CN114928127A

CN114928127A - Modular battery system and equalization control method

Info

Publication number: CN114928127A
Application number: CN202210364199.0A
Authority: CN
Inventors: 何亮明
Original assignee: Jiaxing Sustainable New Energy Co Ltd
Current assignee: Jiaxing Sustainable New Energy Co Ltd
Priority date: 2022-04-07
Filing date: 2022-04-07
Publication date: 2022-08-19
Anticipated expiration: 2042-04-07
Also published as: CN114928127B

Abstract

The invention relates to a modular battery system and a balanced scheduling method, which comprises a battery module or a plurality of battery modules which are connected in series, wherein each battery module is provided with a plurality of storage batteries, a switch array and a driving circuit, and a battery state parameter detection and charge-discharge balanced scheduling module. The switch array can allow each storage battery to be independently connected into or disconnected from the power main loop; the battery state parameter detection module realizes measurement, processing and storage of signals such as battery monomer voltage, module current and the like; the charge and discharge balance scheduling module performs battery scheduling optimization by using the local battery state information of the module, and determines the idle parameters of the battery by using the real-time electric quantity and capacity information of the battery or the voltage information of multiple charge and discharge cycles, thereby achieving the purpose of battery balance. The battery system modules are completely independent, any communication function and system master control are not needed, one-to-one replacement of a traditional lead-acid storage battery can be achieved, compatibility is strong, requirements for consistency of the battery cells are low, and the battery system module is suitable for wide fields such as gradient utilization of power batteries.

Description

Modular battery system and equalization control method

Technical Field

The invention relates to a control system for a battery pack, in particular to a high-reliability, extensible and modularized battery system constructed by using a switch array and a distributed control method, which reduces the requirement on the consistency of a battery cell and is suitable for the wide fields of gradient utilization of power batteries and the like.

Background

The Battery Management System (BMS) ensures that each parameter of the battery is within a safety range by monitoring each state parameter of the battery, and avoids safety risks such as overcharge, overdischarge or overheating of the battery. Generally, the capacities of the respective cells in the series-connected battery pack may be slightly different or the states of charge (SOC) thereof may be different due to self-discharge. Most of the existing battery management system schemes stop discharging when a certain battery in a battery pack is discharged, although other batteries may not be completely discharged; or a battery in a battery pack is fully charged, the entire battery pack is stopped from being charged, although other batteries may not be fully charged. Thus, there is a significant "tub slap effect" that reduces the actual available capacity of the battery.

To reduce the effects of battery inconsistencies, passive equalization or active equalization techniques may be used. The passive balance has the problems of small balance current, difficult heat dissipation and the like; active equalization usually requires power devices such as a large-capacity capacitor, an inductor or a transformer, and the like, and has the disadvantages of complex circuit, high control difficulty and poor reliability. By applying the switch array technology, the connection relation between the batteries can be dynamically adjusted, and the switch array technology becomes another novel way for solving the short plate effect of the batteries. Patent US6140799 provides a battery switch array topology, each battery (combination) uses 3 switches, can realize the dynamic connection functions such as series connection, parallel connection and bypass of battery. Patent US8330419B2 provides a more complex switch array of 6 switches, allowing a richer dynamic cell connection. The more the number of switches is, the more flexible the battery connection is, but the realization is complex, and the battery connection is often not economical, and is not beneficial to commercial application and popularization. In addition, the battery needs to be charged and discharged, and bidirectional current exists, which brings great challenges to the switching device model selection. The mechanical switch has the advantage of bidirectional controllable current, but has large volume and short service life. Semiconductor solid-state switches such as MOSFETs are often small in size and convenient to drive and control, but can only control current in one direction, and therefore 2 devices are required to implement one switching function. For example, patent CN103915656B provides a battery module solution based on 4 MOSFET switching devices, which can implement the battery series and bypass functions, and provides a battery protection method based on the comparison of battery parameter threshold.

Moreover, most of the prior art belongs to a centralized integrated scheme, and a large number of power supply power lines and communication signal lines are arranged between internal modules, so that the production, the transportation and the after-sale maintenance are not facilitated. Meanwhile, the product has poor expandability, and often the voltage specification of the battery system is changed, and then the development must be re-established, so that the model management and control of enterprise research and production are complex and the cost is high.

Disclosure of Invention

In order to further solve the above problems, the present invention provides a modular battery system and a balance control scheduling method, which make full use of the bypass function and the distributed control method of the switch array to realize standard modularization of the battery system, and can be serially expanded to construct a high voltage system, thereby facilitating production and after-sales maintenance.

The invention aims to provide a battery system formed by connecting one battery module or a plurality of battery modules in series, wherein the battery module comprises F (F is more than or equal to 1) storage batteries, a switch array and driving circuit, and a battery state parameter detection and charge-discharge balance scheduling module; the switch array comprises 2 x F MOSFET devices, and each storage battery can be independently connected into or disconnected from the power main loop; the battery state parameter detection module is used for acquiring, processing and storing battery state information such as battery voltage, current, electric quantity and capacity; the charge-discharge balancing scheduling module performs idle parameter calculation and battery time domain scheduling only by using local battery state information of the module to achieve the purpose of battery balancing; the battery modules are completely independent, no communication function is needed between the modules, and extra battery system master control is also not needed.

The storage battery can be a single battery cell or a battery pack formed by series-parallel connection of various physical or chemical storage batteries such as a lithium metal battery, a lithium ion battery, a sodium ion battery, a fuel battery, a nickel-hydrogen battery, a nickel-cadmium battery or a solar battery.

The battery system is composed of standardized battery modules with completely consistent software and hardware, no other communication cables are needed between the battery modules except for positive and negative power supply leads, and the battery system is similar to a series connection application mode of a traditional lead-acid storage battery, and the characteristics bring great convenience to product design, production, field installation, after-sale maintenance and the like. For example, if the nominal voltage of the battery module is 12V, a rich product spectrum with different voltage specifications such as 24V, 36V, 48V and the like can be formed by connecting different numbers of battery modules in series. Moreover, the small module building blocks are adopted to build a large-scale battery system in an accumulation mode, and production management, transportation and carrying are facilitated. Especially for some equipment vehicles with battery bins dispersed at different positions, the conventional integrated batteries cannot be matched and placed, and the advantage of the scheme of the invention is highlighted at the moment. In addition, the battery module does not need to communicate with the outside or encode, is powered by the battery module, only needs local battery information for a related balanced scheduling algorithm, and belongs to a completely 'autonomous' system. Therefore, the fault module can be directly replaced during after-sale maintenance without considering system software update. Because the battery module has powerful homoenergetic performance, need not the electric quantity during the replacement even and match, it is extremely convenient.

In a preferred embodiment, the battery module stack consists of 5 secondary batteries B1, B2, B3, B4, B5; the switch array is composed of 10N-type MOSFET devices Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, wherein a drain of Q1 is connected to a positive electrode of a battery B1, a source of Q1 is connected to a drain of Q1, a source of Q1 is connected to a negative electrode of the battery B1, a drain of Q1 is connected to a positive electrode of the battery B1, a source of Q1 is connected to a drain of the battery B1, a source of Q1 is connected to a negative electrode of the battery B1, a drain of Q1 is connected to a source of the battery B1, a drain of Q1 is connected to a positive electrode of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B1 is connected to the battery B1, a drain of the battery B1 is connected to the battery B1, a drain of the battery B1, and a drain of the battery B1, a drain of the battery B1 is connected to the battery B1, a drain of the battery B1, a drain of, the source of Q5 is connected to the drain electrode of Q7, and battery B4's positive pole is connected to battery B5's negative pole, and the positive pole of battery module is connected to the source of Q9, and the negative pole of battery module is drawn forth from battery B1's negative pole.

