基于LC谐振变换器串联锂电池组控制策略研究

Research on Control Strategies Based on LC Resonant Converter for Series-Connected Battery Strings

现今LC谐振变换器中锂电池电压均衡控制策略主要有两种,分别是直接单对单均衡(DC2C)和直接多对多均衡(MC2MC),且DC2C控制简单但均衡时间长,MC2MC控制复杂但均衡时间短,所以针对LC谐振变换器的拓扑结构中串联锂离子电池在不同均衡方式下的均衡速度不一致问题,文中提出一种改进型控制策略;该控制策略结合DC2C和MC2MC这两种均衡策略的优点,使用先单后多的控制策略实现电池电压均衡,并且采用图论法分析了在改进型控制策略下的拓扑结构运行模态。文中在MATLAB/Simulink电力仿真平台上搭建了仿真模型,仿真结果表明拓扑在改进型控制策略下的均衡时间为0.191s,较DC2C的均衡时间0.335 s提升了75.4%,较MC2MC的0.22 s提升了19%,改进型控制策略在电路结构中的运行不仅合理有效,且拥有均衡速度更快,均衡时间更短的优点。

There are two voltage equalization control strategies for lithium batteries in LC resonant converters nowadays, namely direct cell-to-cell balancing (DC2C) and direct multicell-to-multicell balancing (MC2MC). And DC2C control is simple but the equalization time is long, while MC2MC control is com-plex but the equalization time is short. This paper proposes an improved control strategy to ad-dress the issue of inconsistent equalization speed of series lithium-ion batteries in the LC resonant equalizer topology under different equalization modes. This control strategy combines the control advantages of DC2C andMC2MC, using a control strategy of first order then multiple to achieve bat-tery voltage balance, and using graph theory to analyze the topology operation mode under the im-proved control strategy. This article builds a simulation model on the MATLAB/Simulink power simulation platform. The simulation results show that the equilibrium time of the topology under the improved control strategy is 0.191 s, which is 75.4% higher than the equilibrium time of 0.335 s for DC2C, and 19% higher than the 0.22 s for MC2MC. The operation of improved control strategies in circuit structures is not only reasonable and effective, but also has the advantages of faster equalization speed and shorter equalization time.