CN102832667A - Charge-discharge equalizer circuit based on inductive energy storage for series battery pack - Google Patents

Abstract

The invention discloses a charge-discharge equalization circuit for series battery packs based on inductive energy storage. Each battery unit module is connected with a set of equalization subcircuits, the positive terminal VCC and the negative terminal GND of the series battery packs, and the connection point N It is divided into front part and rear part. The number of battery cell modules in the front part is at most one more than the number of battery cell modules in the rear part. The battery cell modules in the front part are odd batteries, and the battery cell modules in the rear part are even batteries. The equalization sub-circuit connected is an odd equalization sub-circuit, and the equalization sub-circuit connected with an even battery is an even equalization sub-circuit. The battery management system sends equalization instructions to the control circuit according to the remaining power of each battery in the battery pack, and the control circuit controls the opening and closing of the upper-bridge MOS tube Q _u or the lower-bridge MOS tube _Qd of the equalization sub-circuit to its corresponding The connected battery is charged and discharged to ensure that each battery does not appear to be overcharged and overdischarged during charging and discharging.

Description

A charge-discharge equalization circuit for series battery packs based on inductive energy storage

technical field

The invention relates to a battery balancing technology, in particular to a balancing circuit of a battery management system of a hybrid electric vehicle or a pure electric vehicle or an energy storage device of an energy storage power station.

Background technique

After multiple charge and discharge cycles of series batteries, the distribution of the remaining capacity (SOC, State of Charge) of each battery unit module will roughly appear in three situations: (1) The remaining capacity (SOC, State of Charge) of individual battery unit modules ) is high; (2) The remaining capacity (SOC, State of Charge) of individual battery cell modules is low; (3) The remaining capacity (SOC, State of Charge) of individual battery cell modules is high and the remaining capacity of individual battery cell modules The capacity (SOC, State of Charge) is low.

For the above three situations, researchers at home and abroad have proposed their own solutions. For example, in case (1), some researchers have proposed a parallel resistor shunt method, which consumes the energy of a battery with a high remaining capacity (SOC, State of Charge) through a resistor by controlling the corresponding switch, and this method wastes energy in vain. and a large amount of heat is generated during the equalization process, which increases the load of battery thermal management. Some researchers have also proposed equalization circuits such as a bidirectional DC-DC equalization method and a coaxial transformer equalization method. These circuits all use transformers, which increases the cost of the equalization circuit.

At present, the equalization control methods of lithium-ion battery packs can be divided into two categories: energy dissipation type and energy non-dissipation type according to the energy consumption of the circuit during the equalization process. According to the classification of equalization function, it can be divided into charge equalization, discharge equalization and dynamic equalization. Charging equalization refers to the equalization during the charging process. Generally, it starts to equalize when the voltage of the battery pack reaches the set value, and reduces the charging current to prevent overcharging. Discharge balance is the balance during the discharge process, and prevents over-discharge by supplementing energy to the single battery with low remaining energy (SOC, State of Charge). The dynamic balance method combines the advantages of charge balance and discharge balance, and balances the battery pack during the entire charge and discharge process, avoiding the problems in single balance.

Contents of the invention

The purpose of the present invention is to provide a charge-discharge equalization circuit for series-connected battery packs based on inductive energy storage used in the battery management system of series-connected battery packs, to ensure that the batteries do not appear overcharged and over-discharged during charging and discharging, and to improve the performance of series-connected batteries. The unbalanced phenomenon of the battery pack can increase the available capacity of the battery pack, reduce the maintenance and replacement of the battery pack in series, prolong the service life of the battery pack, and reduce the cost of hybrid electric vehicles, electric vehicles and energy storage power stations.

In order to achieve the above object, the present invention is achieved through the following technical solutions.