On average, each battery of the switch array only needs two MOSFET devices, only 1.8 power leads are needed between the galvanic pile and the BMS on average, and on the premise of ensuring that each battery can be independently connected and disconnected from the flexible function of the power main loop, the inside of the galvanic pile of the battery module forms a fixedly connected rigid small battery pack with higher voltage, thereby providing convenience for the design of a driving circuit.

In a preferred embodiment, the switch array is made up of five sets of complementary switches Q1/Q2, Q3/Q4, Q5/Q6, Q7/Q8, Q9/Q10. Each group of complementary switches is controlled by two output signals of the balanced scheduling module through a level transfer circuit, wherein one signal directly controls one switch, and the other signal controls the other switch after passing through a double-input NOR gate. Two MOSFET devices in the complementary switch are in an inverted state, and dead zone control time needs to be introduced when the switch states are switched so as to prevent the two switches from being simultaneously conducted to cause external short circuit of the battery. When one input signal is high level, the NOR gate outputs low level no matter the other input signal is high level or low level, and the dual-input NOR gate plays a role in turning off the corresponding MOSFET.

In a preferred embodiment, the high voltage signal of the level shift circuit of the switch array driving circuit is derived from a voltage doubling circuit of a battery pack after batteries B4 and B5 are connected in series.

The position of each battery in the battery module in the power main loop is dynamically changed along with different configuration states of the switch array, so that the source and the drain of the related MOSFET device are always in a floating state, and the change amplitude of the ground potential is large. In order to ensure reliable control of the MOSFETs in all situations, the high voltage supply of the driver circuit must be higher than the source potential of all the MOSFET devices. In order to meet the requirements, a battery pack with B4 and B5 connected in series and close to the anode of the battery module is selected, and a voltage doubling circuit is realized by using a charge pump controller to generate a high-voltage power supply of a driving circuit. The voltage doubling circuit takes the cathode of the battery B4 as a reference ground, the output voltage is higher than the anode of the battery B5 (the voltage of the battery pack after the battery B4 and the battery B5 are connected in series is removed by a diode drop), and all 10 MOSFETs in the switch array can be driven.

In another preferred embodiment, the battery module cell stack consists of 5 secondary batteries B11, B12, B13, B14, B15; the switch array is composed of 10P-type MOSFET devices Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18, Q19, Q20, wherein the drain of Q11 is connected to the cathode of battery B11, the source of Q11 is connected to the drain of Q11, the source of Q11 is connected to the anode of battery B11, the drain of Q11 is connected to the cathode of battery B11, the source of Q11 is connected to the drain of Q11, the source of Q11 is connected to the anode of battery B11, the source of Q11 is connected to the cathode of battery B11, the drain of Q11 is connected to the drain of Q11, the drain of Q11 is connected to the cathode of battery B11, the drain of battery B11 is connected to the drain of battery B11, the drain of the battery B11 is connected to the drain of the battery B11, the drain of the Q11, the drain of the battery B11 is connected to the battery B11, the drain of the battery B11, the Q11, the drain of the battery B11 is connected to the drain of the battery B11, the drain of the battery B11, the drain of the battery B11, the battery B11 is connected to the battery B11, the drain of the battery B11, the battery B11 is connected to the battery B11, the drain of the battery B11, the drain of the battery B11, the drain of the battery B11, the drain of the battery B11 is connected to the battery B11, the drain of the battery B11, the drain of the battery B, the source of Q19 is connected with the drain electrode of Q17, and battery B13's positive pole is connected with battery B14's negative pole, and battery module's negative pole is connected with the source of Q11, and battery module's positive pole is drawn from battery B15's positive pole.

In a preferred embodiment, the switch array is composed of five groups of complementary switches Q11/Q12, Q13/Q14, Q15/Q16, Q17/Q18 and Q19/Q20, two switches in each group of complementary switches cannot be conducted simultaneously, two output signals of the balanced scheduling module are controlled by a level shift circuit, one signal directly controls one switch, and the other signal controls the other switch after a double-input NAND gate.

In a preferred embodiment, the negative power supply of the level shift circuit of the switch array driving circuit is obtained by a battery pack formed by connecting batteries B11 and B12 in series through a negative voltage circuit.

Similar to the N-type MOSFET scheme, with a switch array of P-type MOSFET devices, only two MOSFET devices per cell are required on average, and only 1.8 power leads are required between the cells and the BMS on average. The negative voltage required by the driving of the P-type MOSFET is generated by using a negative voltage circuit constructed by a charge pump controller by using a battery pack with B11 and B12 connected in series close to the negative electrode of the battery module. The dead zone control of the complementary switch is realized by using an NAND gate instead, and the dead zone state can be entered when a low level is input.

The number of the batteries of the battery module connected into the main loop can be dynamically adjusted through the switch array, so that on one hand, the overcharged and overdischarged batteries can be protected in time on the premise of not cutting off the power supply of a system; on the other hand, more batteries than required by voltage specifications can be configured in the battery module, certain redundancy is formed, and a battery time domain scheduling is applied to realize a battery balancing function. However, from the viewpoint of the external load and the charging equipment, it is desirable that the voltage fluctuation of the battery module is as small as possible, that is, the variation in the number of batteries connected to the battery module is as small as possible. In order to achieve the above object, the present invention provides a charge-discharge balance control scheduling method based on battery power and capacity information, comprising the following steps:

initializing parameters, wherein the number of the batteries of the battery module, which need to be accessed into the power main loop, is M, and continuously monitoring the battery state parameters in real time.

And selecting characteristic variables, judging the charging and discharging states of the battery module according to the current direction, and making the variable R equal to the battery electric quantity when the battery module is discharged, and making the variable R equal to the charging quantity required by the battery (namely, subtracting the existing electric quantity from the battery capacity) when the battery is charged.

Analyzing characteristic variables, and sequentially arranging R values of all F batteries of the battery module in a descending order to be R ₁ 、R ₂ …R _M …R _F . If with R _M As the center, there are K number and R _M Same (F-M is more than or equal to K is more than or equal to 0), namely R _M ＝R _M+1 ＝R _M+2 …＝R _M+K (ii) a When viewed from left, there are E number and R _M Same (M-1. gtoreq. E. gtoreq. 0), namely R _M ＝R _M－1 ＝R _M－2 …＝R _M－E 。

