CN114256931A

CN114256931A - Battery balancing device

Info

Publication number: CN114256931A
Application number: CN202111605661.3A
Authority: CN
Inventors: 陈文芗
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-12-25
Filing date: 2021-12-25
Publication date: 2022-03-29

Abstract

The invention discloses a battery balancing device, which relates to the field of battery application in power electronic technology, and comprises: the system comprises a battery pack, an auxiliary charging unit, a first router, a second router and a control unit; an active (active) battery equalization management technique is proposed: and setting a first router and a second router, and using the first router and the second router in combination with the battery pack. By controlling the state transition of the first and second routers, an auxiliary charging loop can be conveniently formed between the auxiliary charging unit and the single battery with lower voltage in the battery pack, so as to provide auxiliary charging current for the auxiliary charging unit. The first router and the second router are independent. When the device is applied, the first router independently leads the output end of the auxiliary charging unit to the cathode of the single battery with lower voltage, and the second router independently leads the output end of the auxiliary charging unit to the anode of the single battery with lower voltage. The control strategy can effectively reduce the difficulty of the control strategy of the battery pack balance management system.

Description

Battery balancing device

Technical Field

The embodiment of the invention relates to a power electronic technology, in particular to a battery balancing device in the field of battery application.

Background

Batteries, such as power batteries of electric vehicles, need to be charged or discharged during use, and therefore management techniques of batteries during charging or discharging are important practical techniques. Since the batteries produced by the battery factory are all single batteries (cells) with relatively low voltage, the single batteries need to be connected in series (grouped) to reach the used voltage level. Due to the difference between each single battery, a short plate effect occurs after the single batteries are connected in series, namely, the single battery with the worst performance influences the performance of the grouped batteries. In practical applications, how to solve the short plate effect of the grouped batteries is a difficult problem for battery engineers.

The main method for solving the short plate effect of the grouped batteries is to perform balance management on the battery pack, namely to perform balance processing on each single battery in the use process of the batteries. The equalization management method includes two types of passive equalization and active equalization. The passive equalization is also called passive equalization, namely, the discharge processing is carried out on the single batteries with high energy, the specific technical action is to find the single batteries with high energy, and the parallel resistors consume part of the energy, so that the purpose of energy balance among the batteries is achieved. Passive equalization management is not a problem in principle, but is clearly not a good solution because it consumes valuable energy from the battery and the energy consumed becomes heat, increasing the difficulty of thermal management of the battery pack. The principle of active equalization is that a single channel for auxiliary charging is established for a single battery with less energy by using a power electronic technology, and the energy of the single battery is additionally increased to achieve the purpose of energy balance among batteries. Active equalization is a main technical direction of equalization management of battery packs at present due to its outstanding advantages.

However, the number of the single batteries in the battery pack is large, and it is difficult to establish a separate auxiliary charging channel among the plurality of single batteries connected in series. Currently, active equalization topologies mainly include centralized equalization topology and distributed equalization topology (Chenyang, Liudafang, Yangshi, etc. active equalization topology overview of series battery, Power Collection, 2013(5): 9). However, no matter which balanced topology structure is adopted, a large number of switching devices or energy storage devices (inductors, capacitors and the like) are needed to establish independent auxiliary charging channels among all the single detection devices, and the circuit structure is complex. In addition, because the direct current potentials of the single batteries connected in series are different, the switching devices at different positions need mutually isolated driving circuits, and the system control is very difficult. The problems currently encountered by active equalization management greatly affect the application of the active equalization management to battery equalization management, so that numerous scholars and engineers are seeking better topology and control methods of battery equalization management systems.

Disclosure of Invention

The invention provides a battery equalization management device based on a series switch structure, which aims to simplify the structure of a battery active equalization device and reduce the control difficulty of the battery active equalization device.

The invention provides a battery equalization management device, comprising: a battery pack;

an auxiliary charging unit;

a first router;

a second router;

a control unit;

wherein:

the battery pack comprises n single batteries E1, E2, E3 … …, En-1 and En, the number of the n single batteries is not less than 1 and is connected with the single batteries in a series connection mode, and a positive terminal BAT + of the battery pack is connected with a + end and a negative terminal BAT + of a main charger or an electric appliance and is connected with a-end of the main charger or the electric appliance;

the auxiliary charging unit is connected with the first router and the second router and is used for carrying out auxiliary charging current on the selected at least 1 single battery;

the first router and the second router comprise n +1 ports and are connected with the battery pack and the control unit;

the connection of the A0 port, the A1 port, the A2 port, the A3 port and the An-1 port … … An port of the first router is as follows: the port A0 is connected with the output end of the auxiliary charging unit, the port A1 is connected with the negative electrode of a single battery E1 in the battery pack, the port A2 is connected with the negative electrode of a single battery E2, other ports are connected in the same way, and the port An is connected with the negative electrode of a single battery En;

the connection of the B0 port, the B1 port, the B2 port, the B3 port … … Bn-1 port and the Bn port of the second router is as follows: the port B0 is connected with the + output end of the auxiliary charging unit, the port B1 is connected with the positive electrode of a single battery E1 in the battery pack, the port B2 is connected with the positive electrode of a single battery E2, other ports are connected in the same way, and the port Bn is connected with the positive electrode of a single battery En;

the control unit controls the working state of the first router and the working state of the second router according to the voltage condition of the selected single battery;

if the first router is in a working state M11, the A0 port of the first router is connected with the A1 port;

if the first router is in a working state M12, the A0 port of the first router is connected with the A2 port;

and so on;

if the first router is in a working state M1n, the port A0 of the first router is connected with the port An;

if the first router is in a working state M1n +1, the port A0 of the first router is disconnected with all ports;

if the second router is in a working state M21, connecting the port B0 of the second router with the port B1;

if the second router is in a working state M22, connecting the port B0 of the second router with the port B2;

and so on;

if the second router is in a working state M2n, connecting a port B0 in the second router with a port Bn;

if the second router is in the working state M2n +1, the port of the second router B0 is disconnected from all ports.

If the battery balancing device is in a first working state, the first router (3) is in a working state M11, a port A0 is connected with a port A1, the second router (4) is in a working state M21, a port B0 is connected with a port B1, and an auxiliary charging current Ifc is injected into the positive end of a single battery E1 in the battery pack through the + output end of the auxiliary charging unit;

if the battery balancing device is in a second working state, the first router (3) is in a working state M12, a port A0 is connected with a port A2, the second router (4) is in a working state M22, a port B0 is connected with a port B1, and an auxiliary charging current Ifc is injected into the positive end of a single battery E2 in the battery pack through the + output end of the auxiliary charging unit;

by the way of analogy, the method can be used,

if the battery balancing device is in the nth working state, the first router (3) is in the working state M1n, the port A0 is connected with the port An, the second router (4) is in the working state M2n, the port B0 is connected with the port Bn, and the + output end of the auxiliary charging unit injects auxiliary charging current Ifc to the positive end of the single battery En in the battery pack;

if selected single batteries in the battery pack (1) are the single battery Ei and the single battery Ej, i is more than or equal to 1 and less than or equal to n, j is more than or equal to 1 and less than or equal to n, i is less than or equal to j, the first router (3) is in a working state M1j, the port A0 is connected with Aj, the second router (4) is in a working state M2i, the port B0 is connected with the port Bi, and the auxiliary charging unit + output end injects auxiliary charging current Ifc to the single batteries between the Ei and the Ej in the battery pack;

if the battery balancing device is in the (n + 1) th working state, the A0 of the first router is disconnected with all the ports, and the B0 port of the second router is disconnected with all the ports.

