CN115339331A

CN115339331A - Power battery charging and discharging main circuit

Info

Publication number: CN115339331A
Application number: CN202211043790.2A
Authority: CN
Inventors: 李志华
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-22
Filing date: 2022-08-22
Publication date: 2022-11-15

Abstract

The application provides a power battery matrix charges, main circuit that discharges belongs to battery charge and discharge technical field, and this circuit includes: the battery matrix comprises M multiplied by N single batteries and X power switch devices; the battery matrix is electrically connected with the power switch device and the lead in a grid structure shaped like a Chinese character tian; all the leads from the single battery to any electric node in the grid-shaped net structure are provided with at least one power switch device; the M multiplied by N single batteries can change the battery matrix into a battery pack formed by connecting a plurality of internal single batteries in series through the state conversion of the power switch device, and the battery packs can be connected in parallel or in series. According to the invention, each single battery is charged in sequence or more flexibly and sequentially charged in a multi-section manner through flexible and changeable realization of the main circuit of the battery matrix, so that the charging speed in a low-voltage and low-power manner is accelerated, and the performance, the service life and the safety of the battery matrix are improved.

Description

Main charging and discharging circuit of power battery

Technical Field

The invention belongs to the technical field of battery charging and discharging, and particularly relates to a main circuit technology for controlling charging and discharging of a power battery matrix.

Background

The charge speed of battery matrix, the security of whole life-span and group battery is the key factor of electric automobile development, present electric pile of filling can satisfy electric automobile's quick charge demand, because fill electric pile and can provide very big electric current in the course of the work, however, from the rapid development in electric motor car market and the development prospect of green energy, urban power supply network is difficult to satisfy most electric automobile and all adopts this kind of powerful electric pile of filling, present miniwatt charging mode adopts the low-current, the charging of low-voltage, this kind of mode charge speed is slow, can not satisfy people's demand to battery quick charge.

Although the performance of modern power battery matrixes is different, the structures of the modern power battery matrixes are basically consistent, and the battery matrixes are formed by connecting a plurality of single batteries in series into a battery pack and connecting the battery packs in parallel so as to improve the discharge voltage and current of the battery matrixes, and the fixedly connected battery matrixes also bring a plurality of technical problems which are difficult to solve: 1. when the single batteries are charged, the required charging voltage is not high, the charging current is not large, but when a plurality of single batteries are connected in series and in parallel to form a power battery pack which can drive the electric vehicle to run for more than 600 kilometers, the required direct current charging voltage is high, the current is large, if the charging time is required to be shortened, larger voltage and current are required, the requirement of quick charging cannot be met by a common commercial power interface and a small charger, and a high-power charging pile must be used; 2. after the performance of a certain single battery is seriously reduced, the single battery can seriously affect the overall performance of the battery pack; 3. serious failure or loss of a single battery can compromise the safety performance of the whole battery pack and even the electric equipment.

Disclosure of Invention

The invention changes the connection mode of the battery matrix through the conversion of the power switch device state in the main circuit of the battery matrix, and changes the charging mode of charging all the batteries simultaneously or charging in a multi-section sequential manner into charging each single battery in sequence or charging in a more flexible multi-section sequential manner by matching with an intelligent power supply system (the intelligent power supply system should comprise at least one path of program-controlled adjustable output and program-controlled multi-point trigger circuit, and the invention does not comprise software and hardware of the intelligent power supply system), so that the charging speed of the low-voltage and low-power mode is accelerated, the safety of the battery is improved, and the problems that the performance, the service life and the safety of the whole battery matrix are influenced by the faults of partial single batteries are simultaneously alleviated.

In order to achieve the above object, the invention proposes a scheme 1: a controllable cell matrix main circuit in the shape of a Chinese character 'mu', the circuit comprising: the battery pack is electrically connected with the lead through the power switch device and the lead in a herringbone structure, and all the connecting leads from the single batteries to any electrical node in the herringbone structure are provided with at least one power switch device; n is an integer greater than 0, and X is an integer greater than 0.

