller 260 controls the transmitter 252 to connect to the electrical load, and the battery cells 230 to be balanced output electric energy to the electrical load; when the balancing control instruction is a battery cell charging control instruction, the controller 260 controls the transmitter 252 to connect to the charging device, the charging device outputs electric energy to the battery cells 230 to be balanced, and the battery cells 230 to be balanced input electric energy, thereby achieving the balance of multiple battery cells 230.

[0082] The charging device can be a charging pile or other power sources used to charge the battery cells 230; the electrical load can be a heat dissipation element such as a resistor, or an electrical device in the battery pack, such as the BMS, the energy management system, etc. This disclosure does not make specific limitations.

[0083] In an embodiment of the present disclosure, the battery balancing system 200 includes a battery pack, a battery management system, a balancing unit 250, and a controller 260; the battery pack includes a box body 210, a cover body 220, and a plurality of battery cells 230 inside the box body 210, and one battery cell 230 corresponds to one balancing unit 250; the battery management system is connected to the plurality of battery cells 230, and the battery management system communicates with the controller 260 to determine the battery cells 230 to be balanced and generate a balancing control instruction; each balancing unit 250 includes a transmitter 252 and a receiver 251, the transmitter 252 and the receiver 251 are oppositely arranged and magnetically inductively connected, the receiver 251 is connected to a corresponding one of the battery cells 230, the transmitter 252 is arranged on the inner wall of the cover body 220 opposite to one battery cell 230, and the transmitter 252 is connected to an auxiliary device; the controller 260 is arranged on the inner wall of the cover body 220, and the controller 260 is electrically connected to the transmitter 252 to control the transmitter 252 to selectively connect to the auxiliary device according to the balancing control instruction generated by the battery management system, so as to control the battery cells 230 to be balanced to output or input electric energy, and realize the balance of the plurality of battery cells 230. On the one hand, the present disclosure can realize the wireless balancing function, reduce the connection of the wire harness 261, set the balancing current as required, and improve the balancing efficiency; on the other hand, the present disclosure can not change the original arrangement of the battery cells 230, without changing the layout of the battery management system of the product, has better compatibility, and releases the balancing function from the BMS, reducing the computing power of the BMS and the complexity of the balancing strategy, and improving the focus of the BMS.

[0084] In one embodiment, as Figure 4 and Figure 5 shown, the cover body 220 is provided with a wire column 221, the controller 260 is connected to the wire column 221 through a wire harness 261, and the wire column 221 is connected to a power source, thereby forming a power input and output loop.

[0085] The power pins of the controller 260 are respectively connected to the wire harness 261, and the other end of the wire harness 261 is connected to the wire column 221. The wire harness 261 and the wire column 221 can be fixedly connected by plugging or by welding. The present disclosure does not make specific limitations on this.

[0086] The controller 260 is arranged in the cover body 220 on the side far from the wire column 221, and the controller 260 is arranged close to the inner wall of the cover body 220. The controller 260 can be a microcontroller unit (MCU) for accurately selecting the transmitter 252 that needs to start balancing and controlling the magnitude of the balancing current. In the following text, the MCU refers to the controller 260.

[0087] The wire harness 261 can use a wire harness 261 with insulation and high temperature resistance.

[0088] The cover body 220 includes a cover plate. The edge of the cover plate is folded downward to form the side wall of the cover body 220. Two wire columns are provided on one of the side walls of the cover body 220. An avoidance hole for the wire column 221 to pass through is provided on the side wall of the box body 210 corresponding to the above-mentioned one side wall. Two lead cylinders are provided on this side wall of the box body 210. When the cover body 220 is closed on the box body 210, the wire column 221 passes through the corresponding avoidance hole and extends into the lead cylinder, and the wire column 221 is connected to the power supply through a wire.

[0089] It should be noted that the power supply can be an external power supply or a power supply formed by connecting multiple battery cells 230 in series.

[0090] In the embodiment of the present disclosure, the controller 260 is connected to the power supply through the wire harness 261 and the wire column 221 provided on the cover body 220. The connection method is simple, which improves the reliability of the battery equalization system 200.