Further, the auxiliary charging unit is a charging converter and is used for providing auxiliary charging current for the selected single battery in the battery pack, when the voltage of the single battery is lower than the upper voltage limit, the converter charges the single battery to be charged with constant current, and when the voltage of the single battery reaches the upper voltage limit, the converter maintains constant voltage output.

Further, the first router and the second router comprise n switches, each switch comprises a common port, a normally closed port and a normally open port, the common port is connected with the normally closed port when the state is not changed, the common port is connected with the normally open port after the state is changed, and the switches preferably adopt relays or MOSFET (metal oxide semiconductor field effect transistor) tubes or IGBT (insulated gate bipolar transistor) tubes or transistors.

Further, the KA1 switch, the KA2 switch, the KA3 switch … … KAn-1 switch and the KAn switch of the first router are connected in such a way that a common port of KA1 is connected with a port of a0, a normally open port is connected with a port of a1, a common port of KA2 is connected with a normally closed port of KA1, a normally open port is connected with a port of a2, a common port of KA3 is connected with a normally closed port of KA2, a normally open port is connected with a port of A3, and so on, a common port of KAn is connected with a normally closed port of KAn-1, and a normally open port is connected with An port;

the KB1 switch, the KB2 switch, the KB3 switch … … KBn-1 switch and the KB KBn switch of the second router are connected in a way that a common port of the KB1 is connected with a port B0, a normally open port is connected with a port B1, a common port of the KB2 is connected with a normally closed port of the KB1, a normally open port is connected with a port B2, a common port of the KB3 is connected with a normally closed port of the KB2, a normally open port is connected with a port B3, and the like, a common port of the KB KBn is connected with a normally closed port of KBn-1, and a normally open port is connected with a port Bn.

Further, the voltage state of the single battery in the battery pack determines the switching state in the first router and the second router, and further determines the working state of the battery balancing device, and the principle of the switching state change is as follows:

if the voltage of a single battery E1 in the battery pack is low, the KA1 switch in the first router changes state, a common port of the first router is connected with a normally open port, other switches do not change state, the common port is connected with a normally closed port, and an A0 port is connected with an A1 port through a KA1 common port and the normally open port; the KB1 switch in the second router changes state, a common port of the KB1 switch is connected with a normally open port, other switches do not change state, the common port is connected with a normally closed port, a B0 port is connected with a B1 port through a KB1 common port and the normally open port, and the battery balancing device is in a first working state under the condition;

if the voltage of the single battery E2 in the battery pack is lower, the KA2 switch in the first router changes state, the common port of the KA2 switch is connected with the normally open port, and other switches do not change state,

the A0 port is connected with the A2 port through a KA1 switch public port and a normally closed port, and a KA2 switch public port and a normally open port are connected with the A1 port; the KB2 switch in the second router changes state, a common port of the KB2 switch is connected with a normally open port, other switches do not change state, a B0 port of the KB2 switch is connected with the common port and the normally closed port through KB1, and the KB2 switch is connected with the common port and the normally open port of the KB2 switch, so that the battery balancing device is in a second working state;

if the voltage of a single battery E3 in the battery pack is low, a KA3 switch in the first router changes states, a common port of the first router is connected with a normally open port, other switches do not change states, the common end is connected with a normally closed port, an A0 port is connected with the common port and the normally closed port through KA1 switches, the KA2 switches the common port and the normally closed port, and a KA3 switch common port and the normally open port are connected with an A3 port; the KB3 switch in the second router changes state, the common port of the KB3 switch is connected with the normally open port, the other switches do not change state, and the common port is connected with the normally closed port; the B0 port is connected with the B3 port through a KB1 switch public port and a normally closed port, a KB2 switch public port and a normally closed port, and a KB3 switch public port and a normally open port are connected with the B3 port, so that the battery balancing device is in a third working state; and so on.

If the working states of a selected single battery E1 and a selected single battery E2 in the battery pack are changed, the KA2 switch in the first router changes the state, a common port of the first router is connected with a normally open port, the other switches keep unchanged, an A0 port is connected with the common port through a KA1 switch, a KA1 switch is connected with a normally closed port, and a KA2 switch common port and the normally open port are connected with an A2 port; the KB1 switch in the second router changes state, the common port of the KB1 switch is connected with the normally-open port, the rest switches are not switched, and the B0 port is connected with the B1 port through the KB1 switch common port and the KB1 normally-open port.

If selected single batteries in the battery pack are the single battery Ei and the single battery Ej, i is more than or equal to 1 and less than or equal to n, j is more than or equal to 1 and less than or equal to n, i and less than j, the KAj switch in the first router changes the state, the public port of the KAj switch is connected with the normally open port, the other switches keep unchanged, the A0 port is connected with the Aj port through the KA1 switch public port and the KA1 switch normally closed port, and the KAj switch public port and the normally open port are connected with the Aj port; the KBi switch in the second router changes state, a common port of the KBi switch is connected with a normally open port, the other switches are not switched, a B0 port is connected with a public port of the KB1 switch and a normally closed port of the KB1 switch, and the KBi common port and the KBi normally open port are connected with a Bi port.

Furthermore, the control unit comprises a bus transceiver, a voltage measuring circuit and a switch driver which are connected with the program controller, the bus transceiver exchanges data with the program controller, the received information is transmitted to the program controller, and the data output by the program controller is also transmitted; the transceiver exchanges data with a main charger of external equipment or an electric appliance or a battery management system through a bus terminal, and a bus protocol supported by the transceiver is a CAN bus or a 485 bus or an RS232 bus.

Further, the input part of the voltage detection circuit is connected to each single battery of the battery, the voltage detection circuit outputs voltage electric measurement signals, the voltage detection signals carry voltage signals of the single batteries in the battery pack, and the voltage detection signals are sent to the program controller; and the program controller generates a state control signal according to the voltage condition of the single batteries in the battery pack and sends the state control signal to the switch driver, the output of the switch driver is a switch driving signal, and the switch driving signal is sent to the first router and the second router to control the state conversion of the first router and the second router so as to form an auxiliary charging loop between the auxiliary charging unit and the single batteries.

Further, the voltage measurement circuit includes n voltage measurement modules, each of the voltage measurement modules is connected in parallel to each of the single batteries or the parallel-serial converter, and the voltage measurement modules output voltage detection signals in parallel.

Further, the power inputs of the auxiliary charging unit are respectively taken from the positive battery pack terminal BAT + and the negative battery pack terminal BAT-.

