基于电压倍增器的混合储能系统电压均衡方法

Voltage equalization method for the hybrid energy storage system based on voltage multiplier circuit

传统主动均衡拓扑往往需要大量的开关管、电感、变压器或双向开关等元件实现能量传递,对于电动汽车而言,无疑会增加系统的体积和成本。鉴于此,本文提出了一种基于电压倍增器的电压均衡拓扑,用于锂离子电池和超级电容组成的混合储能系统。电池均衡拓扑和超级电容均衡充电器通过复用半桥逆变电路集成到仅含2个开关管、3个电感以及若干电容和二极管的电路中,可有效降低混合储能系统的体积和成本。电池均衡拓扑具有自模块化特性,电压均衡速度更快,超级电容充电器具有恒流充电特性。本文详细描述了该拓扑的工作模态和波形,并利用PSIM仿真验证了其均衡特性。最后,设计了由4个电池和4个超级电容所组成的混合阵列进行实验验证。实验结果表明,均衡后单体间电压极差降至10 mV以下,证明了所提方法的有效性。

The traditional active equalization topologies often require a large number of switches,inductors,transformers or bidirectional switches to transfer energy,which undoubtedly increase the system size and cost significantly for electric vehicles.In view of this,this article proposes a voltage equalization topology based on voltage multiplier for a hybrid energy storage system consisted of lithium-ion batteries and supercapacitors.The battery equalization topology and the supercapacitor charger are integrated into a circuit containing only two switches,three inductors,and several capacitors and diodes by sharing a half-bridge inverter circuit,which can significantly reduce the size and cost of the system.The battery equalization topology has a self-modularization feature,leading to faster voltage equalization,while the supercapacitor charger has a constant current charging capability.In this article,the operation modes and waveforms are described in detail and the equalization characteristics of the proposed topology is verified by using PSIM simulation.Finally,a hybrid array consisted of 4 batteries and 4 supercapacitors was designed for experimental verification.The experimental results show that the voltage gap is reduced to less than 10 mV after equalization,proving the effectiveness of the proposed method.