奇电池B_i；后部分串联电池单元模块以连接点N为起点，串联电池组负端（GND）为终点，顺次将电池单元模块记为第一偶电池B₂、第二偶电池B₄、第三偶电池B₆，依此顺次命名，与串联电池组负端（GND）相连接的单元电池为第

偶电池B _j，j为正偶数；所述奇电池的正端连接奇均衡子电路的上桥臂MOS管Q_u的漏极a，负端连接奇均衡子电路的储能电感L的第二端e；所述偶电池的正端连接偶均衡子电路的储能电感L的第二端e，负端连接下桥臂MOS管Q_d的漏极d。 A charge-discharge equalization circuit for a series battery pack based on inductive energy storage, the series battery pack includes more than three battery unit modules connected in series, the charge-discharge equalization circuit includes more than three equalization sub-circuits, each battery unit Each module is connected with an equalization sub-circuit. The series battery pack has a positive terminal (VCC) and a negative terminal (GND). With a connection point N in the series battery pack as the dividing point, the series battery pack positive The battery cell module between the terminal (VCC) and the connection point N is the front part, and the battery cell module between the connection point N and the negative terminal (GND) of the series battery pack is the rear part, and the number of battery cell modules in the front part is the largest The number of battery cell modules in the rear part is one more. The battery cell modules in the front part are called odd batteries, and the battery cell modules in the rear part are called even batteries. The equalization subcircuit connected to the odd battery is called an odd equalization subcircuit. The equalization sub-circuit connected to the even battery is called the equalization sub-circuit; the first part of the series battery cell module starts from the connection point N, and the positive terminal (VCC) of the series battery pack is the end point, and the battery cell module is recorded as the first odd Battery B ₁ , the second odd battery B ₃ , and the third odd battery B ₅ are named in sequence, and the battery cell module connected to the positive terminal (VCC) of the series battery pack is the first

Odd battery B _i ; the latter part of the series battery unit module starts from the connection point N and ends at the negative terminal (GND) of the series battery pack, and sequentially records the battery unit modules as the first even battery B ₂ and the second even battery B ₄ , the third even battery B ₆ , named accordingly, the unit battery connected to the negative terminal (GND) of the series battery pack is the first

The even battery B _j , j is a positive even number; the positive end of the odd battery is connected to the drain a of the upper bridge arm MOS transistor Q _u of the odd equalization subcircuit, and the negative end is connected to the second pole of the energy storage inductance L of the odd equalization subcircuit. terminal e; the positive terminal of the dual battery is connected to the second terminal e of the energy storage inductance L of the dual equalization subcircuit, and the negative terminal is connected to the drain d of the lower bridge arm MOS transistor _Qd .

Further, the equalization sub-circuit includes an upper bridge arm MOS transistor Q _u , a lower bridge arm MOS transistor Q _d and an energy storage inductance L, the source of the upper bridge arm MOS transistor _Qu and the drain of the lower bridge arm MOS transistor Q _d The pole and the first end of the energy storage inductance L are connected, the drain a of the upper bridge arm MOS transistor Q _u , the gate b of the upper bridge arm MOS transistor Q _u , and the gate c of the lower bridge arm MOS transistor Q _d , the drain d of the lower bridge arm MOS transistor _Qd is connected to the second end e of the energy storage inductor L.

Further, the battery unit module is a lead-acid battery, a lithium-ion battery, a nickel-metal hydride battery or a supercapacitor.

Further, the drain d of the lower bridge arm MOS transistor _Qd of the odd equalization subcircuit is connected to the negative terminal GND of the series battery pack, the gate b of the upper bridge arm MOS transistor Q _u , the gate b of the lower bridge arm MOS transistor _Qd Pole c is connected to the control circuit.

Further, the drain a of the upper bridge arm MOS transistor Q _u of the even equalization subcircuit is connected to the positive terminal VCC of the series battery pack, the gate b of the upper bridge arm MOS transistor Q _u , and the gate b of the lower bridge arm MOS transistor Q _d Pole c is connected to the control circuit.

Further, the value of i is 1-59, and the value of j is 2-60.