[0091] Continue to refer to Figure 5 , a plurality of fixing members 222 for fixing the wire harness 261 are provided on the inner wall of the cover body 220, and the plurality of fixing members 222 are distributed along the outer contour of the plurality of transmitters 252. The wire harness 261 connected to the power supply pin of the controller 260 includes two bundles. The two wire harnesses 261 are separated along the outer contour of the plurality of transmitters 252, and the two wire harnesses 261 extend close to the inner wall of the cover body 220 to the wire column 221 respectively.

[0092] In Figure 5 , each wire harness 261 is fixed by 4 fixing members 222. The fixing members 222 can include at least one of a buckle, a hook, and a cable tie.

[0093] Exemplarily, the fixing member 222 is a buckle. The buckle is a plate body with elastic deformation. The buckle can be integrally formed with the cover body 220. One end of the buckle is fixed on the cover body 220, and the other end of the buckle is a free end. The wire harness 261 is placed between the buckle and the cover body 220 to achieve fixation. The free ends of the plurality of buckles are alternately arranged close to the inner side wall of the cover body 220, thereby improving the fixing effect of the wire harness 261.

[0094] Exemplarily, the fixing member 222 is a hook. The hook has a hook portion, and the end of the hook away from the hook portion is fixed on the cover body 220. The wire harness 261 is placed in the hook portion to achieve fixation.

[0095] In addition, the wire harness 261 can also be fixed by an alternating bonding method, and the present disclosure does not make specific limitations on this.

[0096] In the embodiment of the present disclosure, the wire harness 261 is fixed by the fixing member 222, so that the wiring of the wire harness 261 is more regular, and the reliability of the cover body 220 is improved.

[0097] In one embodiment, the transmitter 252 is adhesively fixed to the inner wall of the cover 220, and / or an installation groove for accommodating the transmitter 252 is provided on the inner wall of the cover 220.

[0098] The cover 220 can be made of a material with good heat conduction performance. For example, copper or silver can be plated on the inner surface of the cover 220 to ensure good heat dissipation of the transmitter 252 and improve the reliability of the transmitter 252.

[0099] For example, an installation groove can be provided on the inner wall of the cover 220, and the transmitter 252 is fixed by interference fit with the installation groove. Glue can also be filled in the installation groove, and the transmitter 252 is fixed to the cover 220 by gluing and grooving methods, so as to simply and conveniently fix the transmitter 252.

[0100] As Figure 6 shown, in one embodiment, the controller includes a filter circuit, the filter circuit is electrically connected to an auxiliary device, and the auxiliary device includes a charging device and an electrical load; a plurality of transmitters 252 are connected to a data bus, and the data bus is electrically connected to the filter circuit through a first loop conduction switch 262.

[0101] The data bus can be the wire harness 261 in the foregoing embodiment. A plurality of transmitters 252 are connected in parallel to the data bus.

[0102] The data bus is electrically connected to the filter circuit through the first loop conduction switch 262, and the filter circuit is connected to the power supply lines B+ and B-, so that the controller 260 selectively electrically connects the transmitter 252 to the charging device or the electrical load by controlling the first loop conduction switch 262.

[0103] The first loop conduction switch 262 can include, but is not limited to, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET or MOS tube), a bipolar transistor, etc.

[0104] As Figure 6 shown, the filter circuit can convert the power supply into the input required by the transmitter 252. Among them, the filter circuit can filter out the ripple in the rectified output voltage. The filter circuit can be composed of reactance elements. For example, the filter circuit can be a capacitor connected in parallel across the load resistor, or an inductor connected in series with the load, or a complex filter circuit composed of a capacitor and an inductor. The present disclosure does not make specific limitations on this.

[0105] The charging device can be a charging pile or other external power source. For example, Figure 6 the charging pile in [[ ]] is connected to the power supply lines B+ and B-, and a BMS and an electrical load are also connected to the power supply lines B+ and B-. Both ends of the MCU are connected to the power supply lines B+ and B-.

[0106] In the embodiments of the present disclosure, the transmitter 252 is selectively connected to the auxiliary device through the filter circuit and the first loop conduction switch 262, so as to achieve the equalization of the cells to be equalized and ensure the stability of the loop.