In order to achieve the above purpose, the invention proposes a scheme 2 that: a controllable grid-shaped main circuit of a reticulated battery matrix, the circuit comprising: the battery matrix comprises M multiplied by N single batteries and X power switch devices, the battery matrix is in a grid-shaped net structure through the power switch devices and the wires in electrical connection, at least one power switch device is arranged on all wires from the single batteries to any electrical node in the grid-shaped net structure, M is an integer larger than 0, N is an integer larger than 0, and X is an integer larger than 0, the M multiplied by N single batteries can be regarded as M groups of batteries, each group of batteries comprises N single batteries, the N single batteries in each group can form a series circuit through a closed loop of the power switch, and each group of batteries can form a parallel circuit.

In order to achieve the above object and provide a more flexible circuit connection method, the invention proposes the following scheme 3: a controllable balanced grid-like mesh battery matrix main circuit, the circuit comprising: the battery pack is in a grid-shaped net structure on electrical connection through the power switch devices and the wires, at least one power switch device is arranged on all wires from the single batteries to any electrical node in the grid-shaped net structure, M is an integer larger than 0, N is an integer larger than 0, X is an integer larger than 0, and T is an integer larger than or equal to 0, the M multiplied by N single batteries can be regarded as M groups of batteries, each group of batteries comprises N single batteries, the N single batteries in each group can form a series circuit through a closed loop of the power switch, a plurality of adjustable resistors are connected in series in a sequentially connected circuit of each group of batteries, the serially connected adjustable resistors can form a series circuit with the sequentially connected battery packs, and each battery pack can form a parallel circuit.

The grid-shaped structure in the above scheme 1, scheme 2 and scheme 3 means that the circuit presents the grid shape of the Chinese character on the electrical connection diagram, and the grid-shaped mesh battery pack circuit means that the circuit presents the mesh structure of the Chinese character grid shape on the local electrical connection diagram.

In the

above solutions

1, 2 and 3, as shown in fig. 1, 2 and 3, a switch may be respectively disposed at electrically adjacent positions on two sides of each single battery as required, and as shown in fig. 1, B2, a switch S21 and S22 are respectively disposed on two sides of the battery; it is also possible to provide only one switch S21 at a position electrically adjacent to one side of each cell, so as to disconnect the cells in the branch circuit from the main circuit.

In the above schemes 2 and 3, the M × N single battery matrixes included in the battery matrix may also be formed by connecting less than N batteries in series to form a battery pack, the number of the battery packs is less than M × N, and the battery packs may be connected in parallel or in series.

In the using process of the scheme 1, the scheme 2 and the scheme 3, the appointed switch can be switched off or switched on through a trigger control circuit of a power switch device in an intelligent power supply system according to needs, so that the single batteries in the battery matrix can be connected into a needed mode and then connected to a power supply for charging or connected to an electric appliance for discharging.

The main circuit for charging and discharging the power battery can be used as a main circuit for charging and discharging batteries for various other purposes.

The charging process of the scheme 1 provided by the invention mainly comprises the following steps:

1. before charging, all high-power switches are ensured to be in an off state.

2. And respectively detecting the voltage and the resistance of all the N single batteries, and determining the single batteries to be charged and the number of the single batteries to be charged.

3. And selecting a proper switch to be closed according to the magnitude of the output voltage which can be provided by the charging power supply, and sequentially charging or serially charging the determined i single batteries.

4. The state of the battery is detected in the charging process, the current charging of a certain battery is completed, the battery is disconnected from the charging circuit through the power switch, the bypass switch of the branch where the battery is located is closed according to needs, and then the other single batteries needing to be charged are charged in series or sequentially.

5. And repeating the steps 3-4 until all the batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process of the scheme 1 provided by the invention mainly comprises the following steps:

1. all switches are ensured to be in the off state before discharging.

2. And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the N single batteries, and recording the current state data of the batteries.

3. According to the requirements of electric equipment, i single batteries are determined to be selected for series connection and then discharged.

The charging process of the scheme 2 provided by the invention mainly comprises the following steps:

1. all high power switches are ensured to be in an off state.

2. And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the MXN single batteries, and determining the i single batteries to be charged.

