Equalization circuit and equalization system

Abstract

This application provides an equalization circuit and equalization system that can effectively reduce the equalization cost among multiple battery cells. The equalization circuit is connected to a sampling chip, which samples the battery parameters of the multiple battery cells. The equalization circuit includes: a boost circuit, whose first input terminal receives the voltage of a target battery cell from the multiple battery cells and boosts the voltage of the target battery cell to the target voltage; and a drive circuit, whose input terminal is connected to the output terminal of the boost circuit, and whose output terminal is connected to a target switch in a switch array. The drive circuit outputs a first drive signal based on the target voltage, which drives the target switch to turn on, thereby equalizing the battery cells to be equalized among the multiple battery cells. The target switch corresponds to the battery cell to be equalized.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to an equalization circuit and equalization system. Background Technology

[0002] With the large-scale grid connection of renewable energy sources (such as photovoltaics and wind power) and the popularization of electric vehicles, energy storage systems are playing an increasingly prominent role in grid peak shaving, frequency regulation, and stable operation of microgrids. Energy storage systems include battery devices, which are typically composed of multiple battery cells connected in series or parallel. Due to differences in manufacturing processes, temperature distribution, and aging, voltage inconsistencies can occur between battery cells, leading to a "weakest link" effect in the entire energy storage system. This means that when a battery cell's charge is too low or too high, the overall charging and discharging capacity of the system decreases. When the charge is too low, the system cannot release its remaining capacity; when the charge is too high, the system cannot charge more energy, resulting in a reduction in the overall usable capacity of the energy storage system.

[0003] Therefore, how to effectively control the consistency of the charge level among individual battery cells in an energy storage system is an urgent problem to be solved. Utility Model Content

[0004] This application provides an equalization circuit and equalization system that can effectively reduce the equalization cost among multiple battery cells.

[0005] In a first aspect, an equalization circuit is provided, connected to a sampling chip. The sampling chip is used to sample battery parameters of multiple battery cells. The equalization circuit includes: a boost circuit, the first input terminal of which is used to receive the voltage of a target battery cell among the multiple battery cells and boost the voltage of the target battery cell to a target voltage; and a drive circuit, the input terminal of which is connected to the output terminal of the boost circuit, and the output terminal of which is connected to a target switch in a switch array. The drive circuit is used to output a first drive signal based on the target voltage. The first drive signal is used to drive the target switch to conduct, so as to equalize the battery cells to be equalized among the multiple battery cells. The target switch corresponds to the battery cell to be equalized.

[0006] In this embodiment, a boost circuit for raising the voltage and a drive circuit for driving the target switch array are provided. The drive circuit drives the target switch to conduct based on the target voltage output by the boost circuit, so as to balance the battery cells to be balanced. In this way, no other chip, such as a floating driver chip, is needed to turn on the target switch corresponding to the battery cell to be balanced, which reduces the circuit complexity of balancing the battery cells to be balanced, simplifies the circuit architecture, and effectively reduces the balancing cost.

[0007] In some possible implementations, the second input terminal of the boost circuit is used to receive a second drive signal, and the boost circuit is used to output the target voltage based on the voltage of the target battery and the second drive signal; the boost circuit includes at least one boost circuit, the boost circuit includes a plurality of first diodes, a first capacitor and a second capacitor, the plurality of first diodes are connected in series, the first capacitor and the second capacitor are respectively connected to the first terminal of different first diodes among the plurality of first diodes, the other terminal of the first capacitor is connected to the second input terminal, and the other terminal of the second capacitor is grounded.

[0008] This technical solution configures the boost circuit to include at least one boost circuit, and the boost circuit includes multiple first diodes, a first capacitor and a second capacitor connected in series. The first capacitor and the second capacitor are respectively connected to the first terminals of different first diodes among the multiple first diodes. The other terminal of the first capacitor is connected to the second terminal of the boost circuit, and the other terminal of the second capacitor is grounded. In this way, the purpose of boosting voltage can be effectively achieved.

[0009] In some possible implementations, the cell to be balanced and the target cell are the same, wherein the second drive signal includes the voltage signal output by the sampling chip.

[0010] In this technical solution, the second driving signal includes the voltage signal inside the sampling chip. In this way, the voltage signal that already exists inside the sampling chip can be reused, eliminating the need to generate a second driving signal. This simplifies the implementation and further reduces the complexity of equalization.

[0011] In some possible implementations, the target battery cell is the battery cell with the highest voltage among the plurality of battery cells, wherein the second drive signal includes the voltage signal output by the sampling chip.

[0012] In this technical solution, the second driving signal includes the voltage signal output by the sampling chip. That is, the sampling chip and the equalization circuit are not integrated together. As a result, there is no need to customize the sampling chip, which improves the applicability of the sampling chip.

[0013] In some possible implementations, the first drive signal includes a current signal with a constant current.

[0014] In this technical solution, the first driving signal includes a constant current signal, that is, the target current output by the driving circuit is constant, so as to obtain a stable voltage drop, which can drive the target switch to conduct more stably.

[0015] In some possible implementations, the driving circuit includes multiple second diodes, a first resistor, a second resistor, a first transistor, and a second transistor connected in series. The first ends of the multiple second diodes and one end of the second resistors are connected to the output of the boost circuit. The other end of the second resistor is connected to the emitter of the first transistor. The collector of the first transistor is connected to the target switch. The base of the first transistor is connected to the second end of the second diode and one end of the first resistor. The other end of the first resistor is connected to the collector of the second transistor. The base of the second transistor is used to receive a third driving signal, and the collector of the second transistor is grounded. The driving circuit outputs the current signal based on the target voltage and the third driving signal. This effectively achieves the goal of outputting a constant current.

[0016] In some possible implementations, the driving circuit further includes a third resistor, one end of which is connected to the base of the second transistor, and the other end of which is grounded.

[0017] This technical solution, by setting a third resistor in the driving circuit, not only helps to stabilize the state of the second transistor, but also protects the second transistor.

[0018] In some possible implementations, the driving circuit further includes a fourth resistor, one end of which is connected to the base of the second transistor, and the other end of which is used to receive the third driving signal.

