Oscillation Suppression Method for a DC Power Supply System with a Constant Power Load and LC Filter

Abstract

In a DC power supply system with a constant power load (CPL) and LC filter, the input voltage may oscillate because of the interaction between the output impedance of the LC filter and input negative impedance of the CPL. This paper proposes a control method for the oscillation that uses a bidirectional DC-DC chopper and a power storage capacitor in order to reduce the energy loss for oscillation suppression. In the method, the four variables of voltages and currents in the LC filter and bidirectional DC-DC chopper are feedbacked to suppress the oscillation. To reduce the number of sensors, the minimum order state observer was adopted. The effectiveness of the proposed method was demonstrated in both simulations and experiments.