CN101814759A

CN101814759A - Energy balance control device and energy balance control method of battery pack

Info

Publication number: CN101814759A
Application number: CN 201010167667
Authority: CN
Inventors: 冯大明; 刘飞; 阮旭松; 张维戈; 王占国; 文锋
Original assignee: Huizhou Epower Electronics Co Ltd; Beijing Jiaotong University
Current assignee: Huizhou Epower Electronics Co Ltd; Beijing Jiaotong University
Priority date: 2010-05-06
Filing date: 2010-05-06
Publication date: 2010-08-25

Abstract

The present invention relates to the field of battery pack balance control, in particular to a battery pack balance control device and a balance control method. The device is used to control the balance of a battery pack composed of more than one battery in series. The device includes: A judging module for judging whether the battery pack needs to be balanced; a balancing module for balancing the battery pack; the battery pack and the judging module are respectively connected to the balancing module; the judging module is connected to the balancing module to control whether the balancing module performs battery balancing, The judging module controls whether the balancing module balances the batteries according to the monitored energy utilization rate of the battery pack. The invention adopts the energy utilization rate of the battery pack as the quantitative evaluation standard for judging the consistency of the battery pack, monitors the energy utilization rate of the battery pack, monitors the consistency of the battery pack in real time, and can accurately balance the batteries of the battery pack, thereby improving the energy efficiency of the battery pack. utilization and extend battery life.

Description

A battery pack energy balance control device and energy balance control method

技术领域technical field

本发明涉及电池组均衡控制领域，特别是一种电池组均衡控制装置及均衡控制方法。The invention relates to the field of battery pack balance control, in particular to a battery pack balance control device and a balance control method.

技术背景technical background

为了达到一定的电压、功率和能量等级，电池需要串联成组使用，如电动汽车、储能系统、直流系统等。然而，由于生产和使用过程中不可能做到完全一致，所以电池之间的一致性是相对的，不一致是绝对的。由于容量小、内阻大、自放电率高的电池在充放电过程中更容易发生过充电、过放电和过热，导致电池性能下降速度加快，呈现“正反馈”，这导致电池组一致性问题被加速放大。由于电池的应用技术涉及电化学、电学和热学相关知识，对电池性能的评价和维护方法难度较大。在实际使用时，为了给电池的均衡和维护提供数据支持，需要对电池组一致性进行量化评价，从而确定是否需要对电池组进行电池均衡。现有技术对于如何判断是否需要对电池组进行电池均衡的方法不够精确，从而导致在不适当的条件下对电池组进行电池均衡，效率低下同时也减少了电池的寿命。In order to achieve a certain voltage, power and energy level, batteries need to be used in series in groups, such as electric vehicles, energy storage systems, DC systems, etc. However, since it is impossible to achieve complete consistency during production and use, the consistency between batteries is relative, and the inconsistency is absolute. Batteries with small capacity, large internal resistance, and high self-discharge rate are more likely to be overcharged, overdischarged, and overheated during charging and discharging, resulting in faster battery performance degradation and a "positive feedback", which leads to battery consistency problems is accelerated and magnified. Since the application technology of the battery involves the knowledge of electrochemistry, electricity and heat, it is difficult to evaluate and maintain the battery performance. In actual use, in order to provide data support for battery balancing and maintenance, it is necessary to quantitatively evaluate the consistency of the battery pack to determine whether battery balancing is required for the battery pack. In the prior art, the method for judging whether to perform cell equalization on the battery pack is not accurate enough, which leads to performing cell equalization on the battery pack under inappropriate conditions, resulting in low efficiency and shortened battery life.

发明内容Contents of the invention

本发明提供一种电池组均衡控制装置以解决现有技术中对电池组进行电池均衡不精确的技术问题。The invention provides a battery pack balance control device to solve the technical problem of inaccurate battery balance in the prior art.

本发明的另外一个发明目的在于提出一种应用该控制装置的控制方法。Another object of the present invention is to provide a control method using the control device.

