L-LLC谐振型双向DC-DC变换器的复合最优轨迹控制策略研究

Research on the Hybrid Optimal Control Principle Based on the L-LLC Resonant Bidirectional DC-DC Converter

针对L-LLC谐振型双向DC-DC变换器提出了比例-积分-谐振(PID)控制与最优轨迹控制相结合的复合最优轨迹控制策略。在系统稳态时采用PID控制减小稳态误差保持输出电压恒定;当出现负载跳变时,采用最优轨迹控制改变开关管的频率,使其在最短时间内重新达到稳态。该控制策略实现了输入侧开关管的零电压开通和输出侧整流管的零电流关断,精确预测了负载突变时的开关管导通时间,显著提高了变换器的动态性能且减小了运算的复杂度。仿真和实验结果表明,采用复合最优轨迹控制策略显著改善了L-LLC谐振型双向DC-DC变换器的动态性能。

A hybrid optimal trajectory control strategy based on PID and optimal trajectory control is proposed for L-LLC resonant bidirectional DC-DC converter.PID is used to eliminate the steady state error to keep the output voltage constant during the steady state.The optimal trajectory control is used to change switching frequency when the load transients,so that it can reach steady state in the shortest time.The control strategy realizes zero voltage switching for primary-side switches and zero current switching for secondary-side rectifiers,the conduction time of switch is predicted accurate.It greatly improves the dynamic performance of the converter and reduces the complexity of operation.The simulation and experiment results show that the correctness of theoretical analysis and the superiority of dynamic performance of the hybrid optimal control principle based on the L-LLC resonant bidirectional DC-DC converter.