3. According to the voltage and current provided by the charging power supply and the position of the i batteries, selecting a proper switch to be closed, and sequentially charging or charging in series-parallel connection the determined i single batteries.

4. And detecting the state of the battery in the charging process, and if the charging of the battery is finished, disconnecting the battery from the charging circuit through the power switch and connecting other single batteries needing to be charged to perform series-parallel charging or sequential charging.

5. And repeating the steps 3-4 until all the batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process of scheme 2 proposed by the present invention mainly comprises the following steps:

1. all switches are ensured to be in the off state before discharging.

2. And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the M multiplied by N single batteries, and recording the current state data of the batteries.

3. And determining to select i single batteries for series connection and parallel connection and then discharging according to the requirements of the electric equipment.

In the above step, i is an integer of 0 or more.

The charging process of scheme 3 provided by the invention mainly comprises the following steps:

1. all high power switches are ensured to be in an off state before charging.

3. And according to the voltage and current provided by the charging power supply and the position of the i batteries, selecting a proper switch to be closed, and sequentially charging or charging in series-parallel connection the determined i single batteries.

5. If the resistances of the battery pack branches connected in parallel are different, the adjustable resistance value is connected into the required branch in series according to the requirement, so that the resistances of the branches connected in parallel are similar or identical.

6. And repeating the steps 3-5 until all batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process of scheme 3 proposed by the present invention mainly comprises the following steps:

1. all switches are ensured to be in an open state before discharging.

3. According to the requirements of electric equipment, i single batteries are determined to be selected for series connection and parallel connection and then discharged.

4. If the terminal voltages of a plurality of battery packs formed by connecting the i single batteries are different and the battery packs are required to be connected in parallel, the adjustable resistor is connected in series to the battery pack with the higher terminal voltage through the control of the power switch, the resistance value is adjusted, the output voltages of the parallel branches are the same, and then the battery pack branches are connected in parallel.

In the above step, i is an integer of 0 or more.

Drawings

Fig. 1 is a schematic diagram of a main circuit of a controllable parallel-line battery pack provided in claim 1, where switches in the diagram all represent controllable high-power switching devices, where an element identified by a letter B is a single battery, or a series combination of a plurality of single batteries, and an element identified by a letter S or a letter K is a controllable power switching device.

Fig. 2 is a schematic diagram of a main circuit of a controllable grid-shaped battery pack provided in technical scheme 2 of the present application, where switches in the diagram are all controllable power switches, where an element identified by a letter B is a single battery, or a series combination of a plurality of single batteries, and an element identified by a letter S or a letter K is a controllable power switch.

Fig. 3 is a schematic diagram of a main circuit of a controllable balanced grid-shaped battery pack according to claim 3. The switches in the figure are all controllable power switch devices, wherein the element marked by the beginning of the letter B is a single battery, or a series combination of a plurality of single batteries, the element marked by the beginning of the letter S or the letter K is a controllable power switch device, and the element marked by the beginning of the letter R is an adjustable resistor.

Fig. 4 is a specific embodiment of the controllable main circuit of the parallel-grid-shaped battery pack provided in claim 1 of the present application, where switches in the diagram all represent controllable high-power switching devices, where an element identified by a letter B is a single battery, or a series combination of multiple single batteries, and an element identified by a letter S or a letter K is a controllable power switching device.

Fig. 5 is a specific embodiment of a main circuit of a controllable grid-shaped battery pack according to claim 2, where switches in the diagram are all controllable power switches, where an element identified by a letter B is a single battery, or a series combination of a plurality of single batteries, and an element identified by a letter S or a letter K is a controllable power switch.

Fig. 6 is a specific embodiment of a main circuit of a controllable balanced grid-shaped mesh battery pack according to claim 2. The switches in the figure are all controllable power switch devices, wherein the element marked by the beginning of the letter B is a single battery, or a series combination of a plurality of single batteries, the element marked by the beginning of the letter S or the letter K is a controllable power switch device, the element marked by the beginning of the letter R is an adjustable resistor, or a series combination of a plurality of adjustable resistors.