Further, the control signal of the control circuit is sent by the battery management system to the control circuit according to the remaining power (SOC, State of Charge) of each battery cell module. The upper bridge arm MOS tube Q _u or the lower bridge arm MOS tube Q _d of the sub-circuit is turned on and off to realize the balance of the battery; the upper bridge arm MOS tube Q _u and the lower bridge arm MOS tube Q _d are not turned on at the same time; the odd equalization subcircuit can charge and discharge the odd battery connected to it, and the even equalization subcircuit can charge and discharge the even battery connected to it.

Compared with the prior art, the present invention has the following advantages and technical effects: Since the present invention adopts the above-mentioned equalization circuit (EQU) technology in the battery management system of the battery pack connected in series, it can ensure that each battery does not appear in the process of charging and discharging. Overcharge and overdischarge, improve the unbalanced phenomenon of series battery packs, increase the available capacity of battery packs, reduce maintenance and replacement of series battery packs, prolong the service life of battery packs, and reduce the cost of hybrid vehicles, electric vehicles and energy storage power stations. cost. the

Description of drawings

Fig. 1 is a schematic diagram of a charging and discharging equalization circuit of a series battery pack in an embodiment.

Figure 2 is a schematic diagram of the equalization sub-circuit.

Figure 3 is a charge and discharge equalization circuit diagram of 4 batteries connected in series.

Figure 4 is a charge and discharge equalization circuit diagram of 5 batteries connected in series.

Fig. 5 is a charge and discharge equalization circuit diagram of 14 batteries connected in series.

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but the implementation of the present invention is not limited thereto.

奇电池B_i (i=1,3,5…)（此处是为了表示i为奇数，用省略号表示，不限制最大值，如果一定要最大值，那就到59。即i=1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59），下部分串联电池单元模块以连接点N为起点，负端GND为终点，顺次将电池单元模块记为第一偶电池B₂、第二偶电池B₄、第三偶电池B₆、…（依次类推）、与负端GND相连接的单元电池为第

偶电池B _j（j=2,4,6…）（此处是为了表示j为偶数，用省略号表示，不限制最大值，如果一定要最大值，那就到60。即j=2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,32,36,38,40,42,44,46,48,50,52,54,56,58，60），所述奇电池的正负端分别连接奇均衡子电路的上桥臂MOS管Q_u的漏极a、储能电感L的第二端e，所述偶电池的正负两端分别连接偶均衡子电路的储能电感L的第二端e、下桥臂MOS管Q_d的漏极d。电池管理系统根据电池组内各个单元电池的剩余电量(SOC,State of Charge)给控制电路发送均衡指令，控制电路通过控制奇（偶）均衡子电路的上桥臂MOS管Q_u或下桥臂MOS管Q_d的开通和关断给与其相连接的电池充电或者放电。用实线表示的控制线用于控制均衡奇均衡子电路的上桥臂MOS管Q_u和偶均衡子电路下桥臂MOS管Q_d的开通和关断，给与其相连接的奇（偶）电池放电。用虚线表示的控制线用于控制均衡奇均衡子电路的下桥臂MOS管Q_d和偶均衡子电路上桥臂MOS管Q_u的开通和关断，给与其相连接的奇（偶）电池充电。 In Figure 1, the charging and discharging equalization circuit of the series battery pack, each battery unit module is connected with a set of equalization circuit, at least three battery unit modules are connected in series, the positive terminal VCC and the negative terminal GND of the series battery pack, the series battery pack is divided into the upper part , the lower part, the connection point N between the upper part and the lower part, the series battery unit module from the positive terminal VCC to the connection point N is the upper part, the series battery unit module from the connection point N to the negative terminal GND is the lower part, and the battery unit in the upper part The number of modules is at most one more than the number of battery unit modules in the lower part. The upper part of the battery unit modules is an odd battery, the lower part of the battery unit modules is an even battery, and the equalization subcircuit connected to the odd battery is an odd equalization subcircuit. The equalization sub-circuit connected to even batteries is an even equalization sub-circuit. The upper part of the series-connected battery unit module starts from the connection point N and ends at the positive terminal VCC. The battery unit modules are sequentially recorded as the first odd battery B ₁ , the second The odd battery B ₃ , the third odd battery B ₅ , ... (and so on), the unit battery connected to the positive terminal VCC is the first

