阅读说明：本技术 一种动力电池组主动均衡控制系统 (Active equalization control system of power battery pack ) 是由 黄正军 徐建军 渠珍珍 于 2020-04-07 设计创作，主要内容包括：本发明公开了一种动力电池组主动均衡控制系统,包括动力电池组、信息采集模块、主控模块、DC/DC模块、过流保护模块、均衡控制模块和均衡电路模块；信息采集模块的一端与动力电池组中各单体电池连接,另一端与主控模块连接；均衡控制模块的输入端与主控模块连接,驱动端通过均衡电路模块与动力电池组连接；均衡电路模块包括多组模拟电子开关和整流二极管串联组成的开关网络,开关管通过整流二极管连接到串联电池组的每一个节点处。本发明以电感为储能元件,由MOS开关管决定能量传递方向,能实现电池组内任意两节电池间能量的传递,避免多余充放电造成的能量损耗,能够达到快速、高效均衡动力电池组的目的。(The invention discloses an active equalization control system of a power battery pack, which comprises the power battery pack, an information acquisition module, a main control module, a DC/DC module, an overcurrent protection module, an equalization control module and an equalization circuit module, wherein the main control module is connected with the DC/DC module; one end of the information acquisition module is connected with each single battery in the power battery pack, and the other end of the information acquisition module is connected with the main control module; the input end of the balance control module is connected with the main control module, and the drive end of the balance control module is connected with the power battery pack through the balance circuit module; the equalization circuit module comprises a switch network formed by connecting a plurality of groups of analog electronic switches and rectifier diodes in series, and the switch tube is connected to each node of the series battery pack through the rectifier diodes. The invention takes the inductor as an energy storage element, and the MOS switch tube determines the energy transfer direction, thereby realizing the energy transfer between any two batteries in the battery pack, avoiding the energy loss caused by redundant charge and discharge, and achieving the purpose of quickly and efficiently balancing the power battery pack.)

1. An active equalization control system for a power battery pack, comprising: the device comprises a power battery pack, an information acquisition module, a main control module, a DC/DC module, an overcurrent protection module, a balance control module and a balance circuit module;

the power battery pack is formed by connecting n batteries in series;

one end of the information acquisition module is connected with each single battery in the power battery pack, and the other end of the information acquisition module is connected with the main control module, so that the acquisition of voltage analog values of the single batteries is mainly completed, and then the digital values are obtained through the conversion of an AD converter;

the processor of the main control module adopts a DSP arithmetic unit, and a battery pack formed by connecting n batteries in series can acquire n paths of AD values and output 2(n +1) paths of PWM control signals, and mainly completes the work of AD conversion, SOC estimation, external communication, PWM control signal output and the like of voltage signals of the single batteries;

the high-voltage input end of the DC/DC module is connected with the positive electrode and the negative electrode of the power battery pack, and the low-voltage output end of the DC/DC module is connected with a low-voltage electrical system of the vehicle to supply power for the DSP, the detection chip and the like;

the overcurrent protection module consists of a sampling part and a control part, the sampling resistor collects balanced current, and the balanced loop is disconnected when the current exceeds a set limit value;

the input end of the balance control module is connected with the main control module, and the drive end of the balance control module is connected with the power battery pack through the balance circuit module;

the equalizing circuit module comprises a switch network formed by connecting a plurality of groups of analog electronic switches and rectifier diodes in series, 2(n +1) MOS (metal oxide semiconductor) switch tubes and 2(n +1) rectifier diodes are needed for a battery pack formed by connecting n batteries in series, the switch tubes are connected to each node of the battery pack in series through the rectifier diodes, and the equalizing circuit module further comprises an energy storage inductor L1 and an overcurrent sampling resistor R1.

2. The power battery pack active equalization control system of claim 1, wherein the power battery pack is a lithium ion battery pack.

3. The active equalization control system of power battery pack according to claim 1, wherein an inductor is used as an energy storage element, and an MOS switching tube determines the energy transfer direction, so that the energy transfer between any two batteries in the battery pack can be realized.

Technical Field

The invention relates to an active equalization control system of a power battery pack, and belongs to the technical field of battery management.