Judging and relevant operations according to the conditions, sequentially judging the following 4 conditions, and selecting the first met relevant operation to execute. Condition (a): when E, K takes the maximum value at the same time, i.e., E + K +1 ═ F, indicating that the battery is already in the equilibrium state, operation (a): sequentially selecting F-M batteries from the F batteries, placing the other batteries in a main loop for charging and discharging, and changing R every time R changes _M When F is F-M)/(M is W) (wherein W is the common multiple of F-M and F), selecting the batteries again in sequence for idle running till F batteries are fully charged or fully discharged after W/K switching; condition (b): when K is the minimum value 0, operation (b): the first M batteries (after being sorted according to R value) are selected for charging and discharging, and othersThe battery enters an idle state until R _M After the value is changed with R _M+1 The same is carried out until the two are identical; condition (c): when (R) _M－E－1 －R _M+K+1 )/(R _M －R _M+K+1 ) And (c) when the ratio of E + K +1 to E +1 is not less than (E + K +1) or E is the maximum value M-1: sequentially selecting K batteries from the E + K +1 batteries, idle-placing the K batteries, connecting other batteries into the main loop for charging and discharging, and enabling the R value change amount to reach K (E + K +1) × (R) every time _M －R _M+K+1 ) and/(W + E +1)) (wherein W is a common multiple of K and (E + K +1)), the batteries are selected again in sequence for idle running until R values and R values of the E + K +1 batteries are switched for W/K times _M+K+1 The same is carried out until the two are identical; condition (d): when (R) _M－E－1 －R _M+K+1 )/(R _M －R _M+K+1 )<(E + K +1)/(E +1) or K is the maximum F-M, the operation (d): k batteries are sequentially selected from the E + K +1 batteries and put in idle state, other batteries are connected into the main loop to be charged and discharged, and the R value of each battery changes (R value is changed) _M－E－1 －R _M ) When the voltage of the battery is equal to or higher than the voltage of the battery, when the voltage of the battery is equal to or lower than the voltage of the battery, the battery is selected to be idle for rest again in sequence when the voltage of the battery is equal to or lower than the voltage of the battery (E + K +1)/W (wherein W is the common multiple of K and (E + K +1)), and the R value of the E + K +1 battery are switched for W/K times _M－E－1 As such.

Fifthly, returning to the step II, and circulating operation.

The battery capacity and the real-time electric quantity cannot be directly measured, the battery capacity and the real-time electric quantity must be indirectly measured and calculated through current integration or impedance inversion and other modes, and factors such as environmental temperature, load working conditions, battery aging and the like need to be considered for calibration, so that the calibration is difficult and high in cost. For some small and medium-sized applications, it may not be economical. In order to solve the above problems, the present invention provides a battery scheduling method based on heuristic algorithm, which only needs to use battery voltage information, and comprises the following steps:

initializing charge and discharge idle parameters, determining the number M of batteries required to be connected into a power main loop and the number F-M of idle batteries, and continuously monitoring the state parameters of the batteries in real time.

Except for the batteries in the overcharge or over-discharge protection state, all the batteries apply fixed idle parameters to be in turn, and the on-off state of each battery is updated gradually.

Updating the idle parameter, and increasing the charging idle parameter T of a certain battery if the battery first reaches the over-charging protection voltage when in charging _new ＝T _old + α, correspondingly lowering the charge vacancy parameter T of the other battery _new ＝T _old - α/(F-1); when the battery is in discharge, if a certain battery first reaches the over-discharge protection voltage of the battery, the discharge vacancy parameter D of the battery is increased _new ＝D _old + beta, correspondingly reducing the discharge vacancy parameter D of the other cells _new ＝D _old －β/(F－1)。

Returning to the step

And (4) circulating operation.

The battery system provided by the invention has the advantages of standardization and modularization, and is convenient for large-scale production and system field installation and debugging. Meanwhile, building blocks can be built and applied, series type products can be derived by adjusting the number of the battery modules, and the lead-acid storage battery has the usability, compatibility and maintainability of the traditional lead-acid storage battery.

Compared with the prior art, the invention mainly has the following three advantages: firstly, the number of MOSFET devices required by a switch array is reduced by half, the number of power leads between a pile and a BMS is reduced by 20%, and a system power supply and a switch driving voltage are completely generated from the inside of a battery module without an auxiliary power supply, so that the independence is strong; secondly, the battery idle parameters are optimized and calculated by using the real-time electric quantity and capacity information of the battery or the voltage information of multiple charge-discharge cycles, the time domain scheduling of the battery is carried out, the balance performance is outstanding, the requirement on the consistency of the battery is greatly reduced, and the cost control and the application field expansion are facilitated; finally, the battery modules are completely independent, no communication function is needed, and no additional system master control module is needed, so that the standardized mass production, field installation and construction and after-sale maintenance and replacement are facilitated, and a foundation is laid for industrial application and popularization.

Drawings

Fig. 1 shows a schematic structural diagram of a modular battery system provided by the present invention.

Fig. 2 is a schematic diagram of a battery switch array formed by using N-type MOSFET devices according to the present invention.

Fig. 3 is a functional example of a battery switch array formed by using N-type MOSFET devices according to the present invention.

Fig. 4 is a schematic diagram of a battery switch array driving circuit formed by using N-type MOSFETs according to the present invention.

Fig. 5 is a high-voltage power circuit diagram of a battery switch array driving circuit formed by using N-type MOSFETs according to the present invention.

Fig. 6 shows a schematic diagram of a battery switch array composed of P-type MOSFET devices according to the present invention.

Fig. 7 shows a schematic diagram of a driving circuit of a battery switch array formed by P-type MOSFET devices according to the present invention.

Fig. 8 shows a negative power circuit diagram of a battery switch array driving circuit composed of P-type MOSFETs according to the present invention.

Fig. 9 shows a charge-discharge balance scheduling method based on battery power and capacity according to the present invention.

Fig. 10 shows a charge-discharge equalization scheduling method based on battery voltage under a multi-cycle working condition provided by the invention.

Detailed Description

In order to make the objects, technical solutions and advantageous technical effects of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, the present invention provides a modular battery system, which is formed by one battery module or a plurality of battery modules that are serially connected and expanded. The battery module 101 has a separate housing, for example a standard chassis or a plastic housing like a 12V lead-acid battery. Only the positive and negative electrodes of the battery are connected with the lead wires between different battery modules, and no communication line is needed. The number of the battery modules of the battery system is theoretically unlimited and can be flexibly configured according to application requirements. The battery system also does not need to be provided with an additional system master controller, the battery module can be directly connected with an external load or a charger to carry out charging and discharging after being connected with the positive and negative leads, and the functions of battery charging and discharging protection, balanced dispatching and the like are completely and independently realized by the battery module. The battery module 101 is composed of a stack 102 of F secondary batteries and a Battery Management System (BMS)106, wherein positive and negative leads of the secondary batteries are electrically connected to the battery management system 106. The main functional modules of the battery management system 106 include a battery state parameter detection 103, a switch array and driving circuit 104, and a battery charge-discharge balance scheduling control 105. The switch array 104 realizes independent connection or disconnection of each storage battery to or from a power main loop through 2 × F MOSFET devices; the battery state parameter detection module 103 measures, processes, and stores signals such as the voltage, the electric quantity, and the capacity of a battery cell, and the current of a battery module, so that the charge and discharge balance control module 105 runs a relevant algorithm. The algorithm only uses the local battery state information of the battery module to carry out battery scheduling optimization so as to achieve the purposes of battery protection, balance and the like.

As shown in fig. 2, the present invention provides a battery switch array implementation scheme using N-type MOSFET devices, which can provide dynamic connection services for 5 batteries B1, B2, B3, B4, and B5. The switch array is composed of 10N-type MOSFET devices Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, and Q10, wherein a drain of Q1 is connected to a positive electrode of a battery B1, a source of Q1 is connected to a drain of the battery B1, a source of the battery B1 is connected to a negative electrode of the battery B1, a drain of the Q1 is connected to a source of the battery B1, a drain of the Q1 is connected to a positive electrode of the battery B1, a source of the Q1 is connected to a drain of the battery B1, a source of the battery B1 is connected to a drain of the battery B1, a drain of the Q1 is connected to a positive electrode of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B1 is connected to a negative electrode of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B1 is connected to a negative electrode of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B1 is connected to a drain of the battery B1, a drain of the battery B is connected to a drain of the battery B1, a drain of the battery B72, a drain of the battery B1 is connected to a drain of the battery B1, a battery B72, a drain of the battery B1, a drain of the battery B72, a drain of the battery, the source of Q5 is connected with the drain of Q7, and the positive pole of battery B4 is connected with the negative pole of battery B5, and the positive pole of battery module is connected with the source of Q9, and the negative pole of battery module is drawn from the negative pole of battery B1.