Detailed Description

Reference will now be made in detail to the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout, and which are illustrated in the accompanying drawings and described below for the purpose of explanation, and not limitation of the present application.

In the specific embodiment of scheme 1, in scheme 1, N =4,x =15 is taken, that is, a main circuit of a battery pack includes 4 single batteries and 15 switching devices to form a main charging and discharging circuit of the battery pack, as shown in fig. 4, where B1, B2, B3, and B4 are four single batteries, respectively, S11, S12, S21, S22, S31, S32, S41, S42, K1, K2, K3, K4, K11, K21, K31, and K41 are controllable power switches, during charging, all power switches are turned off first, and if all batteries are intact and a charging power supply voltage can meet the charging requirement of all batteries, switches with a letter beginning with K are all turned off, switches with a letter beginning with S are all turned on, and switches with a letter beginning with S are all turned on to form a charging circuit in which four batteries are connected in series with each other; if the voltage of a charging power supply can only charge two single batteries in series at the same time, connecting a certain two batteries in series to the charging power supply through a power switch, disconnecting all the power switches after the two batteries are charged, then closing some switches to connect other two batteries in series and to the charging power supply, sequentially charging every two batteries in series, for example, S11, S12, S21, S22, K21, K3 and K4 are closed, other power switches are kept disconnected, firstly charging B1 and B2 in series, after the charging of B1 and B2 is completed, all the switches are disconnected, then closing K1, K2, K21, S31, S32, S41 and S42, and other switches are kept in an off state, and charging B3 and B4; if the charging voltage can only charge one single battery, controlling the power switch to connect one battery to the charging power supply, disconnecting other batteries from the charging power supply, and after one battery is charged, disconnecting the charged battery by controlling the power switch and then connecting another battery to be charged to sequentially charge each single battery of the battery pack; if some batteries are damaged, for example, B2 is damaged and the batteries cannot be used continuously, the two switches S21 and S22 are opened, other corresponding switches starting with the letter S are closed, K11, K2 and K21 are also closed, other power switches are kept in an opened state, three single batteries B1, B3 and B4 can still be connected in series, and a charging power supply charges the three single batteries connected in series; the discharging process needs to select the battery and the connection mode thereof according to the requirement of the load, and is implemented by controlling the state transition of the power switch, and the principle is as described in the steps mainly included in the charging process and the discharging process of the above scheme 1, which is not described herein again.

In the embodiment of scheme 2, taking M =3, n =4, x =44, that is, a specific form of the main charging and discharging circuit of the battery matrix described in scheme 2, the circuit includes 12 single batteries and 44 switching devices, and generally can constitute a main charging and discharging circuit of 3 groups of batteries, as shown in fig. 5, the connection of the battery matrix may be B11, B12, B13, and B14 as a first group, B21, B22, B23, and B24 as a second group, and B31, B32, B33, and B34 as a third group, so as to form a battery matrix of three battery packs, if all the batteries and the charging power supply voltage and current can satisfy the charging requirements of all the batteries, the switches of the initial letter K are all opened, the switches of the initial letter S are all closed, the batteries of each group are connected in series, the batteries of each group are connected in parallel, and the three battery packs are simultaneously connected to the charging power supply; according to the power of the charging power supply, each battery pack can also be controlled to be connected in sequence, so that each battery pack is charged in sequence; the battery pack may not be the above-mentioned three specific groups of batteries, and may also control a power switch as needed, and select any single battery that can be connected in series, for example, select B11, B22, B33, B34 to form a battery pack; the connection modes between the batteries are many and are difficult to exhaust. When the battery is damaged, for example, the B22 battery is damaged and cannot be used continuously, S221 and S222 are disconnected, so that the circuit where the B22 battery is located is disconnected from other circuits, the current no longer flows through the branch, the B22 battery no longer participates in the charging and discharging processes, according to the charging or discharging requirement, K112, K12 and K122 can be closed, K112, K12, K122, K211, K22 and K221 can also be closed to realize the bypass of the branch where the B22 is located, and according to the requirement, the bypass can not be provided for the branch where the B22 is located; in the subsequent charging and discharging processes, the main circuit and the control circuit cooperate to realize charging or discharging according to needs, the battery and the connection mode thereof selected in the specific charging process are determined by the voltage and the current provided by the power supply, and the discharging process needs to select the battery and the connection mode thereof according to the needs of the load, and is realized by controlling the state switching of the power switch, which is mainly the steps included in the charging process and the discharging process of the scheme 2 as described above, and the details are not repeated here.