Odd battery B _i (i=1,3,5...) (here is to indicate that i is an odd number, expressed with an ellipsis, there is no limit to the maximum value, if the maximum value must be reached, then it is 59. That is, i=1,3 ,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53 , 55, 57, 59), the lower part of the battery unit module connected in series starts from the connection point N and ends at the negative terminal GND. The battery unit modules are sequentially recorded as the first even battery B ₂ , the second even battery B ₄ Three pairs of batteries B ₆ , ... (and so on), the unit battery connected to the negative terminal GND is the first

Even battery B _j (j=2,4,6...) (here is to indicate that j is an even number, represented by an ellipsis, there is no limit to the maximum value, if the maximum value must be reached, then it is 60. That is, j=2,4 ,6,8,10,12,14,16,18,20,22,24,26,28,30,32,32,36,38,40,42,44,46,48,50,52,54 , 56, 58, 60), the positive and negative terminals of the odd battery are respectively connected to the drain a of the upper bridge arm MOS transistor Q _u of the odd equalization sub-circuit, and the second terminal e of the energy storage inductor L, and the The positive and negative ends are respectively connected to the second end e of the energy storage inductance L of the even equalization sub-circuit and the drain d of the lower bridge arm MOS transistor Q _d . The battery management system sends equalization instructions to the control circuit according to the remaining power (SOC, State of Charge) of each unit battery in the battery pack, and the control circuit controls the upper bridge arm MOS transistor _Qu or the lower bridge arm of the odd (even) equalization sub-circuit The turn-on and turn-off of the MOS transistor _Qd charges or discharges the battery connected to it. The control line represented by the solid line is used to control the opening and closing of the upper bridge arm MOS transistor Q _u of the equalization odd equalization sub-circuit and the lower bridge arm MOS transistor Q _d of the even equalization sub-circuit, and give the connected odd (even) The battery is discharged. The control line indicated by the dotted line is used to control the opening and closing of the lower bridge arm MOS transistor Q _d of the equalization odd equalization sub-circuit and the upper bridge arm MOS transistor Q _u of the even equalization sub-circuit, and give the odd (even) battery connected to it Charge.

The battery management system is a single-chip microcomputer (such as C8051F340) as the core, and generally has functions such as battery status detection, battery status analysis, battery safety protection, energy control management, and battery information management. For different applications, the battery management system should have different functions. The implementation of the control circuit is a conventional technology in the field, not the content of the present invention. The control circuit has an electrical isolation function, such as optocoupler isolation or transformer isolation of TLP521-1, to convert the control signal sent by the battery management system into It can directly drive the driving circuit signal of the MOS transistor Q _u of the upper bridge arm and the MOS transistor Q _d of the lower bridge arm. It is clear to those skilled in the art that the inductance value of the energy storage inductance L of the odd equalization sub-circuit and the even equalization sub-circuit is determined according to specific requirements. The frequency of the control signal of the control circuit depends on the inductance value of the controlled odd (even) equalization sub-circuit energy storage inductance L, the switching loss of the upper bridge arm MOS transistor Q _u and the lower bridge arm MOS transistor Q _d , and the battery unit It depends on the voltage of the module and the capacity of the battery unit module. The duty cycle of the control signal of the control circuit should reset the energy storage inductance L of the odd (even) balancing sub-circuit in each signal period, that is, the current of the energy storage inductance L starts to rise from zero and finally drops to zero.

For the odd battery B _i and the odd equalization sub-circuit S _i (i=1,3,5...), the upper bridge arm MOS transistor Q _u , the lower bridge arm MOS transistor Q _d , and the energy storage inductance L are included. When the upper bridge arm MOS transistor _Qu is turned on, the current of the energy storage inductor L rises, and the energy storage inductor L stores energy; when the upper bridge arm MOS transistor _Qu is turned off, the energy storage inductor L passes through the lower bridge arm MOS transistor Q _d The body diode freewheels, and the battery _Bi discharges. When the lower bridge arm MOS transistor Q _d is turned on, the current of the energy storage inductor L rises, and the energy storage inductor L stores energy; when the lower bridge arm MOS transistor Q _d is turned off, the energy storage inductor L passes through the body of the upper bridge arm MOS transistor Q _u The diode continues to flow, and the battery Bi _is charged.