The battery switch array scheme requires two N-type MOSFET devices per battery, one of which allows the battery to be switched into the main loop and the other allows the battery to be switched out of the main loop. The parasitic diodes of the two MOSFET switches are connected in reverse to avoid forming a loop to cause a short circuit outside the battery. As shown in fig. 2, taking a battery B5 as an example, when Q9 is turned on and Q10 is turned off, B5 is connected to the main circuit and can be charged and discharged; when Q9 is disconnected and Q10 is connected, B5 is out of the main loop and is in a bypass resting state, but the charging and discharging processes of other batteries are not influenced; when both Q9 and Q10 are turned off at the same time, i.e., a dead zone state is entered, the battery B5 may be charged through the parasitic diode of Q9, or the battery module may be discharged through the parasitic diode of Q10. Because the parasitic diode has larger follow current voltage drop, the MOSFET generates larger heat, dead time needs to be controlled, and the switching speed and the heat dissipation performance are optimized. Fig. 3 is an example of the function implementation of a battery module, in which the charge/discharge balancing control module makes the battery B1 go out of the main circuit, the batteries B2, B3, B4, and B5 are connected to the main circuit for charging and discharging, and the switches are configured as follows: q1, Q4, Q6, Q8 and Q10 are off, and Q2, Q3, Q5, Q7 and Q9 are on.

According to the switch array scheme of the battery module, the number of required switch devices is small (2 MOSFETs for each battery), and power leads from the galvanic pile to a battery management system circuit board are concise (only 8 power leads are needed for 5 batteries). The negative electrode of the battery B1 is used as the system ground of the battery module, and the batteries B4 and B5 are connected in series in a physical rigid manner on the premise of ensuring the dynamic connection/disconnection function, so that convenience is provided for the switch driving and system power supply design of the battery module.

The invention provides a battery module switch array driving circuit scheme. The switch arrays Q1/Q2, Q3/Q4, Q5/Q6, Q7/Q8 and Q9/Q10 are five groups of complementary switches, and two switches in each group of complementary switches cannot be conducted at the same time. The switch driving circuit is composed of a level transfer circuit, each group of complementary switches is controlled by two output signals of the controller, one signal directly controls one switch, and the other signal controls the other switch after being subjected to double input or not. Taking Q1/Q2 as an example, the switch driving circuit is shown in FIG. 4. The transistor QS1, QS2 and the resistors R1-R6 form a level shifting circuit which is directly controlled by an output signal Cntr1 of the charge and discharge control module. The transistors QS3 and QS4 and the resistors R7-R12 form another level shifting circuit, and output signals Cntr1 and Cntr2 of the charge and discharge control module are output and controlled through a double-input NOR gate N1. Cntr2 is normally set low and the output signal of nor gate N1 is inverted with respect to signal Cntr 1. When the Cntr1 is about to change state, the Cntr2 outputs high level, the nor gate N1 outputs low level, and then the Q2 is turned off, so that the situation that the complementary switches Q1/Q2 are turned on at the same time is avoided, and the dead zone control effect is achieved. For example, assuming that Cntr1 is initially low and Cntr2 is default low, QS2 turns off, QS1 turns off, and Q1 does not turn on; the nor gate N1 outputs a high level, which causes QS4 to turn on, QS3 turns on, Q2 turns on, and the battery B1 is in a main loop out state. If it is desired that B1 go into the on-main loop state, Cntr2 first outputs a high, nor gate N1 outputs a low, causing QS4 to turn off and QS3 to turn off, so Q2 is not turned on. The complementary switches Q1/Q2 are not conducted, and the battery B1 is in a high-resistance state towards the outside. After Q2 is sufficiently cut off, Cntr1 is set to be high level, QS2 is conducted, QS1 is conducted, Q1 is also conducted, the battery B1 is in a main loop connection state, Cntr2 restores to a default low level, and the state transition process of battery connection/disconnection is completed.

The invention provides a high-voltage signal generating circuit of a driving circuit, as shown in fig. 5. The capacitors C1 and C2, the diodes D3 and D4, and the charge pump controller U1 form a voltage doubler circuit. The anode of the battery B5 is selected as the input power supply, and the cathode of the battery B4 is used as the power ground DV-GND of the voltage doubling circuit, so that a high-voltage signal VDD _ H floating relative to the system ground of the battery module can be output. The charge pump controller U1 may be selected from the common 7660 series. Compared with other DCDC schemes, the voltage doubling circuit has the advantages of low static power consumption, no need of inductance, small occupied area and the like, and is very suitable for a switch array driving circuit.

As shown in fig. 6, the present invention provides a battery switch array scheme composed of P-type MOSFET devices, which can provide dynamic connection services for 5 batteries B11, B12, B13, B14, and B15; the switch array is composed of 10P-type MOSFET devices Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18, Q19, and Q20, wherein a drain of Q11 is connected to a cathode of a battery B11, a source of Q11 is connected to a drain of Q11, a source of Q11 is connected to an anode of the battery B11, a drain of Q11 is connected to a cathode of the battery B11, a source of Q11 is connected to a drain of the battery B11, a source of Q11 is connected to an anode of the battery B11, a source of Q11 is connected to a drain of Q11, a drain of Q11 is connected to a cathode of the battery B11, a drain of the battery B11 is connected to a cathode of the battery B11, a source of the battery B11, a drain of the battery B11 is connected to a drain of the battery B11, a source of the battery B11 is connected to a drain of the battery B11, a drain of the Q11 is connected to a drain of the battery B11, a drain of the battery B is connected to a drain of the Q11, a drain of the battery B11, a drain of the Q11, a drain of the battery B is connected to a drain of the battery B11, a drain of the battery B72, a drain of the battery B11, a drain of the Q11, a drain of the battery B72, a drain of the Q11, a drain of the battery B11, the source of Q19 is connected with the drain of Q17, the positive pole of battery B13 is connected with the negative pole of battery B14, the negative pole of the battery module is connected with the source of Q11, and the positive pole of the battery module is led out from the positive pole of battery B15.

From the view of a switch matrix topological structure, the N-type MOSFET scheme is similar to the P-type MOSFET scheme, namely, batteries in the galvanic pile are paired pairwise as much as possible, the positive electrode and the negative electrode are directly connected to form a physically connected rigid small module, and the left side and the right side of each row of 4 MOSFET devices realize the flexible connection function of each battery. For the condition that the number of batteries in the battery module is even, the small modules are directly connected in series to form the battery module. If the number of batteries in the battery module is odd, a minimum module comprising a single battery and two MOSFET devices is provided in addition to a certain number of the small modules. At this time, in order to be more favorable for the design of the matching power circuit, the following setting is preferred: for an N-type MOSFET device, a rigid small module is ensured to be positioned on the positive electrode side of the battery module, and for a P-type MOSFET device, a rigid small module is ensured to be positioned on the negative electrode side of the battery module, and then other small modules and a single battery are flexibly placed. It should be noted that fig. 5 and fig. 6 are only one kind of implementation examples of the present invention, and those skilled in the art can easily implement similar extended applications according to the related principles, for example, the battery module includes 2, 3, 4, 6, or 7 batteries.