In the specific embodiment of scheme 3, taking that M =3, n =4, x =56, t =3 is an implementation manner of the main circuit described in scheme 3, the battery matrix includes 12 single batteries, 56 switching devices, 3 adjustable resistors, and during charging and discharging, the connection manner of the battery pack is substantially the same as that of scheme 2, and generally constitutes a charging and discharging circuit of 3 groups of batteries, as shown in fig. 6, where B11, B12, B13, and B14 are a first group, B21, B22, B23, and B24 are a second group, B31, B32, B33, and B34 are a third group, and a battery matrix of three battery packs is formed, and all power switching devices are in an off state: if all batteries are intact, the voltage and current of a charging power supply can meet the charging requirements of all batteries, K101, K102, K201, K202 and K10 are closed, other switches with K beginning letters are all opened, S101, S102, S201, S202, S301 and S301 are opened, other switches with S beginning letters are all closed, three groups of batteries are connected in series, all groups are connected in parallel, the three groups of batteries are simultaneously connected to the charging power supply, and an adjustable resistor is not connected to a charging circuit; if one battery in a certain group is damaged and the battery is required to be charged as soon as possible, the damaged battery can be disconnected and bypassed, an adjustable resistor is connected in series in a series circuit of the battery pack to realize the equal resistance of each parallel branch so as to realize quick charging and reduce circulating current, for example, in the three groups of connected battery packs, B22 is damaged, S221, S222, S101, S102, S301 and S302 are disconnected, switches marked by the beginning of other S are closed, K10, K101, K211, K221, K22, K202 and K20 are closed, switches marked by the beginning of K are opened, B22 is disconnected from the second group of battery packs and bypassed and then connected into an adjustable resistor R2, and all batteries are charged at the same time at the similar speed; during the discharging process, the battery and the connection mode thereof can be selected through the state conversion of the switch according to the requirement of the load to realize the power supply for the load; if the batteries are found to be damaged in the discharge preparation, for example, the B22 battery is damaged and cannot be used continuously, the two switches S221 and S222 are opened, so that the circuit where the B22 battery is located is disconnected from other circuits, the current does not flow through the branch, the B22 battery does not participate in the charging and discharging processes, in the subsequent charging and discharging processes, K112, K12 and K122 can be closed according to needs, or K112, K12, K122, K211, K22 and K221 can be closed to realize the bypass of the branch where the B22 is located, so that the batteries connected in series with the B22 can still be connected in series, if the terminal voltages of the branches connected in parallel are different, the branches connected in series can be connected into the adjustable resistor again to be adjusted appropriately, and after the terminal voltages of the battery pack branches connected in parallel are close to or the same, the battery pack branches connected in series and having the adjustable resistor can be connected in parallel to form a battery matrix for supplying power to the outside; after a plurality of battery packs are formed, if the battery packs are connected in parallel, different resistances of parallel branches can be caused by different battery numbers of the battery packs connected in parallel in the charging process, so that the charging speeds of the battery packs charged simultaneously are different, and if the speeds of the battery packs are the same, an adjustable resistance can be connected in series to the branch with the small resistance in the charging process; in the discharging process, the terminal voltages of all parallel battery packs are different, so that circulation current appears among the battery packs, at the moment, the terminal voltages of all serial branches are close to or the same by connecting adjustable resistors in series into the battery packs with high terminal voltages, so that the circulation current is reduced or even eliminated, and all the battery packs and the adjustable resistors form a controllable balanced grid-shaped battery matrix main circuit to supply power outwards; the main circuit is matched with the control circuit to realize charging or discharging, and the circulating current is small; specifically, in the charging process, the state of the power switch in the main circuit is determined by the voltage and current provided by the power supply, while in the discharging process, the battery, the adjustable resistor and the connection mode thereof need to be selected according to the needs of the load, and the selection is realized by controlling the state conversion of the power switch, so that the mode is very flexible.