Background

The power battery technology becomes a hot spot of domestic and foreign research as a key technology for the development of the electric automobile industry. As a core component of an electric vehicle, a power battery is acknowledged as the biggest bottleneck restricting the industrialization of new energy vehicles at present, and one of the main reasons is the inconsistency of single batteries when the batteries are used in a group, so that the comprehensive performance of a battery pack is reduced, the battery pack is used in an overrun way, and the safety and the service life of the battery pack are seriously influenced. Therefore, the problem of inconsistency of the battery pack in use is solved, and the battery pack is subjected to balanced management and control, which is very important.

The battery equalization management technology is used as a key technology of the battery management technology, and the battery characteristics of the battery pack can finally reach a consistency state by effectively performing equalization management on the battery pack. At present, battery equalization management schemes are mainly divided into two categories, namely energy dissipation type equalization and energy non-dissipation type equalization. The energy dissipation type balance is represented by a resistance balance method, and has the advantages of simple structure, high circuit reliability and the disadvantages of large energy loss, low efficiency and large temperature rise, and does not accord with the energy-saving and environment-friendly concept of new energy automobiles. The non-energy dissipation type equalization transfers energy from a high-energy cell in the battery pack to a low-energy cell or battery pack through the energy transfer function, realizes the energy transfer effect, and is the mainstream of the future development of the battery equalization technology.

At present, the domestic battery equalization management technology is still in a lagging state, the existing equalization technology has various defects, and the equalization method which is relatively simple in circuit and good in equalization effect is designed to greatly promote the development of BMS and the industrialization of power batteries.

Disclosure of Invention

The invention aims to solve the problems of complex structure, high energy consumption, complex control logic, low balancing efficiency and the like in the prior art, and provides an active balancing control system of a power battery pack, which has a simple structure, low energy consumption and a good balancing effect, so as to solve the problems of overcharge and overdischarge of any single body in the use process of the battery pack and prolong the service life of the whole battery pack.

In order to solve the above technical problem, the present invention provides an active equalization control system for a power battery pack, comprising: the device comprises a power battery pack, an information acquisition module, a main control module, a DC/DC module, an overcurrent protection module, a balance control module and a balance circuit module;

the power battery pack is formed by connecting n batteries in series;

one end of the information acquisition module is connected with each single battery in the power battery pack, and the other end of the information acquisition module is connected with the main control module, so that the acquisition of voltage analog values of the single batteries is mainly completed, and then the digital values are obtained through the conversion of an AD converter;

the processor of the main control module adopts a DSP arithmetic unit, and a battery pack formed by connecting n batteries in series can acquire n paths of AD values and output 2(n +1) paths of PWM control signals, and mainly completes the work of AD conversion, SOC estimation, external communication, PWM control signal output and the like of voltage signals of the single batteries;

the high-voltage input end of the DC/DC module is connected with the positive electrode and the negative electrode of the power battery pack, and the low-voltage output end of the DC/DC module is connected with a low-voltage electrical system of the vehicle to supply power for the DSP, the detection chip and the like;

the overcurrent protection module consists of a sampling part and a control part, the sampling resistor collects balanced current, and the balanced loop is disconnected when the current exceeds a set limit value;

the input end of the balance control module is connected with the main control module, and the drive end of the balance control module is connected with the power battery pack through the balance circuit module;

the equalizing circuit module comprises a switch network formed by connecting a plurality of groups of analog electronic switches and rectifier diodes in series, 2(n +1) MOS (metal oxide semiconductor) switch tubes and 2(n +1) rectifier diodes are needed for a battery pack formed by connecting n batteries in series, the switch tubes are connected to each node of the battery pack in series through the rectifier diodes, and the equalizing circuit module further comprises an energy storage inductor L1 and an overcurrent sampling resistor R1.

Further, in order to enable the power battery pack to store higher energy and have longer service life, the power battery pack is a lithium ion battery pack.

The invention has the beneficial effects that:

the active equalization control system of the power battery pack is energy non-dissipation type, the inductor is used as an energy storage element, the MOS switching tube determines the energy transfer direction, the energy transfer between any two batteries in the battery pack can be realized, the energy loss caused by redundant charge and discharge is avoided, and the purpose of quickly and efficiently equalizing the power battery pack can be achieved.

Drawings

The invention is further described with reference to the accompanying drawings in which:

FIG. 1 is a schematic structural diagram of an active equalization control system of a power battery pack according to the present invention;

fig. 2 is a schematic structural diagram of an equalizing circuit module according to an embodiment of the present invention.

