An Application of Adaptive-Capacitor-Converter in Improving the Stability of the Cascade System in DC-Microgrid

A problem about the stability of the cascade system exists in distributed power system because of the impedance characteristic curve intersection between the source converter and the load converter. In this paper, an Adaptive-Capacitor-Converter(ACC) is proposed to adjust the impedance curves with the aim of preventing intersection, which can assist the unstable cascade system to satisfy the impedance rule to make the system stable. This proposed application has these following advantages: the circuit is simple, a method of nonelectrolytic capacitor is achieved. The topology of this converter, the operation modes analysis and the control strategy are proposed. Finally the simulation result is listed to verify the correctness of the analysis and the feasibility of ACC.