Advantageous effects

1. The main circuit for charging and discharging the power battery can be matched with a corresponding control circuit according to the condition of a power supply to provide large-range voltage and current charging: when the power supply voltage is low, a small number of batteries are selected to be connected in series for charging, when the power supply voltage is high, a large number of batteries can be selected to be connected in series for charging, when the power supply current is small, a small number of batteries are selected to be connected in parallel for charging, when the power supply current is large, a large number of batteries are selected to be connected in parallel for charging, and under the conditions of low voltage and low current, each single battery can be charged in sequence, so that the power battery can be charged by using a low-power supply, for example, the power battery is charged by using a solar battery in sequence.

2. The main circuit for charging and discharging the power battery can prolong the service life of the battery pack, and can cut off the battery from the charging and discharging circuit by controlling the on-off of the high-power switch if the performance of the battery is reduced or damaged through detection, so that the performance reduction and damage of the single battery can not seriously affect the performance of the whole battery pack.

3. The main circuit for charging and discharging the power battery can improve the safety performance of a battery pack power supply object, and when the battery is seriously impacted and has serious faults or risks such as explosion and the like, the battery can be cut off from the charging and discharging circuit by controlling the on-off of the high-power switch, so that the discharging current of the battery pack does not flow through the faulty battery any more when the single battery has serious faults or has explosion risks, the range and the degree of the faults or the risks are limited, and the safety of the battery pack power supply object is improved.

4. The main circuit for charging and discharging the power battery can be matched with an intelligent power supply, so that efficient accurate charging is provided for different connection modes of different numbers of single batteries, for example, after conventional charging is completed, only a small number of single batteries are left to be charged, the output voltage and current of the intelligent power supply can be adjusted through proper connection matching according to the number of the batteries to be charged, and efficient accurate charging is realized.

5. The main circuit for charging and discharging the power battery provided by the invention can be matched with a proper control circuit to supply power for various electric equipment with different voltage and current requirements.

The batteries described in this specification each represent a secondary battery capable of being repeatedly charged and discharged; the single battery in the specification represents a single battery, and can also be an integral battery formed by connecting a plurality of single batteries in series; the battery pack described in this specification indicates a plurality of batteries connected in series with each other; the high-power switch device described in this specification may be a power field effect transistor (power MOSFET) or an Insulated Gate Bipolar Transistor (IGBT), and may also be a controllable power device capable of switching on and off a circuit, such as an Integrated Gate Commutated Thyristor (IGCT); the switch or the power switch described in the present specification represents a controllable power switch device.

Claims

1. A controllable cell matrix main circuit in the shape of a Chinese character 'mu', the circuit comprising: the battery pack is in a structure in a shape like a Chinese character 'mu' through the power switch device and the lead, and all the connecting leads from the single batteries to any electrical node in the structure in the shape like the Chinese character 'mu' are provided with at least one power switch device; n is an integer greater than 0, and X is an integer greater than 0.

2. A controllable grid-shaped main circuit of a reticulated battery matrix, the circuit comprising: the battery matrix comprises M multiplied by N single batteries and X power switch devices; the battery matrix is electrically connected with the power switch device and the lead in a grid-shaped net structure; all the leads from the single battery to any electrical node in the grid-shaped mesh structure are provided with at least one power switch device; m is an integer greater than 0, N is an integer greater than 0, and X is an integer greater than 0; the M × N single batteries may be regarded as M groups of batteries, each group of batteries includes N single batteries, the N single batteries in each group may form a series circuit through a closed loop of the power switch, and each group of batteries may form a parallel circuit.

