高压大容量储能变流器电池组平衡控制策略

Battery pack balancing control strategy for high voltage and large capacity energy storage converter

大容量储能设备的储能单元通常由大量电池组通过串并联方式获得,由于各电池组的参数差异很难保证每个电池组按照一致的充放电曲线工作,极易造成单电池组的过充过放等现象,降低储能设备的寿命与性能。针对上述问题提出一种级联H桥储能变流器电池组平衡控制策略,解释了级联H桥储能变流器的工作原理与内部能量传递方式,通过每个电池组当前荷电状态与平均的充放电曲线来求取各个电池组工作状态与子模块电容电压指令值,配合排序算法与最近电平逼近法实现子模块电容电压稳定并令系统内N-1个电池组按照平均电曲线工作(N为H桥子模块个数),最后通过Matlab/Simulation仿真平台验证了该控制算法的可行性。

The energy storage unit of large capacity energy storage equipment is usually obtained by series-parallel connection of a large number of battery packs.It is difficult to ensure that each battery pack works according to the same charging and discharging curve because of the different parameters of each battery pack.It is very easy to cause overcharging and over discharging of single battery pack and reduce the life and performance of energy storage equipment.Aiming at the above problems,a battery pack balancing control strategy of cascaded H-bridge energy storage converter is proposed.Firstly,the working principle and internal energy transfer mode of cascaded H-bridge energy storage converter are explained.Secondly,the working state of each battery pack and the sub-module electricity are calculated by the current charge state and average charge-discharge curve of each battery pack.Capacitance voltage command value is combined with sorting algorithm and nearest level approximation method to realize the sub-module capacitance voltage stability and make N-1 battery pack work according to the average electric curve(N is the number of H-bridge modules).Finally,the feasibility of the control algorithm is verified by MATLAB/Simulation simulation platform.