[0019] The fourth resistor can limit the current. Therefore, by setting a fourth resistor in the drive circuit, this technical solution can reduce the possibility of the third drive signal damaging the second transistor, so that the drive circuit can operate normally.

[0020] In some possible implementations, the cell to be balanced and the target cell are the same, wherein the third driving signal includes a voltage signal inside the sampling chip.

[0021] In this technical solution, the third driving signal includes the voltage signal inside the sampling chip. In this way, the voltage signal that already exists inside the sampling chip can be reused, and there is no need to generate an additional third driving signal, which simplifies the implementation and further reduces the complexity of equalization.

[0022] In some possible implementations, the target battery cell is the battery cell with the highest voltage among the plurality of battery cells; wherein, the third driving signal includes the signal output from the first equalization port, which is the equalization port corresponding to the battery cell to be equalized among the plurality of equalization ports of the sampling chip. That is, the sampling chip and the equalization circuit are not integrated together, thus eliminating the need for customization of the equalization chip and improving its applicability.

[0023] In some possible implementations, the sampling chip includes multiple equalization ports. During the equalization process of the battery cell to be equalized, the first driving signal is used to turn on the first equalization port and the second equalization port among the multiple equalization ports. The target switch includes a first target sub-switch and a second target sub-switch. The first equalization port is connected to the first target sub-switch, the second equalization port is connected to the second target sub-switch, the first target sub-switch is connected to the battery cell to be equalized, and the second target sub-switch is connected to a battery cell adjacent to the battery cell to be equalized.

[0024] In this technical solution, only two of the multiple equalization ports of the sampling chip are turned on at any given time, meaning only two channels are turned on simultaneously. This reduces the possibility of a short circuit in the entire equalization system.

[0025] In some possible implementations, when the voltage of the battery cell to be balanced is greater than a first voltage threshold, the battery cell to be balanced outputs energy to the energy pool; when the voltage of the battery cell to be balanced is less than a second voltage threshold, the energy pool outputs energy to the battery cell to be balanced.

[0026] This technical solution involves the following steps: When the voltage of the individual battery cell to be balanced is greater than a first voltage threshold, the individual battery cell outputs energy to the energy pool. This reduces the voltage of the individual battery cell, allowing the voltages of multiple battery cells to reach a balanced state more quickly. When the voltage of the individual battery cell to be balanced is less than a second voltage threshold, the energy pool outputs energy to the individual battery cell. This increases the voltage of the individual battery cell, allowing the voltages of multiple battery cells to reach a balanced state more quickly, thereby improving the consistency among the multiple battery cells.

[0027] Secondly, a balancing method is provided, applied to a balancing circuit, wherein the balancing circuit is connected to a sampling chip, and the sampling chip is used to sample the battery parameters of multiple battery cells. The method includes: acquiring the voltage of a target battery cell among the multiple battery cells and raising the voltage of the target battery cell to a target voltage; and driving a target switch in a switch array to conduct based on a first driving signal to balance the battery cells to be balanced among the multiple battery cells, wherein the target switch corresponds to the battery cell to be balanced.

[0028] In some possible implementations, the method further includes: receiving a second driving signal; raising the voltage of a target battery cell among the plurality of battery cells to a target voltage includes: outputting the target voltage based on the voltage of the target battery and the second driving signal.

[0029] In some possible implementations, the cell to be balanced and the target cell are the same; wherein the second driving signal includes the voltage signal inside the sampling chip.

[0030] In some possible implementations, the target battery cell is the battery cell with the highest voltage among the plurality of battery cells; wherein, the second driving signal includes the voltage signal output by the sampling chip.

[0031] In some possible implementations, the first drive signal includes a current signal with a constant current.

[0032] In some possible implementations, the method further includes: receiving a third driving signal; the step of outputting a first driving signal based on the target voltage includes: outputting a current signal with constant current based on the third driving signal and the target voltage.

[0033] In some possible implementations, the equalization circuit is located inside the sampling chip, and the battery cell to be equalized is the same as the target battery cell; wherein, the third driving signal includes a voltage signal inside the sampling chip.

[0034] In some possible implementations, the equalization circuit is located outside the sampling chip, and the target battery cell is the battery cell with the highest voltage among the plurality of battery cells; wherein, the third driving signal includes the signal output by the first equalization port, and the first equalization port is the equalization port corresponding to the battery cell to be equalized among the plurality of equalization ports of the sampling chip.

[0035] In some possible implementations, the sampling chip includes multiple equalization ports, and the method further includes: during the equalization process of the battery cell to be equalized, activating a first equalization port and a second equalization port among the multiple equalization ports based on the first driving signal; wherein, the target switch includes a first target sub-switch and a second target sub-switch, the first equalization port is connected to the first target sub-switch, the second equalization port is connected to the second target sub-switch, the first target sub-switch is connected to the battery cell to be equalized, and the second target sub-switch is connected to a battery cell adjacent to the battery cell to be equalized.

[0036] In some possible implementations, the method further includes: controlling the battery cell to output energy to the energy pool when the voltage of the battery cell to be balanced is greater than a first voltage threshold; and controlling the energy pool to output energy to the battery cell to be balanced when the voltage of the battery cell to be balanced is less than a second voltage threshold.

[0037] Thirdly, an equalization system is provided, comprising: a plurality of battery cells; a switch array connected to the plurality of battery cells; a sampling chip for sampling the voltage of the plurality of battery cells; and an equalization circuit as described in the first aspect or its various implementations, wherein the equalization circuit is connected to the sampling chip, and the equalization system controls the equalization circuit through the sampling chip to equalize the battery cells to be equalized among the plurality of battery cells.

[0038] In some possible implementations, in a subset of the switches in the switch array, one switch corresponds to two battery cells out of the plurality of battery cells. Attached Figure Description

[0039] Figure 1 A schematic diagram of an equalization system according to an embodiment of this application is shown.

[0040] Figure 2 A schematic diagram of an equalization circuit according to an embodiment of this application is shown.

