CN210327054U

CN210327054U - Hybrid lithium battery voltage equalization circuit topological structure

Info

Publication number: CN210327054U
Application number: CN201920626441.0U
Authority: CN
Inventors: 刘刚; 周玉燕; 龚毅
Original assignee: Yanfeng Visteon Electronic Technology Nanjing Co Ltd
Current assignee: Yanfeng Visteon Electronic Technology Nanjing Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-04-14
Anticipated expiration: 2029-04-30

Abstract

The utility model provides a mixed type lithium cell voltage equalizer circuit topological structure cascades by a plurality of balanced modules and forms, balanced module include the SubPack and with the parallelly connected MOS of SubPack_SPA battery group consisting of a plurality of lithium batteries connected in series and MOS_SPThe tube bank comprises two pairs of MOS in anti-series connection_SPEach lithium battery in the sub pack is connected with a discharge resistor and a switch tube MOS in parallel_cellDischarge resistor and switching tube MOS_cellAre connected in series. The utility model discloses combine to cascade type equalizer circuit and resistance power consumption circuit, carry out the equilibrium to little battery module and battery monomer respectively, improve balanced efficient and have bypass trouble battery function. Compared with the conventionalEqualization circuit, the utility model discloses no energy shifts mutually, and the whole group of direct control is balanced, possesses the redundant characteristics of trouble, guarantees balanced reliable, quick, effective realization.

Description

Hybrid lithium battery voltage equalization circuit topological structure

Technical Field

The utility model belongs to the technical field of the lithium cell is balanced, a mixed type lithium cell voltage equalizer circuit topological structure is related to.

Background

The equalization circuit at the present stage can realize the battery equalization function to a certain extent, but certain problems still exist in the equalization control process, the passive equalization circuit is simple and easy to realize, the stability is good, but the equalization efficiency is low, and energy loss exists; the active equalization loss is small, the equalization efficiency is high, but the circuit elements are more, and the control strategy is complex.

Disclosure of Invention

Aiming at the problems of complex control strategy, more circuit components and parts, incapability of shielding failure batteries and the like in the conventional energy transfer type battery equalization scheme, the utility model provides a hybrid type lithium battery voltage equalization circuit topological structure, which combines a cascade type equalization circuit and a resistance energy consumption circuit to realize the equalization among the battery packs and the equalization of battery monomers inside the battery packs, and the inter-pack equalization can be synchronously performed to improve the equalization efficiency; by controlling MOS in parallel at the same time_SPAnd the fault SubPack is bypassed, and the fault redundancy function is realized.

In order to achieve the above purpose, the utility model provides a following technical scheme:

the utility model provides a hybrid lithium cell voltage equalizer circuit topological structure, is cascaded by a plurality of balanced modules and forms, balanced module includes the SubPack and organizes with the parallelly connected MOS of SubPack, the SubPack is established ties by a plurality of lithium cells and forms, MOS is organized and is included two pairs of MOS pipes of anti-series connection, every lithium cell is parallelly connected in the SubPack has discharge resistance and switch, discharge resistance and switch series connection.

Further, the SubPack in one equalizing module comprises 12-14 lithium batteries.

Further, the switch is an MOS tube.

Compared with the prior art, the utility model has the advantages of as follows and beneficial effect:

1. the utility model discloses combine to cascade type equalizer circuit and resistance power consumption circuit, carry out the equilibrium to little battery module and battery monomer respectively, improve balanced efficient and have bypass trouble battery function.

2. The utility model provides an equalizer circuit structure is very simple, and modular design changes in the extension.

3. For traditional equalizer circuit, the utility model discloses no energy shifts mutually, and the whole group of direct control is balanced, possesses the redundant characteristics of trouble, guarantees balanced reliable, quick, effective realization.

Drawings

Fig. 1 is a schematic diagram of a topology structure of a hybrid equalization circuit according to the present invention.