[0107] As Figure 7 shown, in one embodiment, each transmitter 252 includes a transmitting coil 2521 and a second loop conduction switch 2524 connected in series. The second loop conduction switch 2525 is connected to the data bus, and the control end of the second loop conduction switch 2524 is electrically connected to the controller 260, so as to select and turn on the corresponding transmitter 252 when equalizing the cells to be equalized through the second loop conduction switch 2525.

[0108] The second loop conduction switch 2525 may include, but is not limited to, MOS transistors, bipolar transistors, etc. The number of turns of the transmitting coil 2521 can be determined according to actual needs.

[0109] As Figure 7 shown, the transmitter 252 further includes a power amplifier connected in series with the transmitting coil. The power amplifier includes at least one of a resonant capacitor 2522, an inverter circuit 2523, or a chopper circuit 2524.

[0110] Exemplarily, the transmitting coil 2521 is connected to the resonant capacitor 2522, the resonant capacitor 2522 is connected to the inverter circuit 2523, the inverter circuit 2523 is connected to the chopper circuit 2524, and the chopper circuit 2524 is connected to the data bus through the second loop conduction switch 2525.

[0111] In one embodiment, the controller 260 further includes a PLC module and a PLC wake-up module. The PLC wake-up module is disposed in the transmitter 252. The PLC wake-up module is connected to the second loop conduction switch 2525, and the PLC module and the PLC wake-up module are connected.

[0112] The resonant capacitor 2522 is a circuit component, which can be composed of a capacitor and an inductor connected in parallel. When the capacitor discharges, the inductor starts to have a reverse recoil current, and the inductor charges. When the voltage of the inductor reaches the maximum, the capacitor discharges completely. Then the inductor starts to discharge, and the capacitor starts to charge, and so on, which is called resonance. During this process, the inductor continuously charges and discharges to generate electromagnetic waves.

[0113] The inverter circuit 2523 can convert direct current into alternating current. The inverter circuit 2523 can include a voltage source inverter circuit 2523 and a current source inverter circuit 2523, which can be determined according to actual situations. The present disclosure does not make specific limitations on the type selection of the inverter circuit 2523.

[0114] The chopper circuit 2524 can convert a DC voltage or current into a required DC voltage or current. By utilizing the characteristic that the switching transistor can quickly switch between the on and off states, the effective value and frequency of the input power supply signal can be adjusted to achieve control of the output signal. The chopper circuit 2524 can include, but is not limited to, a buck chopper circuit, a boost chopper circuit, a buck-boost chopper circuit, a Cuk chopper circuit, etc. The present disclosure does not make specific limitations on the selection of the chopper circuit 2524.

[0115] The PLC wake-up module can be used to wake up the PLC communication function of the transmitter 252. For example, the PLC can be woken up by an external control signal output by the controller 260, or can be triggered to wake up by the input signal status or other conditions.

[0116] In the embodiment of the present disclosure, after the transmitter 252 is woken up by the controller 260 and the power is turned on, the current generated passes through the transmitting coil 2521 to generate an alternating magnetic field. The power amplifier composed of the resonant capacitor 2522, the inverter circuit 2523, and the chopper circuit 2524 can provide the current intensity, thereby enhancing the intensity and coverage range of the magnetic field, and greatly enhancing the reliability of the battery equalization system 200.

[0117] As Figure 6 and Figure 7 shown, the number of turns of the transmitting coil 2521 is greater than or equal to 2; the transmitter 252 further includes a first selection switch 2526. The transmitting coil 2521 is electrically connected to the resonant capacitor 2522 through the first selection switch 2526, and the control end of the first selection switch 2526 is connected to the controller 260.

[0118] The first selection switch 2526 can be at least one two-way selection switch, or can be at least two single-way selection switches. The present disclosure does not make specific limitations. The number of the first selection switches 2526 can be the same as the number of turns of the transmitting coil 2521, so as to control the number of turns of the transmitting coil 2521 connected to the access loop.