Compared with the prior similar technology, the battery balancing device of the invention provides an active (active) battery pack balancing management technology: setting a first router and a second router, and using the first router and the second router in combination with the battery pack; by controlling the state transition of the first router and the second router, an auxiliary charging loop can be conveniently formed between the auxiliary charging unit and the single battery with lower voltage in the battery pack to provide auxiliary charging current for the auxiliary charging unit; the technical characteristics of the battery equalization management technology provided by the invention are as follows: the first router and the second router are mutually independent, when in specific application, the first router independently leads the output end of the auxiliary charging unit to the cathode of the single battery with lower voltage, and the second router independently leads the output end of the auxiliary charging unit to the anode of the single battery with lower voltage; the control strategy can effectively reduce the difficulty of the control strategy of the battery pack balance management system; the switches in the first and second routers adopt a serial connection structure, and the serial connection structure utilizes the characteristics of a common port, a normally closed port and a normally open port of a switch device to connect the switches in series end to form a switch chain array; by using the series switch chain array, the first router and the second router can be connected with as many single batteries as possible by using the minimum switch number, and only one switch device needs to be operated when the states of the first router and the second router are switched each time; therefore, when the circuit works, the required current channel can be obtained only by simply controlling the switches in the series switch chain array; obviously, the method reduces the switch number of the road selector to the maximum extent and reduces the switch control difficulty;

the battery pack equalization management technology provided by the invention has the advantages of fewer switching devices and simple switching control, solves the problems of large number of switches and complex and difficult circuit topology in the conventional battery pack equalization tube technology, and also reduces the difficulty of a system control strategy.

Drawings

Fig. 1 is a schematic diagram of an application of a battery equalization apparatus according to the present invention.

Fig. 2 is a schematic diagram of a first working state of the battery equalization apparatus according to the present invention.

Fig. 3 is a schematic diagram of a second working state of the battery equalization apparatus according to the present invention.

Fig. 4 is a schematic view of the nth operating state of the battery equalization apparatus according to the present invention.

Fig. 5 is a schematic diagram of the working states of the battery balancing device according to the present invention when the selected single batteries are E2 and E3.

Fig. 6 is a schematic diagram of a topology structure in which a first router and a second router of the battery balancing device are connected in series by switches.

Fig. 7 is a schematic diagram of switch structures in the first router and the second router of the battery balancing device of the present invention.

Fig. 8 is a schematic diagram of a topology of a switch in a battery equalization apparatus implemented by using MOSFET transistors according to the present invention.

Fig. 9 is a schematic diagram illustrating characteristics of an auxiliary charging unit in the battery equalization apparatus according to the present invention.

Fig. 10 is a schematic structural diagram of a control unit in the battery equalization apparatus of the present invention.

Fig. 11 is a schematic diagram of an implementation scheme of a voltage measurement circuit in a control unit of the battery equalization device.

Fig. 12 is a schematic diagram of the battery equalization apparatus of the present invention using a switch series connection topology, and the current is in a first operating state.

Fig. 13 is a schematic diagram of the battery equalization apparatus of the present invention using a switch series connection topology, showing the current in the second operating state.

Fig. 14 is a schematic current diagram of a battery equalization apparatus using a switched series connection topology in the nth operating state.

Fig. 15 shows a current schematic diagram of the battery balancing device in a switch series connection topology, when selected unit batteries are E1 and E2.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The method aims to at least partially solve the problems in the prior art, such as how to solve the problems of complex circuit topology, difficult equalization management control strategy and the like of the traditional battery pack equalization management method. The embodiment of the invention provides a battery balancing device, wherein the battery balancing device comprises:

the method comprises the following steps:

a battery pack (1);

an auxiliary charging unit (2);

a first router (3);

a second router (4);

a control unit (5);

wherein:

the battery pack (1) comprises n single batteries E1, E2, E3 … …, En-1 and En, the number of the n single batteries is not less than 1 and is connected with the single batteries in a series connection mode, and a positive terminal BAT + of the battery pack (1) is connected with a main charger or a + end and a negative terminal BAT-of an electric appliance and is connected with the main charger or a-end of the electric appliance;

the auxiliary charging unit (2) is connected with the first router (3) and the second router (4) and is used for carrying out auxiliary charging current on the single batteries of which the number is not less than 1;

the first router (3) and the second router (4) comprise n +1 ports and are connected with the battery pack (1) and the control unit (5);

the connection of the A0 port, the A1 port, the A2 port, the A3 port … … An-1 port and An port of the first router (3) is as follows: the port A0 is connected with the output end of the auxiliary charging unit (2), the port A1 is connected with the negative electrode of a single battery E1 in the battery pack (1), the port A2 is connected with the negative electrode of a single battery E2, the other ports are connected in the same way, and the port An is connected with the negative electrode of a single battery En;

the connection of the B0 port, the B1 port, the B2 port, the B3 port … … Bn-1 port and the Bn port of the second router (4) is as follows: the port B0 is connected with the + output end of the auxiliary charging unit (2), the port B1 is connected with the positive electrode of a single battery E1 in the battery pack (1), the port B2 is connected with the positive electrode of the single battery E2, the other ports are connected in the same way, and the port Bn is connected with the positive electrode of a single battery En;

the control unit (5) controls the working state of the first router (3) and the working state of the second router (4) according to the voltage condition of the selected single battery;

if the first router (3) is in a working state M11, the A0 port of the first router (3) is connected with the A1 port;

if the first router (3) is in a working state M12, the A0 port of the first router (3) is connected with the A2 port;

and so on;

if the first router (3) is in a working state M1n, the A0 port of the first router (3) is connected with An port;

if the first router (3) is in a working state M1n +1, the A0 port of the first router (3) is disconnected with all ports;

if the second router (4) is in the working state M21, the B0 port of the second router (4) is connected with the B1 port;

if the second router (4) is in the working state M22, the B0 port of the second router (4) is connected with the B2 port;

and so on;

if the second router (4) is in a working state M2n, connecting a port B0 in the second router (4) with a port Bn;

and if the second router (4) is in the working state M2n +1, the port B0 of the second router (4) is disconnected with all ports.

by the way of analogy, the method can be used,

The auxiliary charging unit (2) is a charging converter and is used for providing auxiliary charging current for the selected single battery in the battery pack (1), when the voltage of the single battery is lower than the upper voltage limit, the converter charges the single battery to be charged with constant current, and when the voltage of the single battery reaches the upper voltage limit, the converter maintains constant voltage output.

The first router (3) and the second router (4) comprise n switches, the switches (31) (41) comprise common ports (311) (411), normally closed ports (312) (412) and normally open ports (313) (413), the common ports (311) (411) are respectively connected with the normally closed ports (312) (412) when the state is not changed, the common ports are respectively connected with the normally open ports (313) (413) after the state is changed, and the switches are preferably relays, MOSFET tubes, IGBT tubes or transistors.