Fig. 2 is a schematic diagram of charging and discharging of a cascade type equalization circuit composed of 3 Sub _ Pack groups.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings and embodiments, which are to be understood as illustrative only and not limiting the scope of the invention. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

As shown in figure 1, the utility model discloses according to current lithium cell voltage sampling chip characteristic, establish ties 12-14 lithium cells into little group battery, be called SubPack. Taking the example of Subpack1, each set of Subpack is connected to two pairs of anti-series MOS_SPThe tubes (S11, S12, S13, S14) are connected in parallel, and the discharge resistor and the switching tube MOS are connected in parallel_cellAfter the series connection, the series connection is connected with each battery cell in the sub pack in parallel to finally form an equalization module, and a plurality of equalization modules (sub pack1, sub pack2 … … sub pack n) are cascaded to form a battery pack. SubPack parallel MOS_SPThe method can ensure the isolation of different sub-packs and realize the complete control of the sub-packs. Anti-series MOS for controlling upper and lower bridge arms_SPThe switching state of the tube realizes the connection or bypass of the sub pack and the main circuit, so that the circulation path of the charging and discharging current is changed, and the aim of maintaining the balance of each sub pack is finally fulfilled; MOS (metal oxide semiconductor) for controlling switching tube connected with discharge resistor in series_cellAnd the balance of the battery cells in the Subpack group is realized.

When one or more lithium battery single bodies in the Subpack are monitored to have faults, the MOS of the lower bridge arm is controlled_SPTubular shapeThe state bypasses the fault SubPack to forcibly separate the fault battery from the main circuit, and other subpacks can still continue to normally work, thereby providing reliable guarantee for the safe work and personal safety of the battery pack.

Specifically, for the purpose of analysis, each of the cascade module MOS is defined_SPThe switching tube function expresses the on-off state of the switching tube:

namely, the two working states of the lithium battery are respectively as follows:

when S is_iWhen the current is 1(i is 1,2.. n), the upper bridge arm is switched on, the lower bridge arm is switched off, and the battery Sub _ Pack_iAnd (i 1,2.. n) is connected to the main circuit, current flows through the battery, and the battery is charged and discharged.

When S is_iWhen the current is 0(i is 1,2.. n), the upper bridge arm is turned off, the lower bridge arm is turned on, and the battery Sub _ Pack is connected to the upper bridge arm_iAnd (i ═ 1,2.. n) bypasses the main circuit, so that current does not flow through the battery, and the battery is not charged and discharged.

The current flowing Sub _ Pack can be changed according to the switch state_iA path. In the charging and discharging process, two pairs of MOS (metal oxide semiconductor) are controlled by an upper bridge arm and a lower bridge arm_SPThe working state of the switching tube can change the circulation path of the charging and discharging current, realize the control of the charging and discharging time of the battery and finally maintain each Sub _ Pack_iRelative SOC balance of (Sub _ Pack)_iThe hybrid type balancing method can improve the effective capacity of the battery pack, reduce the influence of a conventional balancing scheme on the service life of the lithium battery and improve the balancing efficiency.

As shown in fig. 2, the following description will take a cascade equalization circuit composed of 3 Sub _ packs as an example to illustrate the topology structure of the hybrid lithium battery voltage equalization circuit, wherein, in the discharging state, the Sub _ Pack is used_iThe SOC of the minimum battery monomer in the battery pack is used as a calculation index; in the charging state, with Sub _ Pack_iThe SOC of the minimum battery cell is used as a calculation index. Analysis of Charge and dischargePrinciple of equalization.

And (3) equalizing analysis in the charging process: in the battery Pack charging process, it is assumed that the lithium battery Sub _ Pack is detected in the kth sampling period₂Has a large SOC (system on chip) and controls each MOS_SPThe switch tube is actuated and the switch state is S₁＝1,S₂＝0,S₃When the battery Sub _ Pack is equal to 1₂Bypassing the main circuit, battery Sub _ Pack₁And Sub _ Pack₃When the main circuit is switched on, the current flows instantaneously as shown in figure 2. The charging current will flow through the battery Sub _ Pack₁And Sub _ Pack₃Without flowing through Sub _ Pack₂I.e. battery Sub _ Pack₁And Sub _ Pack₃Charging is continued while the battery Sub _ Pack₂Stopping charging, thus realizing the battery Sub _ Pack₁And Sub _ Pack₃Multiple charging, and the battery Sub _ Pack₂Charging is less. In the same way, the battery Sub _ Pack₁SOC or battery Sub _ Pack of₃When the SOC of (1) is larger, the corresponding MOS is controlled_SPAnd the switch tube acts, so that the battery with low SOC is charged more, the battery with high SOC is charged less, and finally, the inter-pack SOC balance is realized in the charging process of the battery pack.