[0119] The first selection switch 2526 can also be a multi-stage switch. The multi-stage switch includes a rotating or pressing operating device and multiple electrical contacts. Each electrical contact is connected to the transmitting coil 2521 with the corresponding number of turns. When there is no cell 230 that needs to be equalized, each electrical contact is in an open state; when there is a cell 230 that needs to be equalized, by rotating or pressing the operating device, the electrical contacts make contact or separation, thereby controlling the on and off of the circuit and enabling the transmitting coil 2521 with the corresponding number of turns to be connected to the circuit.

[0120] The number of turns of the transmitting coil 2521 can be determined according to actual requirements. The number of turns of the transmitting coil 2521 affects the balancing current. The magnitude of the balancing current can be set according to the space of the cover 220 and product requirements, and is related to the size, shape, material, and layout of the transmitting coil 2521, etc.

[0121] In the embodiment of the present disclosure, the controller 260 can control the connection of the first selection switch 2526 to the transmitting coil 2521 with the corresponding number of turns, so as to adjust the number of turns of the transmitting coil 2521 connected, and limit the magnetic field intensity emitted to the minimum allowable number of turns in the initial stage of balancing, so as to avoid excessive energy received by the receiver 251 at the beginning.

[0122] As Figure 4 shown, in one embodiment, the receiver 251 is disposed between the bus bar 240 of the battery cell 230 and the battery cell 230, or the receiver 251 is disposed between the integrated bus bar of the battery cell 230 and the battery cell 230. The receiver 251 is used to receive the magnetic field released by the transmitter 252, and the receiver 251 can be conveniently fixed so as to form a stable electrical contact between the receiver 251 and the battery cell 230.

[0123] In one embodiment, the receiver 251 is provided with a connection hole, the inner wall of the connection hole is provided with a conductive material, the connection hole is sleeved on the pole 231 of the battery cell 230, and the connection hole is in interference fit with the pole 231 of the battery cell 230.

[0124] The product type design of the transmitter 252 can be designed to be nested into the double connection holes of the pole 231 of the battery cell, and a hard contact method is adopted to realize the fixation of the transmitter 252.

[0125] The conductive material can be metal materials such as gold, silver, copper, and aluminum. While ensuring the fixation of the receiver 251, the electrical connection between the receiver 251 and the battery cell 230 can also be realized.

[0126] In one embodiment, the receiver 251 can be disposed between the integrated bus bar and the battery cell 230.

[0127] The integrated bus bar (Cells Contact System, CCS component), also known as the battery cover plate component, wire harness board integrated component, etc., the CCS component is mainly composed of a signal acquisition component (for example, flexible printed circuit board FPC, printed circuit board PCB, FFC, etc.), plastic structural parts, copper and aluminum bars, etc. The above components are connected into a whole through a hot pressing process to realize the series and parallel connection of battery cells and collect temperature and voltage, that is, a flexible printed circuit board FPC or printed circuit board PCB is used to replace the wire harness connection method.

[0128] In one embodiment, a heat insulation pad may also be provided between the receiver 251 and the battery cell 230. The heat insulation pad can keep a distance between the receiver 251 and the battery cell 230 without direct contact, avoiding heat conduction between the battery cell 230 and the receiver 251.

[0129] The heat insulation pad can be a ceramic heat insulation pad made of high-temperature ceramic materials, or a fiber heat insulation pad made of fiber materials such as glass fiber and silica gel. The present disclosure does not make specific limitations thereto.

[0130] As Figure 8 and Figure 9 shown, the receiver 251 includes a receiving coil 2511 and a third circuit conduction switch 2514 connected in series. The third circuit conduction switch 2514 is connected to the corresponding battery cell 230, and the control end of the third circuit conduction switch 2514 is electrically connected to the controller 260.

[0131] The receiver 251 further includes a resonance circuit 2512 and a rectification circuit 2513. The resonance circuit 2512 and the rectification circuit 1513 are connected in series with the receiving coil 2511. The receiving coil 2511 is connected to the resonance circuit 2512, the resonance circuit 2512 is connected to the rectification circuit 2513, and the rectification circuit 2513 is connected to the corresponding battery cell 230 through the third circuit conduction switch 2514.

[0132] When the receiving coil 2511 of the receiver 251 is placed within the magnetic field range of the transmitter 252, according to the principle of electromagnetic induction, an induced current will be generated in the receiving coil 2511.

