一种均衡电路及均衡方法研究

Research on an equalization circuit and equilibrium method

可重构均衡电路能较好地兼顾元器件使用数目,均衡转换效率,满足电池组内任意单体电池进行均衡的需求,但对电池组进行均衡时负载电压会有波动。在保留可重构均衡电路优点的前提下,较好地解决上述问题,提出带有附加电源的可重构均衡电路。在均衡过程中,通过让附加电源代替被均衡的单体电池,为负载供电,达到稳定负载电压的目的。在此基础上,文中还提出一种均衡方法,不同于将电池荷电状态(State of Charge,SOC)均衡至目标值的传统方法,通过留有一定的裕量,减少因电池容量差异,导致存在不必要均衡现象的发生次数,间接地提高均衡速度。采用此均衡电路及均衡方法对串联的8节具有不同初始SOC的18650电池进行了均衡实验,其中1节电池为附加电源。实验结果表明,所提出的均衡电路配合所提出的均衡方法,可以较好地对电池组进行均衡。

The reconfigurable equalization circuit can better balance the number of components used,balance the conversion efficiency,and meet the needs of equalization of any single cell in the battery pack,but the load voltage will fluctuate when the battery pack is equalized.In order to solve the above problems,a reconfigurable equalization circuit with additional power supply is proposed to preserve the advantages of reconfigurable equalization circuit.In the equalization process,the power supply is supplied to the load by replacing the balanced single cell with the additional power supply to stabilize the load voltage.On this basis,this paper also proposes a balanced method,which is different from the traditional method of balancing the state of charge(SOC)to the target value.The number of unnecessary balance phenomena is reduced by leaving a certain margin,and the equilibrium speed is increased indirectly.A series of equalization experiments of 18650 batteries with 8 different initial SOC in series are carried out through using this equalization circuit and equalization method,of which 1 battery is additional power sources.The experimental results show that the proposed equalization circuit can better balance the battery pack with the proposed equalization method.