基于可切换电感的站用直流电源双向CLLLC研究

Research on Bidirectional CLLLC Resonant Converter of DC Auxiliary Power Supply System Based on Switchable Inductance

摘要:

站用直流系统中锂离子电池长时满容量备电会导致谐振变换器调频在轻载时调频范围过宽、低电压增益控制难以实现等问题。而基于双向电容-电感-电感-电感-电容拓扑结构(capacitor-inductor-inductor-inductor-capacitor, CLLLC)的变换器能实现母线与储能系统间的高效功率转换，具有较高的电压增益范围。为此，提出了一种基于可切换电感的CLLLC谐振变换器方案及其控制策略。首先，根据CLLLC的基本原理设计可切换电感等谐振参数并构建电路拓扑；其次，提出了基于谐振电流内环的双环策略控制策略；最后，通过Matlab/Simulink仿真验证了所提方案在锂离子电池储能系统中的有效性。

Abstract:

The long-term full-capacity standby power supply of lithium-ion batteries in DC auxiliary power system can lead to an excessively wide frequency modulation range for resonant converters under light loads and the difficulties in achieving low-voltage gain control. The converter based on bidirectional capacitor-inductor-inductor-inductor-capacitor (CLLLC) topology can achieve efficient power conversion between the bus and the energy storage system, offering a high voltage gain range. So, a design method and control strategy for CLLLC resonant converter based on switchable inductance is proposed. Firstly, according to the operating principles of CLLLC converter, the resonant parameters, including switchable inductance, are designed for different load conditions, and the circuit topology is constructed. Secondly, a dual-loop control strategy with an inner loop based on resonant current is proposed. Finally, the effectiveness of the proposed solution for lithium-ion battery energy storage systems is verified through the Matlab/Simulink platform.