[0133] The rectification circuit 2513 can convert the induced current from alternating current to direct current to charge the battery cell 230.

[0134] The third circuit conduction switch 2514 can be a switching element such as a MOS transistor or a bipolar transistor. The present disclosure does not make specific limitations thereto.

[0135] In one embodiment, the controller 260 communicates with the battery management system through Power Line Communication (PLC communication); the controller 260 communicates with the transmitter 252 through power line communication; the transmitter 252 communicates with the receiver 251 wirelessly.

[0136] The controller 260 communicates with the battery management system (such as a slave BMS or a master BMS) through PLC communication, which can be used to confirm the identification of the battery cell 230 to be balanced and feedback the performance data of the battery cell 230 to be balanced for verification. The performance data for interaction includes but is not limited to the voltage, temperature, etc. of the battery cell 230.

[0137] The controller 260 communicates with the transmitter 252 via PLC, and can be used to confirm information such as the voltage and temperature of the cells 230 to be balanced.

[0138] The transmitter 252 and the receiver 251 can perform wireless communication via Qi, PMA standard protocols, etc.

[0139] PLC communication is a communication technology that uses power lines as the transmission medium for data transmission. Data transmission is achieved by modulating current signals. PLC communication can adopt communication protocols such as Modbus protocol, Profibus protocol, Ethernet / IP protocol, DeviceNet protocol, EtherCAT protocol, serial communication protocol, and communication protocol parsing. In terms of data transmission, PLC communication can transmit data from one device to another device, and the above data can be control signals, transmitter data, alarm information, etc.

[0140] For example, a PLC wake-up module can be set in the transmitter 252. When the PLC wake-up module receives the information of the cells to be balanced sent by the controller 260, the PLC wake-up module is woken up.

[0141] In the embodiments of the present disclosure, communication is carried out among the controller 260, the battery management system, the transmitter 252, and the receiver 251. On the one hand, the performance data of the cells 230 is transmitted to determine the cells 230 to be balanced and generate an equalization control instruction; on the other hand, the equalization control instruction is transmitted to the corresponding transmitter 252 to achieve the equalization of the cells 230, thereby improving the stability and reliability of the battery equalization system 200.

[0142] In the present disclosure, the equalization circuit includes the transmitter 252 and the receiver 251. The number of the transmitter 252 and the receiver 251 is relatively large. By adding a controller 260, it can be used for overall coordination. Through PLC communication, the corresponding transmitter 252 can be confirmed to be activated, and multiple transmitters 252 can be activated simultaneously. The addresses of multiple transmitters 252 are identified through PLC.

[0143] The present disclosure does not require additional equalization wiring harness 261, eliminating the problem of equalization heating of the wiring harness 261. The magnitude of the equalization current can be designed according to the capabilities of the cells 230, enabling large-current rapid equalization. The equalization strategy is separated from the BMS control strategy, and the BMS conducts verification, reducing the development cycle, reducing the development workload, being able to optimize the consistency problem of the energy storage system, quickly completing equalization, reducing the system pressure difference, improving the equalization efficiency, enhancing the overall service life of the system, reducing the after-sales maintenance cost, and enhancing the user experience.

[0144] The following combines Figure 10 to illustrate the implementation process of the present disclosure. As Figure 10As shown, the processing procedure of the battery equalization system 200 includes:

[0145] The BMS identifies the status of the battery cells 230 and determines whether there are battery cells 230 to be equalized. When there are none, it re-identifies the status of the battery cells 230; when there are battery cells 230 to be equalized, it identifies the box number X where the battery cells 230 to be equalized are located and sends an activation signal to box X through the PLC.

[0146] When the MCU of box X receives the activation signal, the MCU of box X is activated and replies to the BMS.

[0147] When the MCU of box X does not receive the activation signal, it continuously transmits for a preset duration (e.g., 10 minutes) and determines whether it receives a response from the MCU of box X. If so, the MCU of box X is activated and replies to the BMS; if not, the BMS reports a fault in the MCU control board, stops sending, and waits for maintenance.