[0041] Figure 3 A schematic diagram of a boost circuit according to an embodiment of this application is shown.

[0042] Figure 4 A schematic diagram of another boost circuit according to an embodiment of this application is shown.

[0043] Figure 5 A schematic diagram of a driving circuit according to an embodiment of this application is shown.

[0044] Figure 6 A schematic diagram of another driving circuit according to an embodiment of this application is shown.

[0045] Figure 7 A schematic flowchart of an equilibration method according to an embodiment of this application is shown. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0048] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0050] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0051] With the widespread application of new energy sources such as solar and wind power, energy storage technology has developed accordingly. An energy storage system is a device or system capable of storing energy and releasing it when needed. In the field of new energy, energy storage systems typically refer to devices that can store electrical energy and release it during peak electricity demand periods. Energy storage systems play multiple roles in the power system, including load balancing, frequency regulation, backup power, peak-valley pricing management, and improving grid stability. With the rapid development of renewable energy, the importance of energy storage systems is increasing daily.

[0052] Electrochemical energy storage, represented by lithium-ion batteries, is the most widely used energy storage technology. An electrochemical energy storage system consists of battery devices, a battery management system (BMS), an energy management system (EMS), a power conversion system (PCS), and auxiliary equipment.

[0053] In an energy storage system, the battery unit is the energy storage medium, responsible for storing and releasing electrical energy. The Battery Management System (BMS) monitors and manages the battery unit's status, including state of charge, voltage, temperature, and current, to ensure safe operation and prevent over-discharge, overheating, and short circuits, thereby extending battery life. The Energy Management System (EMS) is the control center, responsible for monitoring the entire system's operation and optimizing energy storage and release strategies to meet grid demands or user-defined goals. The Power Control System (PCS) primarily controls the conversion and flow of electrical energy within the system, converting direct current (DC) to alternating current (AC) to meet grid or load requirements. Simultaneously, the PCS can also convert AC to DC to charge the battery units.

[0054] Battery devices are typically composed of multiple battery cells connected in series or parallel. Due to differences in manufacturing processes, temperature distribution, and aging, voltage inconsistencies can occur between battery cells. This voltage inconsistency means that during charging, the cell with the highest voltage will reach its maximum charging limit first, while during discharging, the cell with the lowest voltage will reach its minimum discharging limit first. This reduces the usable capacity of the battery device, thus shortening its overall lifespan.

[0055] Balancing technology can solve this problem, and balancing technology can include passive balancing and active balancing. Passive balancing achieves balancing by dissipating excess energy, discharging the battery cell with higher voltage through a resistor, so that its voltage is basically the same as the voltage of the other battery cells. However, passive balancing usually has the following disadvantages: (1) energy waste and low balancing efficiency; (2) slow balancing speed, and limited balancing efficiency for large-capacity battery devices; (3) balancing can only be performed at the end of charging and cannot improve the overall usable capacity.

[0056] Active balancing can transfer electrical energy from high-energy battery cells to low-energy battery cells or other battery devices to equalize the energy differences between battery cells. Active balancing has high balancing efficiency, allowing battery cells to reach a balanced state more quickly. However, current active balancing circuits are relatively complex.

[0057] In view of this, this application provides an equalization circuit connected to a sampling chip, which samples the battery parameters of multiple battery cells. The equalization circuit includes a boost circuit and a drive circuit. The first input of the boost circuit receives the voltage of a target battery cell from among the multiple battery cells and boosts the voltage of the target battery cell to the target voltage. The input of the drive circuit is connected to the output of the boost circuit, and its output is connected to a target switch in a switch array. The drive circuit outputs a first drive signal based on the target voltage, which drives the switch array to conduct, thereby equalizing the battery cells to be equalized among the multiple battery cells. The target switch corresponds to the battery cell to be equalized. This technical solution, by setting a boost circuit for boosting the voltage and a drive circuit for driving the target switch array, and by driving the target switch to conduct based on the target voltage output by the boost circuit, equalizes the battery cells to be equalized. Thus, without the need for other chips, such as a floating driver chip, the target switch corresponding to the battery cell to be equalized can be turned on, reducing the circuit complexity of equalizing the battery cells, simplifying the circuit architecture, and effectively reducing the equalization cost.

[0058] The balancing circuit in this application embodiment can be located on the cell supervisory circuit (CSC), which can be located within the battery device. The battery device mentioned in this application embodiment refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery device mentioned in this application may include a battery module or a battery pack, etc.

[0059] Figure 1A schematic diagram of an equalization system applicable to an embodiment of this application is shown. The equalization circuit of this embodiment can be located inside the analog front end (AFE) chip or outside the AFE chip. S0, S1, S2…S18 are the equalization ports of the AFE, and C0, C1, C2…C18 are the sampling ports of the AFE. The floating driver is used to drive the switching on and off of Q39, Q40, Q41, and Q42 under the control of the AFE. When a battery cell is discharging, the flyback controller 1 controls Q44 to be on, so that the battery cell releases electricity to the energy pool; when a battery cell is charging, the flyback controller 2 controls Q43 to be on, so that the battery cell receives electricity from the energy pool.

[0060] Assuming the voltage of battery cell 18 is lower than the preset voltage range, the equalization circuit drives Q1, Q2, Q3 and Q4 in the switch array to conduct. The conduction of Q1 and Q2 connects the positive terminal of battery cell 18 to Q39, and the conduction of Q3 and Q4 connects the negative terminal of battery cell 18 to Q42. The floating driver drives Q39 and Q42 to conduct, and the flyback controller 2 controls Q43 to turn on, so the energy pool can transfer energy to battery cell 18.

[0061] Assuming the voltage of battery cell 17 is higher than the preset voltage range, the equalization circuit drives Q3, Q4, Q5 and Q6 in the switch array to conduct. The conduction of Q3 and Q4 connects the positive terminal of battery cell 17 to Q40, and the conduction of Q5 and Q6 connects the negative terminal of battery cell 17 to Q41. The floating driver drives Q40 and Q41 to conduct, and the flyback controller 1 controls Q44 to turn on, so the energy pool can transfer energy to battery cell 18.