本发明的第一个发明目的采用的技术方案如下：The technical scheme adopted by the first object of the invention of the present invention is as follows:

一种电池组均衡控制装置，所述装置用于控制对由多于一个电池串联组成的电池组进行均衡，所述装置包括：A battery pack balance control device, the device is used to control the balance of a battery pack composed of more than one battery connected in series, the device includes:

用于判断电池组是否需要进行均衡的判断模块；A judging module for judging whether the battery pack needs to be balanced;

用于对电池组进行均衡的均衡模块；A balancing module for balancing the battery pack;

电池组与判断模块，均衡模块分别连接；The battery pack is connected to the judging module and the balancing module respectively;

判断模块与均衡模块连接，用于控制均衡模块是否进行电池均衡，所述判断模块根据监测电池组的能量利用率，控制均衡模块是否对电池进行均衡。The judging module is connected with the balancing module, and is used to control whether the balancing module performs battery balancing, and the judging module controls whether the balancing module performs battery balancing according to monitoring the energy utilization rate of the battery pack.

本发明的第二个发明目的采用的技术方案如下：The technical scheme that the second object of the invention of the present invention adopts is as follows:

一种电池组均衡控制方法，所述方法包括：A battery pack balancing control method, the method comprising:

(21)通过所述判断模块监测电池组的能量利用率，当电池组的能量利用率低于预先设定的阈值则执行步骤(22)，否则执行步骤(21)；(21) Monitoring the energy utilization rate of the battery pack by the judging module, when the energy utilization rate of the battery pack is lower than a preset threshold, step (22) is executed, otherwise step (21) is executed;

(22)均衡模块对电池组进行电池均衡，执行步骤(21)。(22) The balance module performs battery balance on the battery pack, and performs step (21).

作为一种优选方案，所述步骤(21)的判断模块的具体步骤为：As a preferred solution, the specific steps of the judging module of the step (21) are:

(31)监测电池组的充放电过程，测量单只电池的最大可用容量和SOC；(31) Monitor the charging and discharging process of the battery pack, and measure the maximum available capacity and SOC of a single battery;

(32)记录当前状态下电池组最大可用能量和均衡状态下的电池组最大可用能量；(32) Record the maximum available energy of the battery pack under the current state and the maximum available energy of the battery pack under the balanced state;

(33)记录电池组的能量利用率＝当前状态下的电池组最大可用能量/均衡状态下的电池组最大可用能量；(33) Record the energy utilization rate of the battery pack=the maximum available energy of the battery pack under the current state/the maximum available energy of the battery pack under the balanced state;

(34)如果电池组的能量利用率低于预先设定的阈值则执行步骤(22)均衡模块对电池组进行电池均衡，否则执行步骤(31)。(34) If the energy utilization rate of the battery pack is lower than the preset threshold, execute step (22) the balancing module performs battery balancing on the battery pack, otherwise execute step (31).

其中步骤(31)仅需要在电池组工作前测量一次即可。The step (31) only needs to be measured once before the battery pack works.

作为一种优选方案，所述步骤(21)的判断模块监测由n个电池串联而成的电池组的能量利用率的方法为：As a preferred solution, the method for the judging module of the step (21) to monitor the energy utilization rate of the battery pack formed by n batteries connected in series is:

(41)计算电池组的最大放电容量

最大充电容量

和最大可用容量

(41) Calculate the maximum discharge capacity of the battery pack

Maximum charging capacity

and maximum usable capacity

(42)计算在电池组全充全放的过程中，单只电池的SOC工作区间[SOC_{dch_end}，SOC_{ch_end}]；(42) Calculate the SOC working range [SOC _{dch_end} , SOC _{ch_end} ] of a single battery during the process of fully charging and fully discharging the battery pack;

(43)计算电池组在当前状态下的最大可用能量

和均衡后的最大可用能量

(43) Calculate the maximum available energy of the battery pack in the current state

and the maximum available energy after equilibrium

(44)计算电池组的能量利用率

(44) Calculate the energy utilization rate of the battery pack

(45)当

低于预先设定的阈值则执行步骤(22)调用均衡模块对电池组进行电池均衡，否则执行步骤(41)。(45) when

If it is lower than the preset threshold, then step (22) is executed to call the balancing module to perform battery balancing on the battery pack; otherwise, step (41) is executed.