[0148] After the BMS receives the reply message that the MCU of box X is activated, it sends out the position and voltage and temperature information of the battery cells 230 to be equalized.

[0149] Box X receives the information of the battery cells 230 to be equalized, closes the output switch (such as the second loop conduction switch 2525 in the above embodiment), and transfers the information to the corresponding target transmitter 252 through PLC communication, such as transmitter 252A.

[0150] When the target transmitter 252 receives the activation instruction from the MCU, it closes the output switch of the transmitter 252 (the first selection switch 2526 in the above embodiment), activates the circuit, and the transmitting coil 2521 starts to work (through the first selection switch 2526, the number of turns of the transmitting coil 2521 connected can be adjusted to limit the emitted magnetic field strength to the minimum allowable number of turns to avoid the receiver 251 receiving too much energy at the beginning), and sends an activation instruction to the target receiver 251 to activate the corresponding target receiver 251 (such as receiver 251B).

[0151] When the target receiver 251 is activated, the target receiver 251 sends a confirmation signal to the target transmitter 252 and starts to detect information such as the voltage and temperature of the battery cells 230 to be equalized, and transfers the voltage and temperature and other information to the target transmitter 252.

[0152] When the target transmitter 252 does not receive the information transferred by the target receiver 251, the BMS reports a fault, stops sending, and waits for maintenance.

[0153] When the target transmitter 252 receives the information transmitted by the target receiver 251, the target transmitter 252 transmits the information to the MCU, and the MCU then transmits the information to the BMS. The BMS checks the information such as the voltage and temperature of the cells 230 to be balanced received.

[0154] When the information check fails, the BMS reports a fault, stops sending, and waits for maintenance.

[0155] When the information check passes, the BMS sends a start balancing instruction (the balancing control instruction in the above embodiment) to the MCU. The MCU transmits the start balancing instruction to the target transmitter 252. The target transmitter 252 sends the information to start balancing to the target receiver 251. The target transmitter 252 releases the first selection switch 2526 of the transmitting coil 2521 to the maximum, so that all coils of the transmitting coil 2521 are connected to the circuit.

[0156] The target receiver 251 receives the balancing requirement and closes the third circuit conduction switch 2514 to conduct the balancing circuit, ensuring that the receiving coil 2511 and the balancing circuit of the cell 230 are in a conducting state.

[0157] To maintain balancing, the MCU continuously sends the information of the cell 230 to the BMS, and the BMS continuously conducts checks. When the MCU detects that the temperature and voltage of the cell 230 do not meet the balancing conditions, the BMS generates and sends a balancing stop instruction.

[0158] The MCU receives the balancing stop instruction sent by the BMS and sends it to the target transmitter 252.

[0159] The target transmitter 252 receives the balancing stop instruction and sends it to the target receiver 251. The target transmitter 252 adjusts the first selection switch 2526 to limit the number of turns of the transmitting coil 2521 connected to the minimum.

[0160] The target receiver 251 receives the balancing stop instruction and disconnects the third circuit conduction switch 2514 to end the balancing.

[0161] The MCU receives the state of the switch disconnection feedback from the target transmitter 252 and disconnects the output switch of the MCU control board (the first circuit conduction switch 262 in the above embodiment) to end the balancing.

[0162] The BMS receives the switch state feedback from the MCU, pauses sending the activation signal of the PLC, and the MCU shuts down to end the balancing.

[0163] It should be noted that for the operation of determining whether there are cells 230 to be balanced, the cells 230 to be balanced can be determined according to the execution standards required by each manufacturer's cells 230, usually including the pressure difference or temperature of the cells 230.

[0164] For the operation of the above BMS to determine whether the verification passes, the verification information is determined by the manufacturer. For example, the verification information includes that the voltage error is less than or equal to 2 mV and the temperature error is less than or equal to 1 °C.

[0165] Based on this, the embodiments of the present disclosure also provide an energy storage system as described in the following embodiments. Since the principle of solving problems by the device embodiments is similar to that of the above battery equalization system 200 embodiments, the implementation of the energy storage system embodiments can refer to the implementation of the above battery equalization system 200 embodiments, and the repeated parts will not be described again.