[0062] Figure 2 A schematic diagram of an equalization circuit according to an embodiment of this application is shown. The equalization circuit is connected to a sampling chip, which is used to sample battery parameters of multiple individual battery cells. Figure 2 As shown, the equalization circuit includes a boost circuit and a drive circuit. The first input terminal of the boost circuit receives the voltage of a target battery cell from a plurality of battery cells and boosts the voltage of the target battery cell to the target voltage. The input terminal of the drive circuit is connected to the output terminal of the boost circuit, and its output terminal is connected to a target switch in a switch array. The drive circuit outputs a first drive signal based on the target voltage. The first drive signal drives the target switch to conduct, thereby equalizing the battery cells to be equalized from the plurality of battery cells. The target switch corresponds to the battery cell to be equalized.

[0063] In this embodiment, a boost circuit for raising the voltage and a drive circuit for driving the target switch array are provided. The drive circuit drives the target switch to conduct based on the target voltage output by the boost circuit, so as to balance the battery cells to be balanced. In this way, the target switch corresponding to the battery cell to be balanced can be turned on without other chips, such as a floating driver chip. This reduces the circuit complexity of balancing the battery cells to be balanced, simplifies the circuit architecture, and effectively reduces the balancing cost.

[0064] Additionally, if the equalization circuit is applied to Figure 1 In the equilibrium system shown, such as Figure 1 As shown, the voltage at the source (S) terminal of a metal-oxide-semiconductor field-effect transistor (MOSFET) is the same as the voltage of the connected battery cell. To drive the target switch to conduct, current needs to flow through the MOSFET, causing a voltage drop across the resistor placed between the two MOSFETs. To achieve this, the driving voltage must be greater than the voltage of the battery cell. Therefore, by setting up a boost circuit, the voltage can be increased, thereby achieving the purpose of driving the target switch.

[0065] The sampling chip can be, for example, an AFE chip. Alternatively, it can be any other chip, such as one that combines sampling and equalization functions. Battery parameters can include, but are not limited to, voltage, current, and temperature.

[0066] Optionally, one equalization circuit corresponds to one battery cell. If there are multiple battery cells, multiple equalization circuits can be connected to one sampling chip, or they can be connected to multiple sampling chips.

[0067] A boost circuit can raise the voltage of a target battery cell to any voltage. For example, the difference between the target voltage and the voltage of the target battery cell can be 10V. This 10V difference between the target voltage and the voltage of the target battery cell can improve the on and off states of the target switch.

[0068] The first input terminal of the boost circuit can be connected to the target battery cell to receive its voltage. Alternatively, the first input terminal of the boost circuit can be connected to a sampling chip, which outputs the sampled voltage of the target battery cell to the first input terminal of the boost circuit.

[0069] The target switch corresponding to the battery cell to be balanced can be understood as follows: For example, referring again... Figure 1If the battery cell to be balanced is battery cell 18, then the target switches are Q1, Q2, Q3 and Q4; if the battery cell to be balanced is battery cell 17, then the target switches are Q3, Q4, Q5 and Q6.

[0070] The battery cell to be balanced can be either a battery cell with a voltage greater than a first voltage threshold or a battery cell with a voltage less than a second voltage threshold. The first voltage threshold is greater than the second voltage threshold.

[0071] The following explanation uses a battery cell whose voltage is below a second voltage threshold as an example. For instance, if the battery device's resting time exceeds a predetermined minimum time, the battery cells with a voltage below the minimum state of charge (SOC) threshold can be identified as the battery cells to be balanced based on their voltage and open circuit voltage (OCV) curves. Alternatively, if the battery device's resting time exceeds the predetermined minimum time, the voltage of each battery cell can be compared, and the battery cells with a voltage below the minimum threshold can be identified as the battery cells to be balanced. Furthermore, at the end of the charging process, the voltage of each battery cell can be compared, and the battery cells with a voltage below the minimum threshold can be identified as the battery cells to be balanced.

[0072] The first and second voltage thresholds can be fixed values, meaning that the first voltage threshold and the second voltage threshold are the same under any environment and any battery cell conditions. Alternatively, the first and second voltage thresholds can also be variable values, for example, determined according to specific circumstances, such as the environment in which the battery cell is located.

[0073] When the voltage of the battery cell to be balanced is greater than the first voltage threshold, the battery cell to be balanced can output energy; when the voltage of the battery cell to be balanced is less than the second voltage threshold, the battery cell to be balanced can receive energy.

[0074] As an example, when the voltage of the battery cell to be balanced is greater than the first voltage threshold, the battery cell to be balanced can output energy to the energy pool; when the voltage of the battery cell to be balanced is less than the second voltage threshold, the energy pool can output energy to the battery cell to be balanced.

[0075] This technical solution involves the following steps: When the voltage of the individual battery cell to be balanced is greater than a first voltage threshold, the individual battery cell outputs energy to the energy pool. This reduces the voltage of the individual battery cell, allowing the voltages of multiple battery cells to reach a balanced state more quickly. When the voltage of the individual battery cell to be balanced is less than a second voltage threshold, the energy pool outputs energy to the individual battery cell. This increases the voltage of the individual battery cell, allowing the voltages of multiple battery cells to reach a balanced state more quickly, thereby improving the consistency among the multiple battery cells.

[0076] Optionally, the energy pool may include, but is not limited to, a voltage source, a battery module, or a battery pack. The voltage source can be a voltage source within the energy storage system, or it can be a voltage source located outside the energy storage system. For example, the voltage source can be a 24V voltage source, or it can be a 12V, 3V, or other voltage source.

[0077] An energy pool can be, for example, a Figure 1 The energy pool in the middle. In the application of equalization batteries... Figure 1 In the balancing system shown, when the battery cell to be balanced is outputting energy to the energy pool (i.e., the battery is discharging), the flyback controller can control Q44 to periodically turn on and off to allow the battery cell to output energy to the energy pool. When the battery cell to be balanced is receiving energy from the energy pool (i.e., the battery is charging), the flyback controller can control Q43 to periodically turn on and off to allow the battery cell to output energy to the energy pool.