本发明采用电池组能量利用率作为判断电池组一致性的量化评价标准，通过对电池组能量利用率进行监测，实时监测电池组的一致性，能精确的对电池组进行电池均衡，从而提高电池组能量利用率，延长电池寿命。The present invention adopts the energy utilization rate of the battery pack as the quantitative evaluation standard for judging the consistency of the battery pack. By monitoring the energy utilization rate of the battery pack, the consistency of the battery pack can be monitored in real time, and the battery pack can be accurately balanced, thereby improving the efficiency of the battery pack. Improve group energy utilization and extend battery life.

附图说明Description of drawings

图1为本发明的工作流程。Fig. 1 is the workflow of the present invention.

具体实施方式Detailed ways

下面结合附图和具体实施例对本发明进行进一步详细的说明。The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

1电池组的最大可用能量1 The maximum available energy of the battery pack

n只最大可用容量分别为Q_max[1]，...，Q_max[n]，荷电状态分别为SOC₀[1]，...，SOC₀[n]的电池串联成组后，电池组的主要参数如下：After n batteries with the maximum available capacity of Q _max [1], ..., Q _max [n] and the states of charge of SOC ₀ [1], ..., SOC ₀ [n] are connected in series, The main parameters of the battery pack are as follows:

(1)最大放电容量

其中i＝1，...，n；(1) Maximum discharge capacity

where i=1,...,n;

(2)最大充电容量

其中j＝1，...，n；(2) Maximum charging capacity

where j=1,...,n;

(3)最大可用容量

(3) Maximum available capacity

(4)最大可用能量

其中m＝1，...，n。(4) Maximum available energy

where m=1, . . . , n.

${SOC SOC}_{dch dch__end end} [[m m]] = = {SOC SOC}_{00} [[m m]] - - \frac{{Q Q}_{rem rem}^{B B}}{{Q Q}_{max max} [[m m]]},,$ ${SOC SOC}_{ch ch__end end} [[m m]] = = {SOC SOC}_{00} [[m m]] + + \frac{{Q Q}_{ch ch__max max}^{B B}}{{Q Q}_{max max} [[m m]]} . .$

可见，串联成组后，电池组的最大可用能量与组内个单只电池的最大可用容量以及所处SOC有关。为了实现电池组能量利用的最大化，一方面需要电池组的容量充分利用；另一方面，每只电池都处于更高的SOC对于提高电池组的存储能量同样具有重要的意义。也就是说，为了实现存储能量达到最大化，电池组的均衡不仅需要实现容量最小电池的充满电和放完电(即电池的容量达到充分利用)，还要使得电池组中所有电池的荷电状态达到尽可能高，即在充电结束时保证所有电池都充满电，这是从能量的角度而言电池组是否需要进行均衡的判断依据。It can be seen that after being connected in series, the maximum available energy of the battery pack is related to the maximum available capacity of a single battery in the pack and its SOC. In order to maximize the energy utilization of the battery pack, on the one hand, the capacity of the battery pack needs to be fully utilized; on the other hand, a higher SOC of each battery is also of great significance for improving the storage energy of the battery pack. That is to say, in order to maximize the storage energy, the balance of the battery pack not only needs to realize the full charge and discharge of the battery with the smallest capacity (that is, the capacity of the battery is fully utilized), but also makes the charge of all the batteries in the battery pack The state is as high as possible, that is, to ensure that all batteries are fully charged at the end of charging, which is the basis for judging whether the battery pack needs to be balanced from an energy point of view.