For the upper bridge arm MOS transistor Q _u , the lower bridge arm MOS transistor Q _d , and the energy storage inductance L included in the even battery B _j and the even equalization sub-circuit S _j (j=2,4,6...). When the upper bridge arm MOS transistor _Qu is turned on, the current of the energy storage inductor L rises, and the energy storage inductor L stores energy; when the upper bridge arm MOS transistor _Qu is turned off, the energy storage inductor L passes through the lower bridge arm MOS transistor Q _d The body diode freewheels, and the battery _Bj is charged. When the lower bridge arm MOS transistor Q _d is turned on, the current of the energy storage inductor L rises, and the energy storage inductor L stores energy; when the lower bridge arm MOS transistor Q _d is turned off, the energy storage inductor L passes through the body of the upper bridge arm MOS transistor Q _u The diode continues to flow, and the battery _Bj is discharged.

In Figure 5, during the discharge process of the series battery pack, the battery management system detects that the remaining power (SOC, State of Charge) of the first odd battery B ₁ and the second even battery B ₄ is low, in order to prevent the first odd battery B _1. The second even battery _B4 is over-discharged, the battery management system sends an instruction to the control circuit, and the control circuit controls the lower bridge arm MOS transistor _Qd of the odd equalization sub-circuit _S1 connected to the first odd battery _B1 and the second The upper-arm MOS tube _Q of the even equalization sub-circuit _S4 of the even battery _B4 is turned on and off at a certain frequency and duty cycle, and the frequency and duty cycle of the switch are set according to the specific circuit.

When the lower bridge arm MOS transistor _Qd of the odd equalization subcircuit _S1 connected to the first odd battery _B1 is turned on, all the even batteries and the storage tanks of the odd equalization subcircuit _S1 connected to the first odd battery _B1 The energy inductor L and the lower bridge arm MOS tube Q _d form a loop, the current flowing through the energy storage inductor L rises from zero, all the even batteries charge the energy storage inductor L, and the energy storage inductor L stores energy; when combined with the first odd battery When the lower bridge arm MOS transistor _Qd of _the odd equalization subcircuit _S1 connected to B1 is turned off, the energy storage inductance _L and the upper bridge arm MOS transistor of the odd equalization subcircuit _S1 connected to the first odd battery B1 The body diode of Qu _u and the first odd battery _B1 form a loop, and the current of the energy storage inductance L passes through the body diode of the upper-arm MOS transistor Qu _u of the odd equalization sub-circuit _S1 connected to the first odd battery _B1 . To charge the first odd battery _B1 , the current flowing through the energy storage inductor L drops, and at the end of the switching cycle, the current flowing through the energy storage inductor L drops to zero, and the inductor resets.

When the upper bridge arm MOS tube Q _u of the even equalization subcircuit _S4 connected to the second even battery _B4 is turned on, the second even battery _B4 , all the odd batteries, and the even batteries connected to the second even battery _B4 The energy storage inductor L of the equalization sub-circuit _S4 and the upper bridge arm MOS transistor Q _u form a loop, the current flowing through the energy storage inductor L rises from zero, and the first even battery _B2 and all the odd batteries charge the energy storage inductor L , the energy storage inductance L stores energy; when the upper bridge arm MOS transistor Q _u of the even equalizer subcircuit _S4 connected to the second even battery _B4 is turned off, the even equalizer connected to the second even battery _B4 The energy storage inductance L of the circuit _S4 , the body diode of the MOS transistor _Qd of the lower bridge arm, and the second even battery _B4 form a loop, and the current of the inductance passes through the even balance sub-circuit _S4 connected to the second even battery _B4 The body diode of the lower bridge arm MOS transistor Q _d freewheels to charge the second dual battery B ₄ , the current flowing through the energy storage inductor L drops, and at the end of the switching cycle, the current flowing through the energy storage inductor L drops to zero , the energy storage inductance L is reset.