[0078] As another example, if the voltage of the battery cell to be balanced is greater than a first voltage threshold, the battery cell to be balanced can output energy to other battery cells, which can be battery cells with a voltage lower than a second voltage threshold. At this time, the switch corresponding to the other battery cell is in the on state.

[0079] Alternatively, if the voltage of the battery cell to be balanced is less than the second voltage threshold, the battery cell to be balanced can receive energy from other battery cells, which can be battery cells with a voltage greater than the first voltage threshold. In this case, the switch corresponding to the other battery cell is in the ON state.

[0080] As another example, when the voltage of the battery cell to be balanced is greater than the first voltage threshold, the battery cell to be balanced can simultaneously output energy to the energy pool and other battery cells, which can be battery cells with a voltage less than the second voltage threshold.

[0081] Alternatively, if the voltage of the battery cell to be balanced is less than the second voltage threshold, the battery cell to be balanced can simultaneously receive energy from the energy pool and other battery cells, which can be battery cells with a voltage greater than the first voltage threshold.

[0082] In one embodiment, the boost circuit and the driving circuit can be located inside the sampling chip, that is, the sampling chip includes a boost circuit and a driving circuit.

[0083] This technical solution places the boost circuit and drive circuit inside the sampling chip, which increases the integration of the sampling chip and the equalization circuit, thereby improving the equalization efficiency of the individual battery cells to be equalized.

[0084] When the boost circuit and drive circuit are located inside the sampling chip, the battery cell to be equalized and the target battery cell are the same.

[0085] In another embodiment, the boost circuit and the drive circuit can be located outside the sampling chip. By placing the boost circuit and the drive circuit outside the sampling chip, no customization of the sampling chip is required, thus improving the applicability of the sampling chip.

[0086] At this point, the target battery cell can be the one with the highest voltage among multiple battery cells. Thus, regardless of which battery cell needs to be balanced, the drive circuit can activate the target switch corresponding to that battery cell.

[0087] Alternatively, the target battery cell can be determined based on the battery cell to be balanced. For example, among multiple battery cells, any battery cell with a voltage higher than the battery cell to be balanced can be used as the target battery cell.

[0088] In some embodiments, the boost circuit may further include a second input terminal for receiving a second drive signal, and the boost circuit is used to output a target voltage based on the voltage of the target battery and the second drive signal.

[0089] In one possible implementation, the boost circuit may include at least one boost circuit, which may include a plurality of first diodes, a first capacitor and a second capacitor. The plurality of first diodes are connected in series, and the first capacitor and the second capacitor are respectively connected to the first terminals of different first diodes among the plurality of first diodes. The other terminal of the first capacitor is connected to the second input terminal, and the other terminal of the second capacitor is grounded.

[0090] This technical solution configures the boost circuit to include at least one boost circuit, and the boost circuit includes multiple first diodes, a first capacitor and a second capacitor connected in series. The first capacitor and the second capacitor are respectively connected to the first terminals of different first diodes among the multiple first diodes. The other terminal of the first capacitor is connected to the second terminal of the boost circuit, and the other terminal of the second capacitor is grounded. In this way, the purpose of boosting voltage can be effectively achieved.

[0091] For example, such as Figure 3 and Figure 4 As shown, each lifting circuit can include two first diodes.

[0092] The number of boosting circuits can be determined based on parameters such as the voltage to be boosted and the second driving signal (e.g., driving frequency). Similarly, the capacitance values ​​of the first and second capacitors can also be determined based on parameters such as the voltage to be boosted and the second driving signal.

[0093] For example, the second drive signal includes a 5-volt (V) voltage signal. Assuming the voltage of the target battery cell is Vcell and the target voltage is (Vcell+15V), the number of lifting circuits can be 3.

[0094] The first diode can be any diode. For example, such as... Figure 3 and Figure 4 As shown, Z1, Z2, Z3, and Z4 are the first diodes. It can be seen that... Figure 3 and Figure 4 The first diode in the circuit is a breakdown diode.

[0095] The second driving signal can be, for example, a square wave signal, a sawtooth wave signal, a triangular wave signal, etc. For example, the second driving signal can include 0 volts (V) and any voltage signal other than 0V, such as 3V, 5V, 8V, 10V, 15V, etc.

[0096] In other embodiments, the boost circuit may not include a second capacitor, or the boost circuit may include a second capacitor with the other end of the second capacitor not grounded.

[0097] Optionally, the second driving signal may include a voltage signal existing within the sampling chip. This allows for the reuse of the voltage signal already present within the sampling chip, eliminating the need to generate a separate second driving signal, simplifying implementation, and further reducing the complexity of equalization.

[0098] For example, such as Figure 3 As shown, when the sampling chip is an AFE chip, since the AFE chip itself has a 5V voltage, the second drive signal can include a 5V voltage signal.

[0099] At this point, the equalization circuit can be set inside the sampling chip.

[0100] Optionally, the second drive signal may include the voltage signal output by the sampling chip.

[0101] For example, such as Figure 4 As shown, the sampling chip can output a second drive signal to the boost circuit through the general purpose input / output (GPIO) interface.

[0102] At this point, the equalization circuit can be set outside the sampling chip.

[0103] by Figure 3 The working principle of the boost circuit will be explained using an example. Figure 3 The boost circuit includes two boosting circuits. The first diodes are Z1, Z2, Z3, and Z4; the first capacitors are C1 and C2; and the second capacitor is C3. The first boosting circuit includes Z1, Z4, C3, and C3 connected to Z4; the second boosting circuit includes Z2, Z3, C2, and C3 connected to Z3. Assume the voltage of the target battery cell is Vcelln, and the second drive signal includes 0V and 5V. When the second drive signal is 0V, the voltage at point A is Vcelln, and the voltage at point B is 0V. Switching the second drive signal to 5V, the voltage at point B becomes 5V. Since the voltage across C1 cannot change abruptly, the voltage at point A becomes Vcelln + 5V. C3 is the energy storage capacitor, so the voltage at point C becomes Vcelln + 5V, and the voltage at point D also becomes Vcelln + 5V. Switching the second drive signal back to 0V, since the voltage across C2 cannot change abruptly, the voltage at point D remains Vcelln + 5V. When the second drive signal is switched to 5V, the voltage at point E is 5V. Since the voltage across C2 cannot change abruptly, the voltage at point D is Vcelln+10V, and the voltage output by the boost circuit is Vcelln+10V.