Detailed Description

The invention will be further described by way of example with reference to the accompanying drawings.

As shown in fig. 1, the present embodiment discloses an active equalization control system for a power battery pack, including: the power battery pack 10, the information acquisition module 20, the main control module 30, the DC/DC module 40, the overcurrent protection module 50, the balance control module 60 and the balance circuit module 70;

the power battery pack 10 is formed by connecting n batteries in series;

one end of the information acquisition module 20 is connected with each single battery in the power battery pack 10, and the other end is connected with the main control module 30, so that the acquisition of the voltage analog value of each single battery is mainly completed, and then the digital value is obtained through the conversion of an AD converter;

a processor of the main control module 30 selects a DSP arithmetic unit, and a battery pack formed by connecting n batteries in series can acquire n paths of AD values and output 2(n +1) paths of PWM control signals, and mainly completes the work of AD conversion, SOC estimation, external communication, PWM control signal output and the like of voltage signals of single batteries;

the high-voltage input end of the DC/DC module 40 is connected with the positive and negative electrodes of the power battery pack 10, and the low-voltage output end is connected with a low-voltage electrical system of the vehicle to supply power for a DSP (digital signal processor), a detection chip and the like;

the overcurrent protection module 50 consists of a sampling part and a control part, a sampling resistor collects balanced current, and the balanced loop is disconnected when the current exceeds a set limit value;

the input end of the balance control module 60 is connected with the main control module 30, and the driving end is connected with the power battery pack 10 through the balance circuit module 70;

the equalizing circuit module 70 includes a switch network formed by connecting a plurality of groups of analog electronic switches and rectifier diodes in series, 2(n +1) MOS switch tubes and 2(n +1) rectifier diodes are required for a battery pack formed by connecting n batteries in series, the switch tubes are connected to each node of the series battery pack 10 through the rectifier diodes, and the equalizing circuit module further includes an energy storage inductor L1 and an overcurrent sampling resistor R1.

Further, in order to enable the power battery pack to store higher energy and have longer service life, the power battery pack is a lithium ion battery pack.

In the present embodiment, as shown in fig. 2, a power battery pack having 4 batteries connected in series is taken as an example, and the structure of the equalizing circuit module 70 is described as follows:

the battery pack comprises 4 batteries connected in series, wherein the 4 batteries are respectively B1, B2, B3 and B4, a capacitor C1 … C4 is connected with each single battery in parallel, M11, M12, … M51 and M52 are 5 pairs of MOS (metal oxide semiconductor) switching tubes, D11, D12, … D51 and D52 are 5 pairs of rectifying diodes, the MOS switching tubes and the rectifying diodes are connected in series and then are connected to positive and negative nodes of the batteries in pairs respectively, L1 is an energy storage inductor, and R1 is a balanced overcurrent sampling resistor.

With reference to fig. 2, the principle of the equalizing operation performed by the equalizing circuit module of the present invention is described as follows:

when the main control module 30 detects that the energy of the battery B1 is higher than the energy of the battery B3, a control signal is output to the equalization control module 60, the equalization control module 60 outputs a corresponding PWM modulation signal to control the simultaneous opening of the positive node MOS switch M11 and the negative node MOS switch M22 of the battery B1, the battery B1 releases energy, the energy is stored in the inductor L1, after a set time, the positive node MOS switch M11 and the negative node MOS switch M22 of the battery B1 are closed, the positive node MOS switch M32 and the negative node MOS switch M41 of the battery B3 are opened simultaneously, and the energy in the inductor is transferred to the battery B3, so that the energy is transferred from the battery B1 to the battery B3. During the equalization process, the overcurrent protection module 50 detects the equalization current, when the equalization current exceeds a preset value, a signal is fed back to the main control module 30, and the equalization control module 60 adjusts the frequency and duty ratio of the output PWM control signal, so as to ensure the safety of the equalization process until the equalization is finished.

In the process, the battery B1 and the battery B3 can be single batteries or multiple batteries connected in series, the on-off of different MOS switching tubes is controlled, and energy transfer can be realized between any single battery and the single battery, between the single battery and multiple batteries connected in series, between the multiple batteries connected in series and multiple batteries connected in series in the battery pack.