2电池组的能量利用率2 Energy utilization of the battery pack

假设电池p为n只电池串联组成的电池组中容量最小的电池，则电池组充满电时，组内所有单只电池都被充满电，即所有单只电池的SOC都达到100％。当对电池组进行放电时，电池组的最大放电容量就是其均衡后的最大可用容量

等于电池p的最大可用容量(Q_max[p])，即：Assuming that battery p is the battery with the smallest capacity in a battery pack composed of n batteries connected in series, when the battery pack is fully charged, all single batteries in the pack are fully charged, that is, the SOC of all single batteries reaches 100%. When discharging the battery pack, the maximum discharge capacity of the battery pack is the maximum available capacity after equalization

Equal to the maximum usable capacity of battery p (Q _max [p]), that is:

${Q Q}_{max max}^{eq eq__B B} = = {Q Q}_{max max} [[p p]] \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((11))$

所以放电结束时，电池组中任意电池m的剩余容量

为：Therefore, at the end of discharge, the remaining capacity of any battery m in the battery pack

for:

${Q Q}_{dch dch__end end}^{eq eq} [[m m]] = = {Q Q}_{max max} [[m m]] - - {Q Q}_{max max} [[p p]] \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot \cdot \cdot \cdot \cdot ((22))$

此时，该电池的荷电状态

为：At this time, the state of charge of the battery

for:

${SOC SOC}_{dch dch__end end}^{eq eq} [[m m]] = = \frac{{Q Q}_{max max} [[m m]] - - {Q Q}_{max max} [[p p]]}{{Q Q}_{max max} [[m m]]} \times \times 100100 % % = = \frac{{Q Q}_{max max} [[m m]] - - {Q Q}_{max max}^{eq eq__B B}}{{Q Q}_{max max} [[m m]]} \times \times 100100 % % \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((33))$

所以在充放电过程中，电池m的最大可用能量

为：Therefore, during the charging and discharging process, the maximum available energy of the battery m

for:

${E E.}_{max max}^{eq eq} [[m m]] = = {Q Q}_{max max}^{eq eq__B B} \times \times {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end}^{eq eq} [[m m]],, 100100 % %]]} \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdot ((44))$

电池组的最大可用能量

为：The maximum available energy of the battery pack

for:

$E_{\max}^{eq_B} = Q_{\max}^{eq_B} \times Σ_{k = 1}^{n} U_{SOC = [{SOC}_{dch_end}^{eq} [k], 100 %]},$ k＝1，...，n.....................(5) ${E.}_{\max}^{eq_B} = Q_{\max}^{eq_B} \times Σ_{k = 1}^{no} u_{SOC = [{SOC}_{dch_end}^{eq} [k], 100 %]},$ k=1,...,n...................(5)

所以电池的能量利用率为：Therefore, the energy utilization rate of the battery for:

${η η}_{E E.}^{B B} = = \frac{{E E.}_{max max}^{B B}}{{E E.}_{max max}^{eq eq__B B}} = = \frac{{Q Q}_{max max}^{B B} \times \times {Σ Σ}_{m m = = 11}^{n no} {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end} [[m m]],, {SOC SOC}_{ch ch__end end} [[m m]]]]}}{{Q Q}_{max max}^{eq eq__B B} \times \times {Σ Σ}_{k k = = 11}^{n no} {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end}^{eq eq} [[k k]],, 100100 % %]]}}$

$= = {η η}_{C C}^{B B} \times \times \frac{{Σ Σ}_{m m = = 11}^{n no} {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end} [[m m]],, {SOC SOC}_{ch ch__end end} [[m m]]]]}}{{Σ Σ}_{k k = = 11}^{n no} {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end}^{eq eq} [[k k]],, 100100 % %]]}} \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((66))$

由于均衡后，对于任意一只电池，都有：After equalization, for any battery, there are:

${Q Q}_{max max}^{eq eq__B B} \times \times {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end}^{eq eq} [[k k]],, 100100 % %]]} &GreaterEqual; &Greater Equal; {Q Q}_{max max}^{B B} \times \times {U u}_{SOC SOC = = [[{SOC SOC}_{dch dch__end end} [[k k]],, {SOC SOC}_{ch ch__end end} [[k k]]]]} \cdot \cdot \cdot \cdot \cdot \cdot \cdot &Center Dot; \cdot &Center Dot; \cdot \cdot ((77))$

所以

总是小于等于1，这样在使用的过程中，电池组的一致性越差，

就越小，因此电池组的能量利用率是电池组一致性的量化评价指标和是否需要均衡的判断依据。so

It is always less than or equal to 1, so that in the process of use, the consistency of the battery pack is worse,

Therefore, the energy utilization rate of the battery pack is the quantitative evaluation index of the consistency of the battery pack and the basis for judging whether it needs to be balanced.