[0104] In some embodiments, the first drive signal may include a voltage signal with a constant voltage.

[0105] Alternatively, the first drive signal may include a signal in which both voltage and current change.

[0106] Alternatively, the drive circuit can be used to output a constant target current based on the target voltage, which is used to drive the target switch to turn on. In other words, the first drive signal includes a constant target current.

[0107] This technical solution uses a target current with a constant output current from the drive circuit to obtain a stable voltage drop, which enables more stable drive of the target switch to conduct.

[0108] To achieve a constant output current based on the target voltage, in other words, to convert a voltage source into a current source, as an example, the driving circuit may include multiple second diodes, a first resistor, a second resistor, a first transistor, and a second transistor connected in series. One end of the multiple second diodes and the first end of the second resistors are connected to the output of the boost circuit. The other end of the second resistors is connected to the emitter of the first transistor. The collector of the first transistor is connected to the target switch. The base of the first transistor is connected to the second end of the second diodes and one end of the first resistor. The other end of the first resistor is connected to the collector of the second transistor. The base of the second transistor is used to receive a third driving signal, and the collector of the second transistor is grounded.

[0109] The driving circuit is used to output a current signal based on the target voltage and the third driving signal.

[0110] The above technical solution can effectively achieve the goal of outputting a constant current.

[0111] Figure 5 A possible schematic diagram of the drive circuit is shown. Figure 5 D1 and D2 in the diagram are the second diodes. It can be seen that there are two second diodes; however, the number could also be three, four, five, etc. Further discussion will follow. Figure 5 The working principle will be described in detail here.

[0112] Similar to the second driving signal, the third driving signal can be, for example, a square wave signal, a sawtooth wave signal, a triangular wave signal, etc.

[0113] Optionally, the third drive signal may include a first signal and a second signal. The first signal indicates that the battery cells corresponding to the drive circuit should not be balanced, and the second signal indicates that the battery cells corresponding to the drive circuit should be balanced. The first signal may, for example, include a 0V voltage signal. When the battery cells corresponding to the drive circuit are not balanced, the third drive signal outputs 0V.

[0114] Alternatively, the third drive signal may be output to the base of the second transistor only when equalization of the battery cells corresponding to the drive circuit is required. In other words, the third drive signal may consist only of the second signal and exclude the first signal.

[0115] The second signal can, for example, include any voltage signal greater than 0V, such as 3V, 5V, 10V, etc. Optionally, the third driving signal can include a voltage signal existing within the sampling chip. This allows for the reuse of the voltage signal already present within the sampling chip, eliminating the need to generate a separate third driving signal, simplifying implementation and further reducing the complexity of equalization. In this case, the second signal can, for example, be a 5V voltage signal from within the sampling chip. In this scenario, the equalization circuit can be located within the sampling chip.

[0116] Alternatively, the third driving signal may include the signal output from the first equalization port, which is the equalization port among the multiple equalization ports of the sampling chip that corresponds to the individual battery cell to be equalized. In other words, the base of the second transistor can be connected to the first equalization port.

[0117] The signal output from the first equalization port can be the voltage of the individual battery cell to be equalized.

[0118] In addition, the equalization port adjacent to the first equalization port can output a fourth driving signal, and the third driving signal and the fourth driving signal together drive the target switch to turn on.

[0119] At this point, the equalization circuit can be set outside the sampling chip.

[0120] The following is combined Figure 5 The working principle of the drive circuit is described using an example where the equalization circuit is located inside the sampling chip, and the third drive signal includes 0V and 5V voltage signals. Figure 5 In the diagram, D1 and D2 are the second diodes, R1 is the first resistor, R2 is the second resistor, QB is the first transistor, and QA is the second diode.

[0121] When the third drive signal is 0V, both QA and QB are off, and the target switch is not conducting. When the third drive signal is 5V, QA conducts, and the voltage drop from point N to point M is equal to the voltage drop of two diodes (D1 and D2). Similarly, the voltage drop from point N to R2 and QB is also equal to the voltage drop of two diodes, and QB conducts. Therefore, the voltage drop across R2 is equal to the voltage drop of one diode. Assuming the voltage drop of one diode is V1, the current through R2 is V1 / R2, and the target current output by the drive circuit is V1 / R2. Since V1 and R2 are both fixed values, the target current is also a fixed value.

[0122] Furthermore, the driving circuit may also include a third resistor, one end of which is connected to the base of the second transistor, and the other end of which is grounded. The third resistor could be, for example, a... Figure 6 R3 in the middle.

[0123] This technical solution, by setting a third resistor in the driving circuit, not only helps to stabilize the state of the second transistor, but also protects the second transistor.

[0124] The specific resistance value of the third resistor is not specifically limited in this application embodiment, as long as it can stabilize the state of the second transistor and protect the second transistor.

[0125] Furthermore, the driving circuit may also include a fourth resistor, one end of which is connected to the base of the second transistor, and the other end of which is used to receive a third driving signal.

[0126] The fourth resistor can limit the current. Therefore, by setting a fourth resistor in the drive circuit, this technical solution can reduce the possibility of the third drive signal damaging the second transistor, so that the drive circuit can operate normally.

[0127] like Figure 6 As shown, when the driving circuit includes a third resistor R3 and a fourth resistor R4, the base of the second transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is used to receive the third driving signal. One end of the third resistor is located between the base of the second transistor and the fourth resistor, and the other end is grounded together with the collector of the second transistor.