The KA1 switch, KA2 switch, KA3 switch … … KAn-1 switch and KAn switch of the first router (3) are connected in a way that a public port of KA1 is connected with An A0 port, a normally-open port is connected with An A1 port, a public port of KA2 is connected with a normally-closed port of KA1, a normally-open port is connected with An A2 port, a public port of KA3 is connected with a normally-closed port of KA2, a normally-open port is connected with An A3 port, and so on, the public port of KAn is connected with a normally-closed port of KAn-1, and the normally-open port is connected with An port;

the KB1 switch, the KB2 switch, the KB3 switch … … KBn-1 switch and the KBn switch of the second router (4) are connected in a way that a common port of the KB1 is connected with a port of the B0, a normally open port is connected with a port of the B1, a common port of the KB2 is connected with a normally closed port of the KB1, a normally open port is connected with a port of the B2, a common port of the KB3 is connected with a normally closed port of the KB2, a normally open port is connected with a port of the B3, and the like, a common port of the KBn is connected with a normally closed port of the KBn-1, and a normally open port is connected with a port of the Bn.

The voltage state of a single battery in the battery pack (1) determines the switching state in a first router (3) and a second router (4) so as to determine the working state of the battery balancing device, and the principle of switching state change is as follows:

if the voltage of a single battery E1 in the battery pack (1) is lower, a KA1 switch in the first selector (3) changes state, a common port of the KA1 switch is connected with a normally open port, other switches do not change state, the common port is connected with a normally closed port, and an A0 port is connected with an A1 port through a KA1 common port and the normally open port; the KB1 switch in the second router (4) changes state, a common port of the KB1 switch is connected with a normally open port, other switches do not change state, the common port is connected with a normally closed port, a B0 port is connected with a B1 port through the KB1 common port and the normally open port, and the battery balancing device is in a first working state under the condition;

if the voltage of a single battery E2 in the battery pack (1) is lower, the KA2 switch in the first selector (3) changes state, the common port of the KA switch is connected with a normally open port, and other switches do not change state,

the A0 port is connected with the A2 port through a KA1 switch public port and a normally closed port, and a KA2 switch public port and a normally open port are connected with the A1 port; the KB2 switch in the second router (4) changes state, a common port of the KB2 switch is connected with a normally open port, other switches do not change state, a B0 port of the KB2 switch is connected with the common port and a normally closed port through KB1, and a KB2 switch is connected with the common port and the normally open port of the KB2 port, so that the battery balancing device is in a second working state;

if the voltage of a single battery E3 in the battery pack (1) is lower, a KA3 switch in the first selector (3) changes state, a common port of the first selector is connected with a normally open port, other switches do not change state, the common port is connected with a normally closed port, an A0 port is connected with a common port and a normally closed port through a KA1 switch, a KA2 switch common port and a normally closed port are connected, and a KA3 switch common port and a normally open port are connected with an A3 port; the KB3 switch in the second router (4) changes state, the common port of the KB3 switch is connected with the normally open port, the other switches do not change state, and the common port is connected with the normally closed port; the B0 port is connected with the B3 port through a KB1 switch public port and a normally closed port, a KB2 switch public port and a normally closed port, and a KB3 switch public port and a normally open port are connected with the B3 port, so that the battery balancing device is in a third working state; and so on.

If the working states of a selected single battery E1 and a selected single battery E2 in the battery pack (1) are changed, a public port of a KA2 switch in the first selector (3) is connected with a normally open port, other switches are kept unchanged, an A0 port is connected with an A2 port through a KA1 switch public port and a KA1 switch normally closed port, and a KA2 switch public port and the normally open port are connected with the A2 port; the KB1 switch in the second router (4) changes state, a common port of the KB1 switch is connected with a normally open port, the rest switches are not switched, and a B0 port is connected with a B1 port through a KB1 switch common port and a KB1 normally open port;

if selected single batteries in the battery pack (1) are the single battery Ei and the single battery Ej, i is more than or equal to 1 and less than or equal to n, j is more than or equal to 1 and less than or equal to n, and i is less than or equal to j, the KAj switch in the first router (3) changes the state, the common port is connected with the normally open port, the other switches keep unchanged, the A0 port is connected with the Aj port through the KA1 switch common port, the KA1 switch normally closed port, and the KAj switch common port and the normally open port are connected; the KBi switch in the second router (4) changes state, a common port of the KBi switch is connected with a normally open port, the other switches are not switched, a B0 port is connected with a Bi port through a KB1 switch common port and a KB1 normally closed port, and the KBi common port and the KBi normally open port are connected with the Bi port.

The control unit (5) comprises a bus transceiver (51), a voltage measuring circuit (54) and a switch driver (52) which are connected with a program controller (53), the bus transceiver (51) exchanges data with the program controller (53), received information is transmitted to the program controller (53), and data output by the program controller (53) is also transmitted; the transceiver (51) exchanges data with a main charger of an external device, an electric appliance or a battery management system through a bus terminal, and a bus protocol supported by the transceiver is a CAN bus or a 485 bus or an RS232 bus.

The input part of the voltage detection circuit (54) is connected to each single battery of the battery pack (1), the voltage detection circuit (54) outputs voltage electric measurement signals which carry voltage signals of the single batteries in the battery pack (1), and the voltage detection signals are sent to the program controller (53); the program controller (53) generates a state control signal according to the voltage condition of a single battery in the battery pack (1) and sends the state control signal to the switch driver (52), the output of the switch driver (52) is a switch driving signal, the switch driving signal is sent to the first router (3) and the second router (4), and the state conversion of the first router (3) and the second router (4) is controlled to form an auxiliary charging loop between the auxiliary charging unit (2) and the single battery.

The voltage measurement circuit (54) includes n voltage measurement modules, each of which is connected in parallel with each of the unit cells or the parallel-to-serial converter, and outputs voltage detection signals in parallel.

The power supply input of the auxiliary charging unit (2) is respectively taken from the positive terminal BAT + of the battery pack (1) and the negative terminal BAT-of the battery pack (1).

When the battery balancing device works, the control unit (5) controls the first router (3) and the second router (4) to perform state conversion after obtaining the voltage data of each single battery of the battery pack, so as to form an independent auxiliary charging loop between the auxiliary charging unit and a plurality of single batteries with lower voltage or the single battery with lower voltage. In the independent auxiliary charging loop, the lower-voltage single batteries or the single battery with the lowest voltage obtain the auxiliary charging current provided by the auxiliary charging unit, so that the balance control of the battery pack is realized. Compared with the prior similar technology, the battery balancing device of the invention provides an active (active) battery pack balancing management technology: setting a first router and a second router, and using the first router and the second router in combination with the battery pack; by controlling the state transition of the first router and the second router, an auxiliary charging loop can be conveniently formed between the auxiliary charging unit and the single battery with lower voltage in the battery pack to provide auxiliary charging current for the auxiliary charging unit; the technical characteristics of the battery equalization management technology provided by the invention are as follows: the first router and the second router are mutually independent, when in specific application, the first router independently leads the output end of the auxiliary charging unit to the cathode of the single battery with lower voltage, and the second router independently leads the output end of the auxiliary charging unit to the anode of the single battery with lower voltage; the control strategy can effectively reduce the difficulty of the control strategy of the battery pack balance management system; the switches in the first and second routers adopt a serial connection structure, and the serial connection structure utilizes the characteristics of a common port, a normally closed port and a normally open port of a switch device to connect the switches in series end to form a switch chain array; by using the series switch chain array, the first router and the second router can be connected with as many single batteries as possible by using the minimum switch number, and only one switch device needs to be operated when the states of the first router and the second router are switched each time; therefore, when the circuit works, the required current channel can be obtained only by simply controlling the switches in the series switch chain array; obviously, the method reduces the switch number of the road selector to the maximum extent and reduces the switch control difficulty;

Fig. 1 is a schematic application diagram of a battery equalization apparatus according to an embodiment of the present invention; the battery equalization device shown in fig. 1 can connect the auxiliary charging unit (2) to the two ends of the single battery with lower voltage respectively and independently through the first router (3) and the second router (4), so as to provide auxiliary charging current for the single battery. The battery equalization device comprises a battery pack (1), an auxiliary charging unit (2), a first router (3), a second router (4) and a control unit (5).