The invention provides a switch array driving circuit scheme formed by P-type MOSFET devices. Taking Q11/Q12 as an example, the related circuit is shown in FIG. 7. The transistor QS21, QS22 and the resistors R21-R26 form a level shifting circuit which is directly controlled by an output signal Cntr3 of the battery charging and discharging balance scheduling module. The triodes QS23 and QS24 and the resistors R27-R32 form another level shifting circuit, and output control is carried out after output signals Cntr3 and Cntr4 of the battery charge-discharge balance scheduling module pass through a double-input NAND gate N2. Cntr4 is normally set high and the output signal of nand gate N2 is inverted with respect to Cntr 3. As an example, to illustrate the process of the battery state change, assuming that the initial state of Cntr3 is low, Cntr4 is high, and QS22 is turned on, then QS21 is turned on, and Q11 is turned on; the nor gate N2 outputs a high causing QS23 to turn off, in turn QS24 to turn off, Q22 to turn off, and battery B11 to switch in the main loop. If it is desired that B11 go out of the main loop, Cntr4 needs to be low first, and when Cntr3 goes high or low, nand gate N2 outputs high, which causes QS23 to turn off and QS24 to turn off, so Q12 is always off. Next, Cntr3 is turned high, QS22 is turned off, QS21 is turned off, Q11 is also turned off, and Q11/Q12 are not turned on, and thus, the dead zone state is achieved. Cntr4 then returns to the default high level, and nand gate N2 outputs a low level, which causes QS23 to turn on, and QS24 turns on, so Q12 also turns on. The battery B11 is in the state of being taken out of the main loop, and the state transition of battery connection/disconnection is completed.

The present invention provides a drive circuit negative power implementation as shown in fig. 8. The capacitors C11, C12, C13 and the charge pump controller U2 form a negative voltage circuit. The positive pole of the battery B12 is selected as the input power supply, and the negative pole of the battery B11 is used as the power ground NV-GND of the negative voltage circuit, so that a power supply VDD _ N with negative voltage relative to the system ground of the battery module can be output. The charge pump controller U2 may be in the conventional 7660 series. Compared with other DCDC circuits, the negative voltage circuit has the advantages of low static power consumption, no need of inductance, small occupied area and the like.

As shown in fig. 9, the method for controlling battery charging and discharging scheduling provided by the present invention specifically includes the following steps:

firstly, initializing parameters, determining the number M of batteries required to be accessed into a power main loop and the number F-M of vacant batteries of the battery module, and continuously monitoring battery state parameters in real time.

Selecting characteristic variables, judging the charge and discharge state of the battery module according to the current direction, and when the battery module discharges, making the variable R equal to the battery electric quantity, and when the battery charges, making the variable R equal to the charging quantity required by the battery (namely, the battery capacity minus the existing electric quantity).

Analysis of characteristic variables, and sequentially arranging R values of all F batteries of the battery module in descending order ₁ 、R ₂ …R _M …R _F . If with R _M As the center, the number of K and R are seen from the right _M Same (F-M is more than or equal to K is more than or equal to 0), namely R _M ＝R _M+1 ＝R _M+2 …＝R _M+K (ii) a When viewed from left, there are E number and R _M Same (M-1. gtoreq. E. gtoreq. 0), namely R _M ＝R _M－1 ＝R _M－2 …＝R _M－E . To meet the nominal voltage of the battery module, M batteries must be selected to access the main power loop. Therefore, sorting is carried out according to the R values, the first M batteries are selected to be connected into the main loop, and the next step is mainly used for processing a plurality of R values appearing in the R value sorting process _M The case of numerical values.

Judging and relevant operations according to the conditions, sequentially judging the following 4 conditions, and selecting the first met relevant operation to execute. Condition (a): when E, K takes the maximum value at the same time, i.e., E + K +1 ═ F, indicating that the battery is already in equilibrium, operation (a): sequentially selecting F-M batteries from the F batteries, placing the other batteries in a main loop for charging and discharging, and changing R every time R changes _M F, F-M)/(M W) (wherein W is the common multiple of (F-M) and F), selecting the batteries in turn again to carry out idle running until F batteries are fully charged or fully discharged after W/K switching; condition (b): when K is the minimum value 0, operation (b): the first M batteries (after being sorted according to R values) are selected to be charged and discharged, and other batteries are in an idle state until R is reached _M After the value is changed with R _M+1 The same is carried out until the same; condition (c): when (R) _M－E－1 －R _M+K+1 )/(R _M －R _M+K+1 ) And (c) when the ratio of E + K +1 to E +1 is not less than (E + K +1) or E is the maximum value M-1: sequentially selecting K batteries from the E + K +1 batteries, idle-placing the K batteries, connecting other batteries into the main loop for charging and discharging, and enabling the R value change amount to reach K (E + K +1) × (R) every time _M －R _M+K+1 ) And v (W + E +1)) (wherein W is the common multiple of K and (E + K +1)), the batteries are selected again in sequence to carry out idle running until the R values and R values of the E + K +1 batteries and R are switched for W/K times _M+K+1 The same is carried out until the two are identical; condition (d): when (R) _M－E－1 －R _M+K+1 )/(R _M －R _M+K+1 )<(E + K +1)/(E +1) or K is the maximum F-M, operation (d): k batteries are sequentially selected from the E + K +1 batteries and put in idle state, other batteries are connected into the main loop to be charged and discharged, and the R value of each battery changes (R value is changed) _M－E－1 －R _M ) (E + K +1)/W (wherein W is a common multiple of K and (E + K +1)),the batteries are selected again in sequence for idle running till the R values and R of the E + K +1 batteries are switched for W/K times _M－E－1 As well.

And fifthly, returning to the step 2 and circularly operating.

When the battery module is in a discharge state, the battery capacity is gradually reduced. When the battery module is in a charging state, the battery capacity is gradually increased, but the required charging amount is gradually decreased. Therefore, the electric quantity of the battery is directly applied during discharging, the charging quantity required by the battery is selected as the characteristic variable R during charging, the change rule is similar, and the subsequent unified treatment is facilitated. In the step (iv), the conditions a and b are specific examples of K, E in which the maximum value or the minimum value is taken, and need to be handled separately. Condition c means R _M Will reach the right cell R more quickly _M+K+1 Horizontal, and when the condition d is satisfied, R _M Will reach R more quickly _M-E-1 And (4) horizontal. Operation c is very similar to the implementation of operation d, except that the change in R value is different by a step size. The R value is related to the charging and discharging current and time, and can also be approximated by directly using the time for some applications with low precision requirements. And the four conditions in the step (IV) realize the comprehensive coverage of various distributions of R, K, E related numerical values. In addition, W in the step (iv) is a common multiple of K and (E + K +1), and the smaller the value of W, the fewer times of switching are required. Therefore, W can be the least common multiple, and the balancing speed is the fastest.

The battery equalization scheduling algorithm takes the Mth battery after the characteristic variables R are sequenced as the center, and through continuous battery switching optimization, the numerical values of more and more batteries are close to the center, and finally all batteries are completely the same, so that the equalization state is achieved.

The following describes an implementation process of the above battery discharge equalization scheduling algorithm by taking an example. Suppose that there are 6 lithium iron phosphate batteries in the pile of battery module, and battery module nominal voltage is 12V, therefore only need insert 4 batteries into the main loop that establishes ties can, 2 batteries can be idle take turns in another place. If the battery power is 10Ah, 9Ah, 8Ah, 7Ah, 6Ah, 5Ah in sequence, the battery discharge scheduling process is as shown in table 1, and after 13 times of battery switching, the power of all 6 batteries is discharged at the same time.