[0166] The embodiments of the present disclosure also provide an energy storage system, which includes the battery equalization system 200 in the above embodiments. In this way, combined with the above battery equalization system 200, the safety of the energy storage system can be improved, and the applicable range of the energy storage system is wider.

[0167] In addition, the energy storage system may further include an air conditioning system, a fire protection system, a monitoring system, a central control cabinet, an inverter system, etc. The air conditioning system is arranged in the air conditioning compartment, and the air conditioning system can be used to cool the battery pack.

[0168] It should be noted that although several modules or units of devices for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of the two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0169] In addition, although the steps of the methods in the present disclosure are described in a specific order in the drawings, this does not require or imply that these steps must be executed in this specific order, or that all the steps shown must be executed to achieve the desired result. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution, etc.

[0170] Through the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described here can be implemented by software, or by a way of software combined with necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on the network, including several instructions to enable a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, etc.) to execute the methods according to the embodiments of the present disclosure.

[0171] Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include well-known knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the appended claims.

Claims

1. A battery balancing system, characterized in that: include: Battery packs, battery management systems, balancing units and controllers; Wherein, the battery pack comprises a box body, a cover body, and a plurality of battery cells in the box body, and one battery cell corresponds to one balancing unit; The battery management system is connected to the plurality of battery cells, and the battery management system communicates with the controller to determine the battery cells to be balanced and generate a balancing control instruction; Each of the balancing units comprises a transmitter and a receiver, the transmitter and the receiver are arranged opposite to each other and are connected by magnetic induction, the receiver is connected to a corresponding battery cell, the transmitter is arranged on the inner wall of the cover opposite to the battery cell, and the transmitter is connected to an auxiliary device; The controller is disposed on the inner wall of the cover, and is electrically connected to the transmitter, and is used to control the transmitter to selectively connect to the auxiliary device, so as to control the output power or input power of the battery cell to be balanced, so as to achieve balancing of multiple battery cells.

2. The battery equalization system according to claim 1, characterized in that: The cover body is provided with a wire post, the controller is connected to the wire post through a wire harness, and the wire post is connected to a power source.

3. The battery equalization system according to claim 1, characterized in that: The controller includes a filter circuit, the filter circuit is electrically connected to the auxiliary device, and the auxiliary device includes a charging device and an electrical load; The plurality of transmitters are connected to a data bus, and the data bus is electrically connected to the filter circuit via a first loop conduction switch.

4. The battery equalization system according to claim 3, characterized in that: Each of the transmitters includes a transmitting coil and a second loop conduction switch connected in series, the second loop conduction switch is connected to the data bus, and a control end of the second loop conduction switch is connected to the controller.

5. The battery equalization system according to claim 4, characterized in that: The transmitter further comprises a power amplifier connected in series with the transmitting coil, wherein the power amplifier comprises a resonant capacitor, an inverter circuit and a chopper circuit.

6. The battery equalization system according to claim 4, characterized in that: The controller also includes a power communication PLC module and a PLC wake-up module, and the PLC wake-up module is arranged in the transmitter; the PLC wake-up module is connected to the control end of the second loop conduction switch.

7. The battery equalization system according to claim 5, characterized in that: The transmitter also includes a first selection switch, and the number of turns of the transmitting coil is greater than or equal to 2; the transmitting coil is electrically connected to the resonant capacitor through the first selection switch, and the control end of the first selection switch is connected to the controller.

8. The battery equalization system according to claim 1, characterized in that: The receiver includes a receiving coil and a third loop conduction switch connected in series, the third loop conduction switch is connected to a corresponding battery cell, and a control end of the third loop conduction switch is electrically connected to the controller.

9. The battery equalization system according to claim 8, characterized in that: The receiver further includes a resonant circuit and a rectifier circuit, wherein the resonant circuit, the rectifier circuit and the receiving coil are connected in series.

10. The battery balancing system according to any one of claims 1 to 9, characterized in that: The controller communicates with the battery management system via power; The controller communicates with the transmitter via power; The transmitter communicates wirelessly with the receiver.

11. An energy storage system, characterized in that: The invention comprises a battery balancing system as claimed in any one of claims 1 to 10.

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