In Figure 5, during the charging process of the series battery pack, the battery management system detects that the remaining power (SOC, State of Charge) of the first odd battery B ₁ and the second even battery B ₄ is too high, in order to prevent the first odd battery B _1. The second even battery _B4 is overcharged, the battery management system sends an instruction to the control circuit, and the control circuit controls the upper bridge arm MOS transistor _Q of the odd equalization sub-circuit _S1 connected to the first odd battery _B1 and the second The MOS transistor Q _d of the lower bridge arm of the even equalization sub-circuit S ₄ of the even battery B ₄ is turned on and off at a certain frequency and duty cycle, and the frequency and duty cycle of the switch are set according to the specific circuit.

When the upper bridge arm MOS tube _Q of the odd equalization subcircuit _S1 connected to the first odd battery _B1 is turned on, the first odd battery _B1 , the odd equalization subcircuit S connected to the first odd battery _B1 The energy storage inductance L of ₁ and the upper bridge arm MOS tube Q _u form a loop, the energy storage inductance L absorbs the charging current of the first odd battery B ₁ , the current flowing through the inductance L starts from zero, and the first odd battery B ₁ The charging current decreases, and the energy storage inductance L stores energy; when the upper bridge arm MOS tube _Q of the odd equalization sub-circuit _{S 1} connected to the first odd battery B ₁ is turned off, the The energy storage inductance L of the odd balance sub-circuit _S1 , the body diode of the lower bridge arm MOS transistor _Qd , and all even batteries form a loop, and the current of the energy storage inductance L passes through the odd balance subcircuit connected to the first odd battery _B1 The body diode of the MOS transistor Q _d in the lower bridge arm of S ₁ freewheels to charge all the dual batteries, and the current flowing through the energy storage inductor L drops, and at the end of the switching cycle, the current flowing through the energy storage inductor L drops to zero , the energy storage inductance L is reset.

When the lower bridge arm MOS transistor _Qd of the even equalization subcircuit _S4 connected to the second even battery _B4 is turned on, the second even battery _B4 , the even equalization subcircuit S connected to the second even battery _B4 The energy storage inductance L of ₄ and the lower bridge arm MOS tube Q _d form a loop, the energy storage inductance L absorbs the charging current of the battery _B4 , and the current flowing through the energy storage inductance L rises from zero, and the charging of the second dual battery _B4 The current decreases, and the energy storage inductance L stores energy; when the lower bridge arm MOS transistor _Qd of the even equalization subcircuit _S4 connected to the second even battery _B4 is turned off, the even connected to the second even battery _B4 The energy storage inductance L of the equalization sub-circuit S ₄ and the body diode of the lower bridge arm MOS transistor Q _u , the first even battery B ₂ , and all the odd batteries form a loop, and the current of the energy storage inductance L passes through the phase with the second even battery B ₄ The body diode of the upper bridge arm MOS transistor _Qu of the connected even equalization sub-circuit _S4 freewheels to charge the first even battery and all the odd batteries, and the current flowing through the energy storage inductor L decreases. When the switching cycle ends, The current flowing through the energy storage inductor L drops to zero, and the energy storage inductor L is reset.

Claims (7)

1. A charge-discharge equalization circuit for series battery packs based on inductive energy storage, said series battery packs comprising more than three battery cell modules connected in series, characterized in that said charge-discharge equalization circuit comprises more than three equalization sub-circuits , each battery cell module is connected with an equalization sub-circuit respectively, the series battery pack has a positive terminal (VCC) and a negative terminal (GND), and a connection point N in the series battery pack is used as a dividing point, so The battery cell module between the positive terminal (VCC) of the series battery pack and the connection point N is the front part, and the battery cell module between the connection point N and the negative terminal (GND) of the series battery pack is the rear part. The number of modules is at most one more than the number of battery cell modules in the rear part. The battery cell modules in the front part are called odd batteries, and the battery cell modules in the rear part are called even batteries. The equalization subcircuit connected to the odd batteries is called The odd balance sub-circuit, the balance sub-circuit connected with the even battery is called the balance sub-circuit; the first part of the series battery cell module starts from the connection point N, and the positive terminal (VCC) of the series battery pack is the end point, and the battery cell modules are connected in sequence Denote as the first odd battery B ₁ , the second odd battery B ₃ , and the third odd battery B ₅ , and name them in sequence. The battery unit module connected to the positive terminal (VCC) of the series battery pack is the first