Table 1 example battery discharge scheduling procedure

Switching order	Vacant battery	Discharge capacity/Ah	R1	R2	R3	R4	R5	R6	Judgment of
										Initial state	R5、R6	1	10	9	8	7	6	5	Operation 2
After the 1 st handover	R4、R6	1	9	8	7	6	6	5	Operation 3
										After the 2 nd handover	R5、R6	1	8	7	6	6	5	5
After the 3 rd handover	R3、R4	1	7	6	5	5	5	5	Operation 4
										After the 4 th handover	R5、R6	1	6	5	5	5	4	4
After the 5 th handover	R2、R3	0.5	5	4	4	4	4	4	Operation 4
										After the 6 th handover	R4、R5	0.5	4.5	4	4	3.5	3.5	3.5
After 7 th handover	R2、R6	0.5	4	3.5	3.5	3.5	3.5	3
										After 8 th handover	R3、R4	0.5	3.5	3.5	3	3	3	3
After the 9 th handover	R5、R6	0.5	3	3	3	3	2.5	2.5
										After the 10 th handover	R1、R2	1.25	2.5	2.5	2.5	2.5	2.5	2.5	Operation 1
After 11 th switching	R3、R4	1.25	2.5	2.5	1.25	1.25	1.25	1.25
										After the 12 th handover	R5、R6	1.25	1.25	1.25	1.25	1.25	0	0
After the 13 th handover			0	0	0	0	0	0

As another example, the implementation process of the battery charging equalization scheduling algorithm is described. Suppose there are 6 lithium iron phosphate batteries in the battery module pile, and the nominal voltage of battery module is 12V, in order to satisfy the voltage specification of battery module, only need insert the series main loop 4 batteries can, but 2 batteries in addition can idle take turns and take rest. Assuming that the capacities of the batteries are all 15Ah, and the current electric quantities are 10Ah, 8Ah, 6Ah, and 5Ah, respectively, that is, the required charging quantities of the batteries are 5Ah, 7Ah, 9Ah, and 10Ah in sequence, and after 10 times of switching, all the batteries are fully charged, and the specific process is shown in table 2:

table 2 example battery charge scheduling procedure

Switching order	Vacant battery	Amount of charge/Ah	R1	R2	R3	R4	R5	R6	Judgment of
										Initial state	R4、R6	2	10	9	9	7	7	5	Operation 3
After the 1 st handover	R5、R6	2	8	7	7	7	5	5
										After the 2 nd handover	R2、R3	0.5	6	5	5	5	5	5	Operation 4
After the 3 rd handover	R4、R5	0.5	5.5	5	5	4.5	4.5	4.5
										After the 4 th handover	R2、R6	0.5	5	4.5	4.5	4.5	4.5	4
After the 5 th handover	R3、R4	0.5	4.5	4.5	4	4	4	4
										After the 6 th handover	R5、R6	0.5	4	4	4	4	3.5	3.5
After 7 th switching	R1、R2	1.75	3.5	3.5	3.5	3.5	3.5	3.5	Operation 1
										After 8 th handover	R3、R4	1.75	3.5	3.5	1.75	1.75	1.75	1.75
After the 9 th handover	R5、R6	1.75	1.75	1.75	1.75	1.75	0	0
										After the 10 th handover			0	0	0	0	0	0

As shown in fig. 10, the present invention provides a battery scheduling control method based on a heuristic algorithm, which has the outstanding advantages of small calculation amount, low measurement accuracy requirement, etc., and specifically includes the following steps:

initializing charge and discharge idle parameters, determining the number M of the batteries needing to be connected to the power main loop and the number F-M of the idle batteries, and continuously monitoring the state parameters of the batteries in real time.

Updating the idle parameters, and when charging, if a certain battery first reaches the over-charge protection voltage of the batteryIncreasing the charge vacancy parameter T of the battery _new ＝T _old + α, correspondingly decreasing the charge vacancy parameter T of the other battery _new ＝T _old - α/(F-1); when the battery is in discharge, if a certain battery first reaches the over-discharge protection voltage of the battery, the discharge vacancy parameter D of the battery is increased _new ＝D _old + beta, correspondingly reducing the discharge vacancy parameter D of the other cells _new ＝D _old －β/(F－1)。

Returning to the step

And (4) circulating operation.

The battery scheduling control algorithm only needs the battery voltage information which can be directly measured to carry out overcharge and overdischarge detection. Generally, voltage signals of the battery can change remarkably near overcharge and overdischarge, so that the requirement on the measurement accuracy of the battery voltage is low, and related hardware circuits are low in price. Step (ii) of

The initial value of the idle parameter T is related to the battery capacity and the current electric quantity, and can be set in a charging state and a discharging state respectively. Generally, the smaller the idle parameter setting, the higher the scheduling control accuracy, but the more frequent the battery switching will be, which may reduce the stability and reliability of the power supply system. Step (ii) of

The step length parameters alpha and beta in (1) can be set according to the idle parameters and the convergence speed requirement of the algorithm. The parameters D, T, α, β may be set to larger values for a good quality new battery. For the batteries with poor consistency in gradient utilization, the relevant parameters are set to be small values as much as possible.

The discharge equalization process implemented by the above algorithm is described as an example. Suppose that there are 5 lithium iron phosphate batteries B1, B2, B3, B4, B5 in the battery module stack, and the nominal voltage of battery module is 12V, and 4 batteries only need to be connected to the main loop in series in order to reach the voltage specification of battery module, so can make 1 battery spare in them. If the battery capacities are 10Ah, 9Ah, and 8Ah, respectively, and 100% full charge is performed before discharge is started, the initial values of the discharge idle state parameters of all the batteries are set to 1Ah, and the value of β is set to 0.2, the discharge capacity of the battery module is increased to 11.4Ah (close to the theoretical value of 11.75Ah) after 5 discharge cycles, and the idle state parameters of the batteries are updated to 0.7, 1.2, and 1.7, as shown in table 3. The battery scheduling procedure at 5 discharges is shown in tables 4-8.

TABLE 3 idle parameters and capacity variation during battery cycling discharge

TABLE 4 first discharge scheduling procedure

Switching order	Vacant battery	Discharge capacity/Ah	B1 electric quantity/Ah	B2 electric quantity/Ah	B3 electric quantity/Ah	B4 electric quantity/Ah	B5 electric quantity/Ah
								Initial state	B1	1	10	10	10	9	8
After the 1 st handover	B2		1	10	9	9	8									7
								After the 2 nd handover	B3	1	9	9	8	7	6
After the 3 rd switching	B4		1	8	8	8	6									5
								After the 4 th handover	B5	1	7	7	7	6	4
After the 5 th handover	B1		1	6	6	6	5									4
								After the 6 th handover	B2	1	6	5	5	4	3
After 7 th handover	B3		1	5	5	4	3									2
								After 8 th switching	B4	1	4	4	4	2	1
After the 9 th handover	B5		2	3	3	3	2									0
								After the 10 th handover		1	1	1	0	0

