An oscillation suppression method of a DC power supply system with a constant power load and a LC filter

In a DC power supply system with a constant power load (CPL) and a LC filter, the input voltage may oscillate due to an impedance interaction between output impedance of a LC filter and input negative impedance of a CPL around the operating point. This paper proposes a control method of the oscillation by using a bi-directional DC-DC converter and a power storage capacitor. In the method, the four variables of voltages and currents in the LC filter and the bi-directional DC-DC converter are used to suppress the oscillation. To reduce the number of sensors, a minimum order state observer is adopted. The effectiveness of the proposed method are illustrated by both simulations and experiments.