The battery pack (1) comprises n single batteries E1 and E2, the single battery E3 … is a single battery En-1, the single battery En, n is not less than 1, and the single batteries are connected in series. The positive terminal BAT + of the battery pack (1) is connected with the main charger or the electrical appliance + terminal, and the negative terminal BAT-of the battery pack (1) is connected with the main charger or the electrical appliance-terminal.

The auxiliary charging unit (2) is a constant-current and constant-voltage converter and is used for carrying out auxiliary charging on the single batteries in the battery pack (1). The constant-current and constant-voltage converter is characterized in that: when the voltage of the single battery is lower than the upper voltage limit, the converter carries out constant current charging on the single battery to be charged, and when the voltage of the single battery reaches the upper voltage limit, the converter maintains constant voltage output.

The first router (3) comprises n +1 ports: the battery pack comprises An A0 port, An A1 port, An 2 port, An 3 port, …, An-1 port and An port, wherein n is the number of single batteries in the battery pack (1), and the connection rules of the ports are as follows: the port A0 is connected with the output end of the auxiliary charging unit (2), the port A1 is connected with the negative electrode of a single battery E1 in the battery pack (1), the port A2 is connected with the negative electrode of a single battery E2, …, and the like, and the port An is connected with the negative electrode of a single battery En.

The second router (4) comprises n +1 ports: b0 port, B1 port, B2 port, B3 port, …, Bn-1 port and Bn port, wherein n is the number of single batteries in the battery pack (1), and the connection rules of the ports are as follows: the port B0 is connected with the + output end of the auxiliary charging unit (2), the port B1 is connected with the positive electrode of a single battery E1 in the battery pack (1), the port B2 is connected with the positive electrode of a single battery E2, …, and the like, and the port Bn is connected with the positive electrode of a single battery En.

Fig. 2 is a schematic diagram of an operating state of the battery equalization apparatus according to the present invention. In the first operating state, the port A0 of the first selector (3) is connected with the port A1, and the output end of the auxiliary charging unit (2) is connected with the negative end of a single battery E1; in the second router (4), a port B0 is connected with a port B1, the + output end of the auxiliary charging unit is connected with the positive end of a single battery E1, and the auxiliary charging unit (2) injects auxiliary charging current Ifc into the single battery E1 through a port B0, a port B1, a port A1 and a port A0.

Fig. 3 is a schematic diagram of two working states of the battery equalization apparatus of the present invention. In the second operating state, the port A0 of the first selector (3) is connected with the port A2, and the output end of the auxiliary charging unit (2) is connected with the negative end of a single battery E2; in the second router (4), a port B0 is connected with a port B2, the output end of the auxiliary charging unit (2) + is connected with the positive end of a single battery E2, and the auxiliary charging unit (2) injects auxiliary charging current Ifc into the single battery E2 through the port B0, the port B2, the port A2 and the port A0.

Fig. 4 is a schematic diagram of n operating states of the battery equalization apparatus according to the present invention. In the nth working state, in the first router (3), the port A0 is connected with the port An, and the output end of the auxiliary charging unit (2) is connected with the negative end of the single battery En; in the second router (4), a port B0 is connected with a port Bn, the output end of the auxiliary charging unit (2) + is connected with the positive end of the single battery En, and the auxiliary charging unit (2) injects auxiliary charging current Ifc into the single battery En through the port B0, the port Bn, the port An and the port A0.

Fig. 5 is a schematic diagram of the battery balancing apparatus according to the present invention in the operating states of the selected cell E2 and the cell E3. The first selector (3) is in a working state M13, the A0 port is connected with the A3 port, and the output end of the auxiliary charging unit (2) is connected with the negative end of a single battery E3; the second router (4) is in a working state M22, a port B0 is connected with a port B2, the output end of the auxiliary charging unit (2) + is connected with the positive end of the single battery E2, and the auxiliary charging unit (2) injects auxiliary charging current Ifc into the single battery E2 and the single battery E3 through the port B0, the port B2, the port A3 and the port A0.

Fig. 6 is a schematic diagram of a topology structure in which the first router (3) and the second router (4) of the battery balancing device are connected in series by using switches. Referring to fig. 6, the first selector (3) includes n switches (31), which are KA1 switch, KA2 switch … KA3 switch, KAn-1 switch, KAn switch, respectively. The second router (4) includes n switches (41), which are a KB1 switch, a KB2 switch, a KB3 switch … KBn-1 switch, and a KBn switch, respectively.

Fig. 7 is a schematic diagram of the switch structure. Referring to fig. 7, the switches (31) and (41) respectively include a common port 311 and a common port 411, a normally closed port 312 and a normally closed port 412, and a normally open port 313 and a normally open port 413, and the switches (31) and (41) preferably adopt relays. Referring to fig. 7a, when the state of the switches (31) and (41) is not changed, the common port 311 is connected with the normally closed port 312, and the common port 411 is connected with the normally closed port 412. Referring to fig. 7b, after the state change, the switches (31, 41) connect the common port 311 to the normally open port 313, and the common port 411 to the normally open port 413.

With continuing reference to fig. 6 in conjunction with fig. 7, the n switches in the first router (3) are connected in series by:

the common port 311 of the KA1 switch is connected with the A0 port, and the normally open port 313 is connected with the A1 port; the common port of the KA2 switch is connected with the normally closed port 312 of the KA1, and the normally open port of the KA2 switch is connected with the A2 port; a common port of the KA3 switch is connected with a normally closed port of the KA2 switch, and a normally open port of the KA3 switch is connected with an A3 port; …, respectively; by analogy, the common port of the KAn switch is connected with the normally closed port of the KAn-1 switch, and the normally open port of the KAn-1 switch is connected with the An port.

The n switches in the second router (4) are connected in series, and the connection method is as follows:

the common port of the KB1 switch is connected to the B0 port, and the normally open port of the KB1 switch is connected to the B1 port; the common port of the KB2 switch is connected to the normally closed port of the KB1, and the normally open port of the KB2 switch is connected to the B2 port; the common port of the KB3 switch is connected with the normally closed port of the KB2 switch, and the normally open port of the KB3 switch is connected with the B3 port; …, respectively; by analogy, the common port of the KBn switch is connected to the normally closed port of the KBn-1 switch, and the normally open port of the KBn switch is connected to the Bn port.

