Active RC Auxiliary Circuit With Parameter Switching Scheme for Stabilization and Transient Mitigation of Cascaded DC/DC Systems

Abstract

DC distribution power systems have been widely used in more electric aircraft, electric vehicles, etc. Therein, power converters in the energy source and loads are connected to the DC bus, and hence form a cascaded system. In this context, voltage oscillations due to the control interaction should be avoided in the system. In addition, the system requires a regulated bus voltage with small transient deviations. However, most existing stabilization methods including active capacitor converters cannot ensure the transient performance of the cascaded system. This paper proposes an active auxiliary circuit that can emulate passive RC circuits and switch the RC parameters in load transients and steady states, which can stabilize the cascaded system and mitigate fast load transients. The parameter design of the proposed auxiliary circuit and the stability analysis of the cascaded system with the auxiliary circuit are introduced. Simulation results are given to verify the feasibility of the proposed method.