Sub_Pack₁Module internal battery cell B₁₁、B₁₂The SOC has larger mean deviation than the group, and closes the corresponding MOS (metal oxide semiconductor) of the switch tube_cellCell B₁₁、B₁₂Discharging redundant electric quantity to realize Sub _ Pack₁And the SOC of the battery cells in the pack is balanced. Realizing Sub _ Pack in the same way₁Sub_Pack₃And balancing the battery monomers in the module group.

And (3) discharge process equilibrium analysis: in the battery Pack discharging process, suppose that the lithium battery Sub _ Pack is detected in the kth sampling period₁Has a smaller SOC and controls each MOS_SPThe switch tube is actuated and the switch state is S₁＝0,S₂＝1,S₃When the battery Sub _ Pack is equal to 1₁Bypassing the main circuit, battery Sub _ Pack₂And Sub _ Pack₃The battery is connected to the main circuit, and the discharging current flows through the battery Sub _ Pack₂And Sub _ Pack₃Without flowing through the battery Sub _ Pack₁I.e. battery Sub _ Pack₂And Sub _ Pack₃Continuing to discharge, the battery Bat₁Stopping charging, and ensuring that the current instantaneously flows to the battery Sub _ Pack as shown in 3-2(b)₂And Sub _ Pack₃Multi-discharge, Battery Sub _ Pack₁And discharging less, and finally achieving the relative balance of the SOC of each battery. In the same way, the battery Sub _ Pack₁SOC or battery Sub _ Pack of₃When the SOC of (1) is small, the corresponding MOS is controlled_SPAnd the switch tube acts, so that the low-SOC battery discharges less, the high-SOC battery discharges more, and finally the inter-pack SOC balance is realized in the discharging process of the battery pack.

Sub_Pack₁Module internal battery cell B₁The SOC has larger mean deviation than the group, and closes the corresponding MOS (metal oxide semiconductor) of the switch tube_cellCell B₁Discharging redundant electric quantity to realize Sub _ Pack₁And the SOC of the battery cells in the pack is balanced. Realizing Sub _ Pack in the same way₁Sub_Pack₃And balancing the battery monomers in the module group.

And (3) balanced analysis of fault states: if the voltage of a certain battery is detected to be in an abnormal working condition, the MOS corresponding to the battery is immediately controlled_SPThe switch state is S_iAnd (5) 0, namely, the charging and discharging current cannot flow through the battery, the battery is in a bypass state at the moment, and other batteries continue to supply power normally, so that the fault redundancy function is realized. After the fault battery is cut off, the balance of the remaining batteries can still be realized, and the normal operation of the whole system is ensured.

It should be noted that the control methods of the present invention all belong to control strategies commonly used in the industry, and can be manually controlled, and related technical problems can be solved only by improving the topology structure.

The technical means disclosed by the scheme of the present invention is not limited to the technical means disclosed by the above embodiments, but also includes the technical scheme formed by the arbitrary combination of the above technical features. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also considered as the protection scope of the present invention.

Claims

1. The utility model provides a hybrid lithium cell voltage equalizer circuit topological structure which characterized in that: the balance module comprises a sub pack and an MOS (metal oxide semiconductor) tube group connected with the sub pack in parallel, the sub pack is formed by connecting a plurality of lithium batteries in series, the MOS tube group comprises two pairs of MOS tubes connected in anti-series, each lithium battery in the sub pack is connected with a discharge resistor and a switch in parallel, and the discharge resistor is connected with the switch in series.

2. The hybrid lithium battery voltage equalization circuit topology of claim 1, wherein: the SubPack in one equalization module comprises 12-14 lithium batteries.

3. The hybrid lithium battery voltage equalization circuit topology of claim 1, wherein: the switch is an MOS tube.