TABLE 5 2 nd discharge scheduling procedure

Switching order	Vacant battery	Discharge capacity/Ah	B1 electric quantity/Ah	B2 electric quantity/Ah	B3 electric quantity/Ah	B4 electric quantity/Ah	B5 electric quantity/Ah
								Initial state	B1	0.95	10	10	10	9	8
After the 1 st handover	B2	0.95	10	9.05	9.05	8.05	7.05
								After the 2 nd handover	B3	0.95	9.05	9.05	8.1	7.1	6.1
After the 3 rd handover	B4	0.95	8.1	8.1	8.1	6.15	5.15
								After the 4 th handover	B5	1.2	7.15	7.15	7.15	6.15	4.2
After the 5 th handover	B1	0.95	5.95	5.95	5.95	4.95	4.2
								After the 6 th handover	B2	0.95	5.95	5	5	4	3.25
After 7 th handover	B3	0.95	5	5	4.05	3.05	2.3
								After 8 th handover	B4	0.95	4.05	4.05	4.05	2.1	1.35
After the 9 th handover	B5	1.2	3.1	3.1	3.1	2.1	0.4
								After the 10 th handover	B1	0.4	1.9	1.9	1.9	0.9	0.4
After 11 th switching	B5	0.5	1.9	1.5	1.5	0.5	0
								After the 12 th handover			1.4	1.0	1.0	0	0

TABLE 6 3 rd discharge scheduling procedure

TABLE 7 4 th discharge scheduling procedure

Switching order	Vacant battery	Discharge capacity/Ah	B1 electric quantity/Ah	B2 electric quantity/Ah	B3 electric quantity/Ah	B4 electric quantity/Ah	B5 electric quantity/Ah
								Initial state	B1	0.8	10	10	10	9	8
After the 1 st handover	B2	0.8	10	9.2	9.2	8.2	7.2
								After the 2 nd handover	B3	0.8	9.2	9.2	8.4	7.4	6.4
After the 3 rd handover	B4	1.05	8.4	8.4	8.4	6.6	5.6
								After the 4 th handover	B5	1.55	7.35	7.35	7.35	6.6	4.55
After the 5 th handover	B1	0.8	5.8	5.8	5.8	5.05	4.55
								After the 6 th handover	B2	0.8	5.8	5	5	4.25	3.75
After 7 th switching	B3	0.8	5	5	4.2	3.45	2.95
								After 8 th switching	B4	1.05	4.2	4.2	4.2	2.65	2.15
After the 9 th handover	B5	1.55	3.15	3.15	3.15	2.65	1.1
								After the 10 th handover	B1	0.8	1.6	1.6	1.6	1.1	1.1
After 11 th switching	B2	0.3	1.6	0.8	0.8	0.3	0.3
								After the 12 th handover			1.3	0.8	0.5	0	0

TABLE 8 5 th discharge scheduling procedure

Switching order	Vacant battery	Discharge capacity/Ah	B1 electric quantity/Ah	B2 electric quantity/Ah	B3 electric quantity/Ah	B4 electric quantity/Ah	B5 electric quantity/Ah
								Initial state	B1	0.7	10	10	10	9	8
After the 1 st handover	B2	0.7	10	9.3	9.3	8.3	7.3
								After the 2 nd handover	B3	0.7	9.3	9.3	8.6	7.6	6.6
After the 3 rd handover	B4	1.2	8.6	8.6	8.6	6.9	5.9
								After the 4 th handover	B5	1.7	7.4	7.4	7.4	6.9	4.7
After the 5 th handover	B1	0.7	5.7	5.7	5.7	5.2	4.7
								After the 6 th handover	B2	0.7	5.7	5.0	5.0	4.5	4.0
After 7 th handover	B3	0.7	5.0	5.0	4.3	3.8	3.3
								After 8 th handover	B4	1.2	4.3	4.3	4.3	3.1	2.6
After the 9 th handover	B5	1.7	3.1	3.1	3.1	3.1	1.4
								After the 10 th handover	B1	0.7	1.4	1.4	1.4	1.4	1.4
After 11 th switching	B2	0.7	1.4	0.7	0.7	0.7	0.7
								After the 12 th handover			0.7	0.7	0	0	0

Claims

1. A battery system formed by connecting one battery module or a plurality of battery modules in series is characterized in that the battery module comprises F (F is more than or equal to 1) storage batteries, a switch array and driving circuit, and a battery state parameter detection and charge-discharge balance scheduling module; the switch array comprises 2 x F MOSFET devices, so that each storage battery can be independently connected into or disconnected from the power main loop; the battery state parameter detection module realizes the collection, processing and storage of battery state information; the battery state information comprises battery voltage, current, electric quantity and capacity; the charging and discharging balance scheduling module performs idle parameter calculation and battery time domain scheduling by using the battery state information obtained by the battery state parameter detection module to achieve the purpose of battery balance; the battery module is completely independent, and the battery charging and discharging protection and the balanced scheduling function are independently realized only by utilizing the self state information of the battery module.

2. The battery system of claim 1, wherein the cells in the stack are preferably paired in sets of two, the negative electrode of the first cell being connected to the positive electrode of the second cell; the first MOSFET, the second MOSFET and the first battery form a series loop, wherein the cathode of a parasitic diode of the first MOSFET is connected with the anode of the first battery, and the anode of a parasitic diode of the second MOSFET is connected with the cathode of the first battery; and the third MOSFET and the fourth MOSFET form a series loop with the second battery, wherein the anode of a parasitic diode of the third MOSFET device is connected with the cathode of the second battery, and the cathode of a parasitic diode of the fourth MOSFET device is connected with the anode of the second battery.

3. The battery system of claim 1, wherein the battery module stack comprises 5 batteries B1, B2, B3, B4 and B5; the battery module switch array comprises 10N-type MOSFET devices Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9 and Q10, wherein a drain of Q1 is connected to a positive electrode of a battery B1, a source of Q1 is connected to a drain of Q1, a source of Q1 is connected to a negative electrode of the battery B1, a drain of Q1 is connected to a source of Q1, a drain of Q1 is connected to a positive electrode of the battery B1, a source of Q1 is connected to a drain of Q1, a source of Q1 is connected to a negative electrode of the battery B1, a source of Q1 is connected to a drain of Q1, a drain of Q1 is connected to a positive electrode of the battery B1, a drain of Q1 is connected to a drain of the battery B1, a drain of Q1 is connected to a negative electrode of the battery B1, a drain of Q1 is connected to a drain of the battery B1, a drain of the Q1, and a drain of the Q1, a drain of the Q1 is connected to the Q1, a drain of the Q1 is connected to the Q1, a drain of the battery B1, a drain of the Q1 is connected to the Q1, a drain of the Q1 is connected to the Q1, a battery B1, a drain of the Q1 is connected to the Q1, a drain of the Q1 is connected to the Q1, a drain of the Q1, a battery B1, a drain of the Q1, a battery B1, a drain of the Q1, a drain of the, the source of Q5 is connected to the drain electrode of Q7, and battery B4's positive pole is connected to battery B5's negative pole, and the positive pole of battery module is connected to the source of Q9, and the negative pole of battery module is drawn forth from battery B1's negative pole.

4. The battery system of claim 3, wherein the switch array comprises five sets of complementary switches Q1/Q2, Q3/Q4, Q5/Q6, Q7/Q8, Q9/Q10; two switches in each group of complementary switches cannot be conducted simultaneously, two paths of output signals of the charge-discharge balance scheduling module are controlled by the level transfer circuit, one path of signals directly controls one switch, and the other path of signals controls the other switch after being subjected to double input or not-gating.

5. The battery system of claim 4, wherein the level shift circuit high voltage signal of the switch array driving circuit is derived from a voltage doubling circuit of the battery pack after the batteries B4 and B5 are connected in series.