Fig. 8 is a schematic diagram of a topology of a switch in the battery balancing apparatus implemented by using MOSFET transistors according to the present invention. Referring to fig. 8, the switch (31) includes a MOSFET switch tube S1 and a switch tube S2. The drain of the switch tube S1 and the source of the switch tube S2 are connected to the common port 311, the source of the switch tube S1 is connected to the normally closed port 312, and the drain of the switch tube S2 is connected to the normally open port 313. The switch 41 comprises a MOSFET switch tube S3 and a switch tube S4. The source of the switch tube S3 is connected to the drain of the switch tube S4 and to the common port 411, the drain of the switch tube S3 is connected to the normally closed port 412, and the source of the switch tube S4 is connected to the normally open port 413.

Fig. 9 is a schematic diagram of the characteristics of the auxiliary charging unit (2) in the battery equalization apparatus of the present invention, and the constant current and constant voltage characteristics of the auxiliary charging unit (2) can be explained according to fig. 9. The abscissa of the graph is time and the ordinate is voltage (left) and current (right), respectively. Referring to fig. 9, it is assumed that the auxiliary charging unit (2) performs auxiliary charging of the selected cell voltage at time T0. Further, if the voltage of the selected single battery is Vo and Vo is less than Vmax, the auxiliary charging unit (2) is in a constant current mode at the moment, namely, the selected single battery is subjected to constant current charging. The constant-current charging is technically characterized in that the auxiliary charging unit (2) charges the single batteries with a current of a constant value Ic. As can be seen from fig. 9, the voltage of the unit cells increases as the charging time increases. Assuming that the cell voltage reaches the maximum value Vmax at the time Tfull, the auxiliary charging unit will be changed from the constant-current charging mode to the constant-voltage mode at this time. The constant voltage mode is technically characterized in that the auxiliary charging unit (2) maintains the output voltage at a Vmax constant value and inhibits the voltage of the selected single battery from continuously increasing.

Fig. 10 is a schematic structural diagram of a control unit in the battery equalization apparatus of the present invention. Referring to fig. 10, the control unit (5) includes a bus transceiver 51, a switch driver 52, a program controller 53, and a voltage measuring circuit 54. The program controller 53 is connected to the bus controller 51, the switch driver 52, and the voltage measuring circuit 54, respectively. The bus transceiver 51 exchanges data with the program controller 53, and transmits information received from the outside to the program controller, and also transmits data output from the program controller. The transceiver 51 communicates with an external device, which is a main charger or an electrical appliance, or a battery management system, through a bus terminal. The bus protocol supported by the transceiver CAN be a CAN bus, a 485 bus, an RS232 bus and the like, and CAN also be other bus protocols.

With continued reference to fig. 10, the voltage detection circuit 54 inputs the individual cells partially connected to the battery pack (1), and the voltage detection circuit 54 outputs as voltage electrical measurement signals carrying voltage signals of the individual cells in the battery pack (1), which are sent to the program controller 53. The program controller 53 generates a state control signal according to the voltage condition of the single battery in the battery pack and sends the state control signal to the switch driver 52. The output of the switch driver 52 is a switch driving signal, which is sent to the first router (3) and the second router (4) to control the state transition of the first router (3) and the second router (4).

With continued reference to fig. 10, the cell voltages obtained by the program controller 53 may be obtained by directly measuring the cell voltages by the voltage measuring circuit 54; or may be obtained by exchanging data with an external device such as a main charger, a consumer, or a battery management system through a bus by means of the bus transceiver 51.

Fig. 11 is a schematic diagram of an implementation scheme of a voltage measurement circuit in a control unit of the battery equalization device. Referring to fig. 11a, the voltage measurement circuit 54 includes n voltage measurement modules V1, V2, …, Vn-1, Vn. The connection mode of the voltage measurement module is as follows: the voltage measurement module V1 is connected with the single battery E1 in parallel, the voltage measurement module V2 is connected with the single batteries E2 and … in parallel, the voltage measurement module Vn-1 is connected with the single battery En-1 in parallel, and the voltage measurement module Vn is connected with the single battery En in parallel. Further, the outputs of the voltage measurement module V1, the voltage measurement modules V2, …, the voltage measurement module Vn-1 and the voltage measurement module Vn constitute the voltage detection signal, and the voltage detection signal is output in parallel.

Referring to fig. 11a and 11b, in order to solve the problem that the number of the voltage detection signals is large in the case that there are many single batteries in the battery pack, fig. 11b adds a parallel-serial converter to fig. 11 a. The parallel voltage detection signals can be converted into serial signals by the parallel-serial converter and sent to the program controller.

Fig. 12 is a schematic diagram of the battery equalization apparatus of the present invention using a switch series connection topology, and the current is in a first operating state. Referring to fig. 12, in the first operating condition,

the KA1 switch in the first selector (3) is switched, the other switches are not switched, at the moment, the common port 1-311 of the KA1 switch is connected with the normally-open port 1-313, the A0 port is connected with the A1 port through the KA1 switch common port 1-311 and the KA1 switch normally-open port 1-313, and the output end of the auxiliary charging unit (2) is connected to the negative electrode of the single battery E1 through the A0 port and the A1 port.

The KB1 switch in the second router (4) is switched, the rest switches are not switched, the common port 1-411 of the KB1 switch is connected with the normally-open port 1-413, the B0 port is connected with the B1 port through the common port 1-411 of the KB1 switch and the normally-open port 1-413 of the KB1 switch, and the + output end of the auxiliary charging unit (2) is connected to the anode of the single battery E1 through the B1 port and the B0 port.

Through the conversion of the KA1 switch and the KB1 switch, a channel for auxiliary charging of the battery cell E1 is established independently: the charging system comprises an auxiliary charging unit + output end, a B0 port, KB1 switch common ports 1-411, KB1 switch normally-open ports 1-413, a B1 port, a cell E1 positive end, a cell E1 negative end, an A1 port, KA1 switch normally-open ports 1-313, KA1 switch common ports 1-311, an A0 port and an auxiliary charging unit-output end. Through this auxiliary charging path, the auxiliary charging unit (2) supplies an auxiliary charging current to the unit cell E1.

Fig. 13 is a schematic diagram of the battery equalization apparatus of the present invention using a switch series connection topology, showing the current in the second operating state. Referring to fig. 13, in the second operating condition,

the KA2 switches in the first selector (3) are switched, the other switches are kept not switched, at this time, the public ports 2-311 of the KA2 switches are connected with the normally open ports 2-313, the A0 ports are connected with the normally closed ports 1-312 of the KA1 switches through the public ports 1-311 of the KA1 switches and the KA1 switches, the KA2 switches are connected with the ports of the A2 through the public ports 2-311 of the KA2 switches and the normally open ports 2-313 of the KA switches, and the output end of the auxiliary charging unit (2) is connected to the negative electrode of the single battery E2 through the ports A0 and the A2.

The KB2 switch in the second router (4) is switched, the other switches are not switched, at the moment, the public ports 2-411 of the KB2 switch are connected with the normally open ports 2-413, the B0 port is connected with the normally closed ports 1-412 of the KB1 switch through the public ports 1-411 of the KB1 switch and the KB1 switch through the normally open ports 1-412 of the KB1 switch, the public ports 2-411 of the KB2 switch and the normally open ports 2-413 of the KB2 switch are connected with the B2 port, and the + output end of the auxiliary charging unit (2) is connected to the anode of the single battery E2 through the B0 port and the B2 port.