Odd battery B _i ; the latter part of the series battery unit module starts from the connection point N and ends at the negative terminal (GND) of the series battery pack, and sequentially records the battery unit modules as the first even battery B ₂ and the second even battery B ₄ , the third even battery B ₆ , named accordingly, the unit battery connected to the negative terminal (GND) of the series battery pack is the first

The even battery B _j , j is a positive even number; the positive end of the odd battery is connected to the drain (a) of the upper bridge arm MOS transistor (Q _u ) of the odd equalization subcircuit, and the negative end is connected to the energy storage inductance of the odd equalization subcircuit The second terminal (e) of (L); the positive terminal of the dual battery is connected to the second terminal (e) of the energy storage inductance (L) of the dual equalization sub-circuit, and the negative terminal is connected to the lower bridge arm MOS tube (Q _d ) The drain (d). 2. The charge-discharge equalization circuit for a series battery pack according to claim 1, wherein the equalization sub-circuit includes an upper bridge arm MOS transistor (Q _u ), a lower bridge arm MOS transistor (Q _d ) and an energy storage inductance (L), the source of the upper bridge arm MOS tube (Q _u ), the drain of the lower bridge arm MOS tube (Q _d ), and the first end of the energy storage inductor (L) are connected, and the upper bridge arm MOS tube (Q _u ), the gate (b) of the upper bridge arm MOS transistor (Q _u ), the gate (c) of the lower bridge arm MOS transistor (Q _d ), the lower bridge arm MOS transistor (Q The drain (d) of _d ) is connected to the second terminal (e) of the energy storage inductor (L). 3. The charge-discharge equalization circuit for series-connected battery packs according to claim 1, wherein the battery unit modules are lead-acid batteries, lithium-ion batteries, nickel-metal hydride batteries or supercapacitors. 4. The equalization circuit for series battery packs according to claim 1, characterized in that the drain (d) of the lower bridge arm MOS transistor (Q _d ) of the odd equalization sub-circuit is connected to the negative terminal (GND) of the series battery pack , the gate (b) of the upper bridge arm MOS transistor (Q _u ), and the gate (c) of the lower bridge arm MOS transistor (Q _d ) are connected to the control circuit. 5. The charge-discharge equalization circuit for series battery packs according to claim 1, characterized in that the drain a of the MOS transistor (Q _u ) of the upper bridge arm of the even balance sub-circuit is connected to the positive terminal (VCC) of the series battery pack , the gate (b) of the upper bridge arm MOS transistor (Q _u ), and the gate (c) of the lower bridge arm MOS transistor (Q _d ) are connected to the control circuit. 6. The charge-discharge equalization circuit for series battery packs according to claim 1, wherein the control signal of the control circuit is an equalization instruction sent by the battery management system to the control circuit according to the remaining power of each battery cell module, and controls The circuit accepts the instructions of the battery management system to control the opening and closing of the upper bridge arm MOS transistor (Q _u ) or the lower bridge arm MOS transistor (Q _d ) of the odd and even equalization sub-circuits to achieve battery equalization; the same odd and even equalization sub-circuit The upper bridge arm MOS tube (Q _u ) and the lower bridge arm MOS tube (Q _d ) of the circuit are not turned on at the same time; the odd equalizer subcircuit can charge and discharge the odd battery connected to it, and the even equalizer subcircuit The circuit can charge and discharge the dual battery connected to it. 7. The charge-discharge equalization circuit for series battery packs according to claims 1-6, characterized in that the value of i is 1-59, and the value of j is 2-60.

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