6. The battery system of claim 1, wherein the battery module stack comprises 5 batteries B11, B12, B13, B14 and B15; the switch array comprises 10P-type MOSFET devices Q11, Q12, Q13, Q14, Q15, Q16, Q17, Q18, Q19 and Q20, wherein a drain of Q11 is connected to a cathode of a battery B11, a source of Q11 is connected to a drain of Q11, a source of Q11 is connected to an anode of the battery B11, a drain of Q11 is connected to a source of Q11, a drain of Q11 is connected to a cathode of the battery B11, a source of Q11 is connected to a drain of the battery B11, a source of Q11 is connected to a cathode of the battery B11, a drain of Q11 is connected to a drain of the Q11, a drain of Q11 is connected to a cathode of the battery B11, a drain of the battery Q11 is connected to a cathode of the battery B11, a source of the battery B11 is connected to a cathode of the battery B11, a drain of the battery B11, a source of the battery B11 is connected to a drain of the battery B11, a source of the battery B11, a drain of the Q11, a drain of the battery B11 is connected to a drain of the battery B11, a drain of the battery is connected to a drain of the battery B11, a source of the Q11, a drain of the Q11 is connected to a drain of the battery B11, a source of the Q11, a source of the battery B72 is connected to a drain of the battery B72, a drain of the battery B is connected to a drain of the battery B11, a drain of the battery B is connected to a drain of the battery B72, a drain of the Q11, a drain of the battery B72, a drain of the battery B11, a drain of the Q11, a drain of the battery B11, a drain of the Q11 is connected to a drain of the Q11, a drain of the battery B72, a source of the Q11 is connected to a drain of the Q11, a drain of the Q11 is connected to a drain of the Q11, a drain of the battery B72, a source of the battery B72, a drain of the battery B72 is connected to a drain of the Q11, a drain of the battery B72, a source of the Q11, a drain of the Q11 is connected to a, the source of Q19 is connected with the drain of Q17, the positive pole of battery B13 is connected with the negative pole of battery B14, the negative pole of the battery module is connected with the source of Q11, and the positive pole of the battery module is led out from the positive pole of battery B15.

7. The battery system of claim 6, wherein the switch array comprises five sets of complementary switches Q11/Q12, Q13/Q14, Q15/Q16, Q17/Q18, and Q19/Q20, two switches in each set of complementary switches cannot be turned on simultaneously, and two output signals of the charge-discharge equalization scheduling module are controlled by a level shift circuit, wherein one signal directly controls one switch, and the other signal controls the other switch after passing through a dual-input nand gate.

8. The battery system of claim 7, wherein the negative power supply of the level shift circuit of the switch array driving circuit is generated by a battery pack formed by connecting batteries B11 and B12 in series through a negative voltage circuit.

9. A charge-discharge balance scheduling method of a battery system for realizing the battery system or the battery module of any one of the claims 1 to 8,

the method comprises the following steps: initializing parameters, namely determining the number M of batteries needing to be accessed into a power main loop by a battery module, and continuously monitoring battery state parameters in real time; selecting a characteristic variable, judging the charge-discharge state of the battery module according to the current direction, and when the battery module discharges, making the variable R equal to the battery electric quantity, and when the battery charges, making the variable R equal to the charging quantity required by the battery; the R values of all F batteries of the battery module are sequentially R after being arranged in descending order ₁ 、R ₂ …R _M …R _F (ii) a The Mth battery after the characteristic variable R is sequenced is taken as the center, and the batteries are selected continuously and sequentially to be idle in turn, so that the numerical values R of more and more batteries are close to the center, and finally all the batteries are completely the same, and the balance state is achieved.

10. The method according to claim 9, characterized in that it comprises the steps of:

firstly, initializing parameters, wherein the number of batteries of a battery module, which need to be accessed into a power main loop, is M, and continuously monitoring battery state parameters in real time;

selecting a characteristic variable, judging the charge-discharge state of the battery module according to the current direction, and when the battery module discharges, making the variable R equal to the battery electric quantity, and when the battery charges, making the variable R equal to the charging quantity required by the battery (namely, the battery capacity minus the existing electric quantity);

analyzing characteristic variables, and sequentially arranging R values of all F batteries of the battery module in a descending order to be R ₁ 、R ₂ …R _M …R _F . If with R _M As the center, the number of K and R are seen from the right _M Same (F-M is more than or equal to K is more than or equal to 0), namely R _M ＝R _M+1 ＝R _M+2 …＝R _M+K (ii) a When looking to the left, there are E number and R _M Same (M-1. gtoreq. E. gtoreq.0), i.e., R _M ＝R _M-1 ＝R _M-2 …＝R _M-E ；

Condition judgment and correlation operation, the following 4 conditions are sequentially judged, the first encountered correlation operation meeting the condition is selected to be executed, and the condition (a): when E, K takes the maximum value at the same time, i.e., E + K +1 ═ F, indicating that the battery is already in equilibrium, operation (a): sequentially selecting F-M batteries from the F batteries for idle running, connecting other batteries to a main loop for charging and discharging, and when R changes RM x F (F-M)/(M x W) (wherein W is a common multiple of (F-M) and F), sequentially selecting the batteries again for idle running until the F batteries are fully charged or fully discharged after the W/K switching; condition (b): when K is the minimum value 0, operation (b): the first M batteries (after being sorted according to the R value) are selected to be charged and discharged, and other batteries enter an idle state until R _M After the value is changed with R _M+1 The same is carried out until the two are identical; condition (c): when (R) _M-E-1 -R _M+K+1 )/(R _M -R _M+K+1 ) Not less than (E + K +1)/(E +1) or when E is the maximum M-1, operating (c): sequentially selecting K batteries from the E + K +1 batteries, idle-placing the K batteries, connecting other batteries into the main loop for charging and discharging, and enabling the R value change amount to reach K (E + K +1) × (R) every time _M -R _M+K+1 ) And v (W + E +1)) (wherein W is the common multiple of K and (E + K +1)), the batteries are selected again in sequence to carry out idle running until the R values and R values of the E + K +1 batteries and R are switched for W/K times _M+K+1 The same is carried out until the two are identical; condition (d): when (R) _M-E-1 -R _M+K+1 )/(R _M -R _M+K+1 ) < (E + K +1)/(E +1) or K is the maximum F-M, operation (d): k batteries are sequentially selected from the E + K +1 batteries and put in idle state, other batteries are connected into the main loop to be charged and discharged, and the R value of each battery changes (R value is changed) _M-E-1 -R _M ) When the voltage of the battery is equal to or higher than the voltage of the battery, when the voltage of the battery is equal to or lower than the voltage of the battery, the battery is selected to be idle for rest again in sequence when the voltage of the battery is equal to or lower than the voltage of the battery, and the battery is switched to be in the idle state for W/K times _M-E-1 The same is carried out;

and fifthly, returning to the step II, and circularly operating.

11. A charge-discharge balance scheduling method for a battery system, which is used for implementing the battery system or module set in any one of claims 1 to 8, and is characterized by comprising the following steps:

initializing charge and discharge idle parameters, determining the number M of batteries needing to be connected into a power main loop and the number F-M of idle batteries, and continuously monitoring the state parameters of the batteries in real time;

except for the batteries in the overcharge or overdischarge protection state, all the batteries sequentially take turns by applying fixed idle parameters, and the on-off state of each battery is gradually updated;

updating the idle parameter, and increasing the charging idle parameter T of a certain battery if the battery reaches the over-charging protection voltage when in charging _new ＝T _old + α, correspondingly lowering the charge vacancy parameter T of the other battery _new ＝T _old - α/(F-1); when the battery is in discharge, if a certain battery first reaches the over-discharge protection voltage of the battery, the discharge vacancy parameter D of the battery is increased _new ＝D _old + beta, correspondingly reducing the discharge vacancy parameter D of the other cells _new ＝D _old -β/(F-1)；

Returning to the step

And (4) circulating operation.