[0128] The sampling chip typically includes multiple equalization ports. In some embodiments, during the equalization process of the battery cells to be equalized, a first drive signal can activate the first and second equalization ports among the multiple equalization ports. The target switch includes a first target sub-switch and a second target sub-switch. The first equalization port is connected to the first target sub-switch, the second equalization port is connected to the second target sub-switch, the first target sub-switch is connected to the battery cell to be equalized, and the second target sub-switch is connected to a battery cell adjacent to the battery cell to be equalized.

[0129] In this technical solution, only two of the multiple equalization ports of the sampling chip are turned on at any given time, meaning only two channels are turned on simultaneously. This reduces the possibility of a short circuit in the entire equalization system.

[0130] In other words, in this embodiment of the application, the target switch is driven through two equalization ports.

[0131] The number of first target sub-switches can be one or more. Similarly, the number of second target sub-switches can also be one or more. For example, suppose the equalization circuit is applied to... Figure 1In the equalization system shown, if the battery cell to be equalized is battery cell 18, then the first target sub-switches are Q1 and Q2, and the second target sub-switches are Q3 and Q4. If the battery cell to be equalized is battery cell 17, then the first target sub-switches are Q3 and Q4, and the second target sub-switches are Q5 and Q6.

[0132] The technical solutions of the embodiments of this application are described below with reference to specific examples.

[0133] Assuming the sampling chip is an AFE chip, and if the equalization circuit is located inside the AFE chip, the battery cell to be equalized is battery cell 18, refer to... Figure 1 , Figure 3 and Figure 6 The AFE chip's equalization port S18 outputs a high level, i.e., Vcell18+10V, to drive Q1 and Q2 to conduct. Simultaneously, the equalization port S17 outputs a high level, i.e., Vcell17+10V, to drive Q3 and Q4 to conduct, and the AFE drives Q39 and Q42 to conduct. If battery cell 18 is discharging, the flyback controller controls Q44 to periodically turn on and off, thus allowing battery cell 18 to output energy to the energy pool. If battery cell 18 is charging, the flyback controller controls Q43 to periodically turn on and off, thus allowing battery cell 18 to receive energy from the energy pool.

[0134] If the equalization circuit is located outside the AFE chip, the battery cell to be equalized is cell 18, and the voltage drop of one diode is 0.7V. (Reference) Figure 1 , Figure 4 and Figure 6 The AFE chip's equalization port S18 outputs a high level, Vcell18, to drive QA18 and QB18 to conduct. Simultaneously, the equalization port S17 outputs a high level, Vcell17, to drive QA17 and QB17 to conduct. The voltage output by G17 and G18 is Vbat + 10V, and the current is 0.7V / R2. G18 drives Q1 and Q2 to conduct, and G17 drives Q3 and Q4 to conduct.

[0135] If battery cell 18 discharges, the flyback controller controls Q44 to periodically turn on and off, thereby allowing battery cell 18 to output energy to the energy pool. If battery cell 18 is charging, the flyback controller controls Q43 to periodically turn on and off, thereby allowing battery cell 18 to receive energy from the energy pool.

[0136] Wherein, QA18 and QB18 represent QA and QB in the drive circuit connected to battery cell 18, QA17 and QB17 represent QA and QB in the drive circuit connected to battery cell 17, G18 represents G in the drive circuit connected to battery cell 18, and G17 represents G in the drive circuit connected to battery cell 17. (The above is a combination of...) Figures 2-6 The equalization circuit of an embodiment of this application is described below, and will be combined with Figure 7 The present application describes method embodiments. It should be understood that the method embodiments correspond to the apparatus embodiments, and similar descriptions can be found in the apparatus embodiments.

[0137] Figure 7 A schematic flowchart of an equalization method according to an embodiment of this application is shown. This equalization method is applied to an equalization circuit, which is connected to a sampling chip. The sampling chip is used to sample the battery parameters of multiple individual battery cells.

[0138] like Figure 7 As shown, the balancing method 700 may include the following steps.

[0139] S710: Obtain the voltage of the target battery cell among multiple battery cells, and raise the voltage of the target battery cell to the target voltage.

[0140] S720: Outputs the first drive signal based on the target voltage.

[0141] S730: Based on the first driving signal, the target switch in the switch array is driven to turn on in order to balance the battery cells to be balanced among multiple battery cells. The target switch corresponds to the battery cell to be balanced.

[0142] Optionally, in some embodiments, method 700 further includes: receiving a second driving signal; S710 may specifically include: outputting a target voltage based on the voltage of the target battery and the second driving signal.

[0143] Optionally, in some embodiments, the battery cell to be equalized and the target battery cell are the same; wherein, the second driving signal includes a voltage signal inside the sampling chip.

[0144] Optionally, in some embodiments, the target battery cell is the battery cell with the highest voltage among multiple battery cells; wherein, the second driving signal includes the voltage signal output by the sampling chip.

[0145] Optionally, in some embodiments, the first drive signal includes a current signal with a constant current.

[0146] Optionally, in some embodiments, method 700 further includes: receiving a third driving signal; S720 may specifically include: outputting a current signal with constant current based on the third driving signal and the target voltage.

[0147] Optionally, in some embodiments, the equalization circuit is located inside the sampling chip, and the battery cell to be equalized and the target battery cell are the same; wherein, the third driving signal includes the voltage signal inside the sampling chip.

[0148] Optionally, in some embodiments, the equalization circuit is located outside the sampling chip, and the target battery cell is the battery cell with the highest voltage among multiple battery cells; wherein, the third driving signal includes the signal output by the first equalization port, and the first equalization port is the equalization port corresponding to the battery cell to be equalized among the multiple equalization ports of the sampling chip.

[0149] Optionally, in some embodiments, the sampling chip includes multiple equalization ports, and the method 700 further includes: during the equalization process of the battery cell to be equalized, activating the first equalization port and the second equalization port among the multiple equalization ports based on the first driving signal; wherein, the target switch includes a first target sub-switch and a second target sub-switch, the first equalization port is connected to the first target sub-switch, the second equalization port is connected to the second target sub-switch, the first target sub-switch is connected to the battery cell to be equalized, and the second target sub-switch is connected to the battery cell adjacent to the battery cell to be equalized.