Through the conversion of the KA2 switch and the KB2 switch, a channel for auxiliary charging of the battery cell E2 is established independently: the auxiliary charging unit comprises an auxiliary charging unit + output end, a B0 port, KB1 switch common ports 1-411, KB1 switch normally closed ports 1-412, KB2 switch common ports 2-411, KB2 switch normally open ports 2-413, B2 ports, a single battery E2 positive end, a single battery E2 negative end, an A2 port, a KA2 switch normally open port 2-313, KA2 switch common ports 2-311, KA1 switch normally closed ports 1-312, KA1 switch common ports 1-311, an A0 port and an auxiliary charging unit output end. Through this auxiliary charging path, the auxiliary charging unit (2) supplies an auxiliary charging current to the unit cell E2.

Fig. 14 is a schematic current diagram of a battery equalization apparatus using a switched series connection topology in the nth operating state. Referring to fig. 14, in the nth operating state,

the KAn switch in the first router (3) is switched, the other switches are not switched, the common port n-311 of the KAn switch is connected with the normally open port n-313, the A0 port is connected with the common port of the KAn-1 switch through the KA1 switch, the KA1 switch is connected with the normally closed port of the KAn-1 switch, the common port n-311 of the KAn switch and the normally open port n-313 of the KAn switch are connected with the An port, and the-output end of the auxiliary charging unit (2) is connected with the cathode of the single battery En through the A0 port and the An port.

The KBn switch in the second router (4) toggles and the remaining switches remain un-toggled, with the common port n-411 of the KBn switch connected to the normally open port n-413. The port B0 is connected with the port Bn through a common port of a KB1 switch to a KBn-1 switch, a normally closed port of a KB1 switch to a KBn-1 switch and normally open ports n-411 and KBn of a KBn switch, and the + output end of the auxiliary charging unit (2) is connected to the anode of the single battery En through the port B0 and the port Bn.

Through the switching of the KAn switch and the KBn switch, a channel for auxiliary charging of the single battery En independently is established: auxiliary charging unit + output terminal, B0 port, common port of KB1 switch to KBn-1 switch and normally closed port of KB1 switch to KBn-1 switch, KBn switch common port n-411, KBn switch normally open port n-413, Bn port, cell En positive terminal, cell En negative terminal, An port, KAn switch normally open port n-313, KAn switch common port n-311, KA1 switch to normally closed port of KAn-1 switch and KA1 switch to common port of KAn-1 switch, A0 port, auxiliary charging unit-output terminal. Through this auxiliary charging channel, the auxiliary charging unit (2) supplies an auxiliary charging current to the unit battery En.

Fig. 15 is a schematic current diagram of the battery balancing device adopting a switch series connection topology, in the case that the selected single batteries are E1 and E2. Referring to fig. 15, in this case:

the switches of KA2 in the first selector (3) are switched, the other switches are not switched, at the moment, the common port 2-311 of the KA2 is connected with the normally open port 2-313, the A0 port is connected with the normally closed port 1-312 of the KA1 through the common port 1-311 of the KA1 switch, the normally open port 2-313 of the KA2 switch is connected with the port A2, and the output end of the auxiliary charging unit (2) is connected to the negative electrode of the single battery E1 through the port A0 and the port A2.

Through the conversion of the KA2 switch and the KB1 switch, channels for auxiliary charging of the unit batteries E1 and E2 are established independently: the charging system comprises an auxiliary charging unit + output end, a B0 port, KB1 switch common ports 1-411, KB1 switch normally-open ports 1-413, a B1 port, a cell E1 positive end, a cell E1 negative end, a cell E2 positive end, a cell E2 negative end, an A2 port, a KA2 switch normally-open port 2-313, a KA2 common port 2-311, a KA1 switch normally-closed port 1-312, a KA1 common port 1-311, an A0 port and an auxiliary charging unit-output end. Through this auxiliary charging channel, the auxiliary charging unit (2) supplies auxiliary charging current to the unit batteries E1 and E2.

With further reference to fig. 2, fig. 3, fig. 4, fig. 5, fig. 12, fig. 13, fig. 14, and fig. 15, in the operation of the battery equalization apparatus of the present invention, the voltage status of the single battery in the battery pack determines the switch status in the first router (3) and the second router (4), and further determines the operation status of the battery equalization apparatus, and the principle of the switch changing status is as follows:

if the voltage of a single battery E1 in the battery pack is lower, the KA1 switch in the first router changes the state, the common port of the first router is connected with the normally open port, meanwhile, the KA2 switch, the KA3 switch, the … switch, the KAn-1 switch and the KAn switch do not change the state, the common port is connected with the normally closed port, and the A0 port is connected with the A1 port through the KA1 switch common port and the normally open port; the KB1 switch in the second router changes state, a common port of the KB1 switch is connected with a normally open port, the KB2 switch, the KB3 switch, the KB … switch, the KBn-1 switch and the KBn switch do not change state, the common end of the KB1 switch is connected with the normally closed port, a B0 port is connected with a B1 port through the KB1 switch common port and the normally open port, and the battery balancing device is in a first working state under the condition;

if the voltage of a single battery E2 in the battery pack is lower, the KA2 switch in the first selector changes the state, the common port of the first selector is connected with the normally open port, meanwhile, the KA1 switch, the KA3 switch, the KA … switch, the KAn-1 switch and the kAn switch do not change the state, the A0 port is used for switching the common port and the normally closed port through the KA1 switch, and the KA2 common port and the normally open port are connected with the A2 port; the KB2 in the second router changes the state, a public port of the second router is connected with a normally open port, the KB1 switch, the KB3 switch, the … switch, the KBn-1 switch and the KBn switch do not change the state, the public port is connected with a normally closed port, a B0 port is connected with the public port and the normally closed port of the KB1 switch, and the public port and the normally open port of the KB2 switch are connected with a B2 port, and under the condition, the battery balancing device is in a second working state;

if the voltage of a single battery E3 in the battery pack (1) is lower, the KA3 switch in the first selector changes the state, the common port of the first selector is connected with the normally open port, meanwhile, the KA1 switch, the KA2 switch, the KA4 switch, …, the KAn-1 switch and the kAn switch do not change the state, the A0 port is connected with the A3 port through the KA1 switch common port and the normally closed port, the KA2 switch common port and the normally closed port, and the KA3 switch common port and the normally open port are connected with the A3 port; the KB3 switch in the second router changes state, a common port of the KB3 switch is connected with a normally open port, the KB1 switch, the KB2 switch, the KB4 switch, the KB … switch, the KBn-1 switch and the KBn switch do not change state, the common port is connected with a normally closed port, the B0 port is connected with the KB1 switch common port and the normally closed port, the KB2 switch common port and the normally closed port, and the KB3 switch common port and the normally open port are connected with the B3 port, so that the battery equalization device is in a third working state;

…；

and so on.