3. A controllable balanced grid-like mesh battery matrix main circuit, the circuit comprising: the battery matrix comprises M multiplied by N single batteries, X power switch devices and T adjustable resistors; the battery pack is electrically connected with the power switch device and the lead in a grid-shaped net structure; at least one power switch device is arranged on all the leads from the single battery to any electric node in the grid-shaped net structure; m is an integer greater than 0, N is an integer greater than 0, X is an integer greater than 0, and T is an integer greater than or equal to 0; the M × N single batteries may be regarded as M groups of batteries, each group of batteries includes N single batteries, the N single batteries in each group may form a series circuit through a closed loop of a power switch, a plurality of adjustable resistors are connected in series in a sequentially connected line of each group of batteries, the connected adjustable resistors may form a series circuit with the sequentially connected battery groups, and each battery group may form a parallel circuit.

4. A circuit according to claim 1, 2 or 3, wherein only one switch is provided in electrical proximity to one side of each cell to disconnect the cells in the branch from the main circuit.

5. The circuit according to claim 2 or 3, wherein M x N single cells contained in the cell matrix, and less than N cells are connected in series to form a cell group, the number of the cell group is less than M x N, and the cell groups can be connected in parallel or in series.

6. A method of using a main circuit as claimed in claim 1, characterized in that the method of use is:

the charging process mainly comprises the following steps:

(1) Before charging, all high-power switches are ensured to be in an off state.

(2) And respectively detecting the voltage and the resistance of all the N single batteries, and determining the single batteries to be charged and the number of the single batteries to be charged.

(3) And selecting a proper switch to be closed according to the magnitude of the output voltage which can be provided by the charging power supply, and sequentially charging or serially charging the determined i single batteries.

(4) The state of the battery is detected in the charging process, the current charging of a certain battery is completed, the battery is disconnected from the charging circuit through the power switch, the bypass switch of the branch where the battery is located is closed according to needs, and then the other single batteries needing to be charged are charged in series or in sequence.

(5) And (4) repeating the steps (3) to (4) until all the batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process mainly comprises the following steps:

(1) All switches are ensured to be in the off state before discharging.

(2) And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the N single batteries, and recording the current state data of the batteries.

(3) According to the requirements of electric equipment, i single batteries are determined to be selected for series connection and then discharged.

In the above step, i is an integer of 0 or more.

7. A method of using a main circuit as claimed in claim 2, characterized in that the method of use is:

the charging process mainly comprises the following steps:

(1) Ensuring that all high power switches are in an off state.

(2) And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the MXN single batteries, and determining the i single batteries to be charged.

(3) And according to the voltage and current provided by the charging power supply and the position of the i batteries, selecting a proper switch to be closed, and sequentially charging or charging in series-parallel connection the determined i single batteries.

(4) And detecting the state of the battery in the charging process, and if the charging of the battery is finished, disconnecting the battery from the charging circuit through the power switch and connecting other single batteries needing to be charged to perform series-parallel charging or sequential charging.

(5) And (5) repeating the steps (3) to (4) until all batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process mainly comprises the following steps:

(1) All switches are ensured to be in the off state before discharging.

(2) And controlling the corresponding power switch devices to be closed, respectively detecting the voltage and the resistance of all the M multiplied by N single batteries, and recording the current state data of the batteries.

(3) And determining to select i single batteries for series connection and parallel connection and then discharging according to the requirements of the electric equipment.

In the above step, i is an integer of 0 or more.

8. A method of using a main circuit as claimed in claim 3, characterized in that the method of use is:

the charging process mainly comprises the following steps:

(1) Before charging, all high-power switches are ensured to be in an off state.

(5) If the resistances of the battery pack branches connected in parallel are different, the adjustable resistance value is connected into the required branch in series according to the requirement, so that the resistances of the branches connected in parallel are similar or identical.

(6) And (5) repeating the steps (3) to (5) until all the batteries are charged.

In the above step, i is an integer of 0 or more.

The discharge process mainly comprises the following steps:

(1) All switches are ensured to be in the off state before discharging.

(4) If the terminal voltages of a plurality of battery packs formed by connecting the i single batteries are different and the battery packs are required to be connected in parallel, the adjustable resistor is connected in series to the battery pack with the higher terminal voltage through the control of the power switch, the resistance value is adjusted, the output voltages of the parallel branches are the same, and then the battery pack branches are connected in parallel.

In the above step, i is an integer of 0 or more.