直流微网双向DC/DC变换器的电容电荷平衡控制策略

Control Strategy for Capacitor Charge Balance of Bidirectional DC/DC Converters in the DC Micro-grid

由微源和负载等的功率波动引起的直流母线电压波动,成为影响直流微网电能质量的重要因素。通过双向DC/DC变换器连接超级电容等储能设备,可进行功率平衡调节,以保证直流微网母线电压的稳定。为实现直流微网母线电压的快速恢复,采用了一种基于电容电荷平衡控制的复合控制策略,并推导出一系列理论方程来设计相应的复合控制器。最后通过PSIM仿真验证了复合控制策略的快速性和有效性。

DC bus voltage variation caused by power fluctuation such as micro-source and load becomes a major factor affecting the power quality of DC micro-grid. Connection of super-capacitor and other energy storage devices through bidirectional DC/DC converters could realize power balance regulation and ensure the stability of bus voltage of the DC micro-grid. In order to achieve rapid recovery of DC micro-grid bus voltage, a composite control strategy was adopted on the basis of capacitor charge balance control in this paper, and a series of theoretical equations were derived for the design of corresponding composite controllers. Finally, PSIM simulation verified the rapidity and effectiveness of the proposed composite control strategy.