[0150] Optionally, in some embodiments, method 700 further includes: controlling the battery cell to output energy to the energy pool when the voltage of the battery cell to be balanced is greater than a first voltage threshold; and controlling the energy pool to output energy to the battery cell to be balanced when the voltage of the battery cell to be balanced is less than a second voltage threshold.

[0151] It should be understood that Figure 7 The method 700 shown can be performed by the equalization circuit in the foregoing embodiments. It should be understood that... Figure 7 The steps or operations described are merely examples; other operations or procedures may also be performed in the embodiments of this application. Figure 7 Variations of various operations.

[0152] This application also provides an equalization system. The equalization system may include multiple battery cells, a switch array, a sampling chip, and an equalization circuit. The switch array is connected to the multiple battery cells, the sampling chip samples the battery parameters of the multiple battery cells, and the equalization circuit is connected to the sampling chip. The equalization system controls the equalization circuit through the sampling chip to equalize the battery cells to be equalized among the multiple battery cells.

[0153] Optionally, the equalization circuit can be Figure 2 The equalization circuit shown can have a boost circuit that can be used to equalize voltages. Figure 3 and Figure 4 The boost circuit shown can have the following driving circuit in the equalization circuit: Figure 5and Figure 6 The driving circuit shown.

[0154] This application also provides a computer-readable storage medium for storing a computer program for performing the methods described in the various embodiments of this application.

[0155] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0156] This application also provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described equalization method.

[0157] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An equalization circuit, characterized in that, The equalization circuit is connected to a sampling chip, which is used to sample the battery parameters of multiple battery cells. A boost circuit, wherein the first input terminal of the boost circuit is used to receive the voltage of the target battery cell among the plurality of battery cells and boost the voltage of the target battery cell to the target voltage; A driving circuit is provided, wherein the input terminal of the driving circuit is connected to the output terminal of the boost circuit, and the output terminal of the driving circuit is connected to the target switch in the switch array. The driving circuit is used to output a first driving signal based on the target voltage. The first driving signal is used to drive the target switch to turn on, so as to balance the battery cells to be balanced among the plurality of battery cells. The target switch corresponds to the battery cell to be balanced.

2. The equalization circuit according to claim 1, characterized in that, The second input terminal of the boost circuit is used to receive the second drive signal, and the boost circuit is used to output the target voltage based on the voltage of the target battery and the second drive signal; The boost circuit includes at least one boost circuit, which includes a plurality of first diodes, a first capacitor, and a second capacitor. The plurality of first diodes are connected in series. The first capacitor and the second capacitor are respectively connected to the first terminals of different first diodes among the plurality of first diodes. The other terminal of the first capacitor is connected to the second input terminal, and the other terminal of the second capacitor is grounded.

3. The equalization circuit according to claim 2, characterized in that, The battery cell to be balanced is the same as the target battery cell, wherein the second driving signal includes the voltage signal inside the sampling chip.

4. The equalization circuit according to claim 2, characterized in that, The target battery cell is the battery cell with the highest voltage among the plurality of battery cells, wherein the second driving signal includes the voltage signal output by the sampling chip.

5. The equalization circuit according to any one of claims 1 to 4, characterized in that, The first driving signal includes a current signal with a constant current.

6. The equalization circuit according to claim 5, characterized in that, The driving circuit includes multiple second diodes, a first resistor, a second resistor, a first transistor, and a second transistor connected in series. The first end of the multiple second diodes and one end of the second resistor are connected to the output terminal of the boost circuit. The other end of the second resistor is connected to the emitter of the first transistor. The collector of the first transistor is connected to the target switch. The base of the first transistor is connected to the second end of the second diode and one end of the first resistor. The other end of the first resistor is connected to the collector of the second transistor. The base of the second transistor is used to receive a third driving signal. The collector of the second transistor is grounded. The driving circuit is used to output the current signal based on the target voltage and the third driving signal.

7. The equalization circuit according to claim 6, characterized in that, The driving circuit also includes a third resistor, one end of which is connected to the base of the second transistor, and the other end of which is grounded.

8. The equalization circuit according to claim 6, characterized in that, The driving circuit further includes a fourth resistor, one end of which is connected to the base of the second transistor, and the other end of which is used to receive the third driving signal.

9. The equalization circuit according to claim 6, characterized in that, The battery cell to be balanced is the same as the target battery cell, wherein the third driving signal includes the voltage signal inside the sampling chip.

10. The equalization circuit according to claim 6, characterized in that, The target battery cell is the battery cell with the highest voltage among the plurality of battery cells. The third driving signal includes the signal output by the first equalization port, which is the equalization port corresponding to the battery cell to be equalized among the plurality of equalization ports of the sampling chip.

11. The equalization circuit according to any one of claims 1 to 4, characterized in that, The sampling chip includes multiple equalization ports. During the equalization process of the battery cell to be equalized, the first driving signal is used to turn on the first equalization port and the second equalization port among the multiple equalization ports. The target switch includes a first target sub-switch and a second target sub-switch. The first balancing port is connected to the first target sub-switch, the second balancing port is connected to the second target sub-switch, the first target sub-switch is connected to the battery cell to be balanced, and the second target sub-switch is connected to the battery cell adjacent to the battery cell to be balanced.

12. The equalization circuit according to any one of claims 1 to 4, characterized in that, When the voltage of the battery cell to be balanced is greater than the first voltage threshold, the battery cell to be balanced outputs energy to the energy pool. When the voltage of the battery cell to be balanced is less than the second voltage threshold, the energy pool outputs energy to the battery cell to be balanced.

13. An equalization system, characterized in that, include: Multiple battery cells; A switch array is connected to the plurality of individual battery cells; A sampling chip is used to sample the battery parameters of the multiple battery cells; According to any one of claims 1 to 12, the equalization circuit is connected to the sampling chip, and the equalization system controls the equalization circuit through the sampling chip to equalize the battery cells to be equalized among the plurality of battery cells.

14. The equalization system according to claim 13, characterized in that, In the switch array, one switch corresponds to two battery cells among the plurality of battery cells.

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