A Novel Charging Control for D-EPC with DC Power Sources Connected in Series

A new multiple DC-inputs direct electric-power converter (D-EPC) has been proposed. It can be applied to motor drive systems with two DC power sources. D-EPC has realized the charging of a DC power source with motoring by another DC power source. This charging is controlled by the voltage command multiplied by power distribution ratio more than 1.0 for the DC power source suppling power to the motor and another DC power source. If the charging power is required in the condition of voltage saturation, the voltage command for charging could be increased more than the voltage limit. This paper proposes a new charging control for D-EPC by controlling switches on the free wheel current path. This proposed control does not exceed 1.0 of the distribution ratio. The simulation results show one DC power source can be charged with motoring by another DC power source using proposed charging control.