如图1所示，本发明的具体工作流程如下：As shown in Figure 1, the specific workflow of the present invention is as follows:

(S1)计算电池组的最大放电容量最大充电容量

和最大可用容量

(S1) Calculate the maximum discharge capacity of the battery pack Maximum charging capacity

and maximum usable capacity

(S2)计算在电池组全充全放的过程中，单只电池的SOC工作区间[SOC_{dch_end}，SOC_{ch_end}]；(S2) Calculate the SOC working range [SOC _{dch_end} , SOC _{ch_end} ] of a single battery during the process of fully charging and fully discharging the battery pack;

(S3)计算电池组在当前状态下的最大可用能量

和均衡后的最大可用能量

(S3) Calculate the maximum available energy of the battery pack in the current state

and the maximum available energy after equilibrium

(S4)计算电池组的能量利用率

(S4) Calculate the energy utilization rate of the battery pack

(S5)当

低于预先设定的阈值则执行步骤(S6)调用均衡模块对电池组进行电池均衡，否则执行步骤(S1)；(S5) when

If it is lower than the preset threshold, step (S6) is executed to call the balancing module to perform battery balancing on the battery pack, otherwise step (S1) is executed;

(S6)调用均衡模块对电池组进行电池均衡。(S6) Calling the balance module to perform battery balance on the battery pack.

Claims

1. one kind is utilized maximized battery pack balancing control device based on energy, and described device is used for carrying out equilibrium more than the battery pack of a battery series connection, and described device comprises:

Be used to judge whether battery pack needs to carry out balanced judge module;

Be used for battery pack is carried out balanced balance module;

Battery pack is connected with balance module respectively with judge module;

Whether judge module is connected with balance module, be used to control balance module and carry out battery balancedly, it is characterized in that: described judge module is according to the capacity usage ratio of monitoring battery pack, and whether the control balance module carries out equilibrium to battery.

2. one kind is utilized maximized battery pack balancing control method based on energy, adopts the described device of claim 1, it is characterized in that described method comprises:

(21) capacity usage ratio by described judge module monitoring battery pack, when the capacity usage ratio of battery pack is lower than then execution in step (22) of pre-set threshold, otherwise execution in step (21);

(22) balance module battery pack is carried out battery balanced, execution in step (21).

3. balance control method according to claim 2 is characterized in that, the concrete steps of the judge module of described step (21) are:

(31) charge and discharge process of monitoring battery pack, the maximum available and the SOC of single battery of measurement;

(32) the battery pack maximum available energy under battery pack maximum available energy and the equilibrium state under the record current state;

(33) the battery pack maximum available energy under the battery pack maximum available energy/equilibrium state under the capacity usage ratio=current state of record battery pack;

(34) if the capacity usage ratio of battery pack is lower than pre-set threshold execution in step (22) balance module battery pack is carried out battery balanced, otherwise execution in step (31).

4. balance control method according to claim 2 is characterized in that, the method that the judge module of described step (21) is monitored the capacity usage ratio of the battery pack that is in series by n battery is:

(41) maximum discharge capacity of counting cell group

, the maximum charge capacity

And maximum available

(42) the SOC operation interval [SOC of single battery is filled in the process of putting entirely in calculating entirely in battery pack _{Dch_end}, SOC _{Ch_end}];

(43) maximum available energy of counting cell group under current state

With the maximum available energy after the equilibrium

(44) capacity usage ratio of counting cell group

(45) when

Be lower than pre-set threshold then execution in step (22) call balance module battery pack is carried out battery balanced, otherwise execution in step (41).