PUBLICATIONS

This paper proposes an output current ripple reduction algorithm using a proportional-integral (PI) controller for an energy storage

system (ESS). In single-phase systems, the DC/AC inverter has a second-order harmonic at twice the grid frequency of a DC-link

voltage caused by pulsation of the DC-link voltage. The output current of a DC/DC converter has a ripple component because of the

ripple of the DC-link voltage. The second-order harmonic adversely affects the battery lifetime. The proposed algorithm has an

advantage of reducing the second-order harmonic of the output current in the variable frequency system. The proposed algorithm

is verified from the PSIM simulation and experiment with the 3 kW ESS model.