移相全桥变换器在直流微电网储能单元中的应用

Application of phase-shifting full-bridge converter in energy storage unit of DC microgrid

利用移相全桥变换器设计直流微电网中的储能单元,并采用蓄电池作为储能设备。首先介绍了直流微电网的结构和基于母线电压信息的系统运行模式切换方法。在分析移相全桥变换器单侧移相和双侧移相工作原理的基础上,分别设计了储能单元恒压下垂模式和恒流模式的控制策略。结合直流微电网运行模式和储能单元控制策略,进一步提出了基于母线电压信息和微电网中心控制器指令相结合的储能单元运行模式切换方案。搭建了相关实验平台,所设计的储能单元可按照母线电压信息和电流指令在恒压与恒流模式之间进行切换,实验结果验证了所提储能单元控制策略与运行模式切换方案的有效性。

The phase-shifting full-bridge converter is applied in the design of ESU（Energy Storage Unit） for DC microgrid and the batteries are adopted as its energy storage devices. The architecture of DC microgrid and the system operating mode switching based on the DC-bus voltage signal are introduced. The single- and dualside phase-shifting principles of phase-shifting full-bridge converter are analyzed and the ESU control strategies in constant-voltage droop mode and constant-current mode are designed respectively. By combining the DC microgrid operating mode with the ESU control strategy,an ESU operating mode switching scheme based on the DC-bus voltage signal together with the command of DC microgrid central controller is proposed. An experiment platform is established and the experimental results of an ESU prototype demonstrate the switching between constant-voltage and constant-current operating modes based on the DC-bus signal and current command,verifying the effectiveness of the proposed ESU control strategy and switching scheme.