It will be appreciated that with respect to fig. 2-5 and 12-15, the circuits and components through which current flows are illustrated by solid black lines and components through which current does not flow are illustrated by dashed lines, the current being the auxiliary charging current provided by the auxiliary charging unit (2).

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the foregoing storage media include (but are not limited to): various media capable of storing program codes, such as a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, and an optical disk.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery equalization apparatus, comprising:

a battery pack (1);

an auxiliary charging unit (2);

a first router (3);

a second router (4);

a control unit (5);

wherein:

the battery pack (1) comprises n single batteries E1, E2, E3 … …, En-1 and En, the number of the n single batteries is not less than 1 and the n single batteries are connected in series, and a positive terminal BAT + of the battery pack (1) is connected with a + end and a negative terminal BAT + of a main charger or an electric appliance and is connected with a + end and a negative end of the main charger or the electric appliance;

the control unit (5) controls the working state of the first router (3) and the working state of the second router (4) according to the voltage condition of the selected single battery:

and so on;

2. A battery equalization apparatus as claimed in claim 1, wherein: if the battery balancing device is in a first working state, the first router (3) is in a working state M11, a port A0 is connected with a port A1, the second router (4) is in a working state M21, a port B0 is connected with a port B1, and an auxiliary charging current Ifc is injected into the positive end of a single battery E1 in the battery pack through the + output end of the auxiliary charging unit;

by the way of analogy, the method can be used,

3. A battery equalization apparatus as claimed in claim 1, wherein: the auxiliary charging unit (2) is a charging converter and is used for providing auxiliary charging current for the selected single battery in the battery pack (1), when the voltage of the single battery is lower than the upper voltage limit, the converter charges the single battery to be charged with constant current, and when the voltage of the single battery reaches the upper voltage limit, the converter maintains constant voltage output.

4. A battery equalization apparatus as claimed in claim 2, wherein: the first router (3) and the second router (4) comprise n switches (31) (41), the switches (31) (41) comprise common ports (311) (411), normally closed ports (312) (412) and normally open ports (313) (413), the common ports (311) (411) are respectively connected with the normally closed ports (312) (412) when the state is not changed, the common ports are respectively connected with the normally open ports (313) (413) after the state is changed, and the switches are preferably relays or MOSFET tubes or IGBT tubes or transistors.

5. A battery equalization apparatus according to claim 1 or 4, characterized in that: the KA1 switch, KA2 switch, KA3 switch … … KAn-1 switch and KAn switch of the first selector (3) are connected in the following way: the common port of the KA1 is connected with the A0 port, the normally open port is connected with the A1 port, the common port of the KA2 is connected with the normally closed port of the KA1, the normally open port is connected with the A2 port, the common port of the KA3 is connected with the normally closed port of the KA2, the normally open port is connected with the A3 port, and the like, the common port of the KAn is connected with the normally closed port of the KAn-1, and the normally open port is connected with the An port;

the KB1 switch, the KB2 switch, the KB3 switch … … KBn-1 switch and the KBn switch of the second router (4) are connected in a way that: the common port of the KB1 is connected with the port B0, the normally open port is connected with the port B1, the common port of the KB2 is connected with the normally closed port of the KB1, the normally open port is connected with the port B2, the common port of the KB3 is connected with the normally closed port of the KB2, the normally open port is connected with the port B3, and the like, the common port of the KBn is connected with the normally closed port of KBn-1, and the normally open port is connected with the port Bn.

6. A battery equalization apparatus according to claims 1-5, characterized in that: the voltage state of a single battery in the battery pack (1) determines the switching state in a first router (3) and a second router (4) so as to determine the working state of the battery balancing device, and the principle of switching state change is as follows:

if the voltage of a single battery E2 in the battery pack (1) is lower, a KA2 switch in the first selector (3) changes state, a common port of the first selector is connected with a normally open port, other switches do not change state, an A0 port is connected with a common port and a normally closed port through KA1 switches, and a KA2 switch common port and the normally open port are connected with an A2 port; the KB2 switch in the second router (4) changes state, a common port of the KB2 switch is connected with a normally open port, other switches do not change state, a B0 port of the KB2 switch is connected with the common port and a normally closed port through KB1, and a KB2 switch is connected with the common port and the normally open port of the KB2 port, so that the battery balancing device is in a second working state;

If the selected single batteries in the battery pack (1) are E1 and E2, the KA2 switch in the first selector (3) changes state, a common port of the first selector is connected with a normally open port, the other switches keep unchanged, an A0 port is connected with an A2 port through a KA1 switch common port and a KA1 switch normally closed port, and a KA2 switch common port and the normally open port are connected; the KB1 switch in the second router (4) changes state, a common port of the KB1 switch is connected with a normally open port, the rest switches are not switched, and a B0 port is connected with a B1 port through a KB1 switch common port and a KB1 normally open port;

if selected single batteries in the battery pack (1) are the single battery Ei and the single battery Ej, i is more than or equal to 1 and less than or equal to n, j is more than or equal to 1 and less than or equal to n, and i is less than or equal to j, the KAj switch in the first router (3) changes the state, the common port is connected with the normally open port, the other switches keep unchanged, the A0 port is connected with the Aj port through the KA1 switch common port, the KA1 switch normally closed port, the KAj switch common port and the KAj normally open port; the KBi switch in the second router (4) changes state, a common port of the KBi switch is connected with a normally open port, the other switches are not switched, a B0 port is connected with a Bi port through a KB1 switch common port and a KB1 normally closed port, and the KBi common port and the KBi normally open port are connected with the Bi port.

7. A battery equalization apparatus as claimed in claim 6, wherein: the control unit (5) comprises a bus transceiver (51), a voltage measuring circuit (54) and a switch driver (52) which are connected with a program controller (53), the bus transceiver (51) exchanges data with the program controller (53), received information is transmitted to the program controller (53), and data output by the program controller (53) is also transmitted; the transceiver (51) exchanges data with a main charger of an external device or an electric appliance or a battery management system through a bus terminal, and the transceiver supports a CAN bus or a 485 bus or an RS232 bus.

8. A battery equalization apparatus as claimed in claim 7, wherein: the input part of the voltage detection circuit (54) is connected to each single battery of the battery pack (1), the voltage detection circuit (54) outputs voltage electric measurement signals which carry voltage signals of the single batteries in the battery pack (1), and the voltage detection signals are sent to the program controller (53); the program controller (53) generates a state control signal according to the voltage condition of a single battery in the battery pack (1) and sends the state control signal to the switch driver (52), the output of the switch driver (52) is a switch driving signal, the switch driving signal is sent to the first router (3) and the second router (4), and the state conversion of the first router (3) and the second router (4) is controlled to form an auxiliary charging loop between the auxiliary charging unit (2) and the single battery.

9. A battery equalization apparatus as claimed in claim 8, wherein: the voltage measurement circuit (54) includes n voltage measurement modules, each of which is connected in parallel with each of the unit cells or the parallel-to-serial converter, and outputs voltage detection signals in parallel.

10. A battery equalization apparatus according to any one of claims 1-9, wherein: the power supply input of the auxiliary charging unit (2) is respectively taken from the positive terminal BAT + of the battery pack (1) and the negative terminal BAT-of the battery pack (1).