Topology for current balancer with half-bridge inverters in single-phase three-wire distribution systems with DC-capacitor-voltage balancer

This paper proposes a new topology for a current balancer with half-bridge inverters in single-phase three-wire distribution systems with a three-leg inverter. Two half-bridge inverters are connected to the sources. The midpoint of two capacitors on the DC-side is connected to a neutral line. The two half-bridge inverters perform a current balancer for single-phase three-wire distribution systems by exchanging the active and reactive power on the each feeder through the two DC-capacitors. The third-leg performs a DC-capacitor-voltage balancer for the two DC-capacitors connected to the half-bridge inverters. Thus, balanced source voltages and currents are obtained on the secondary-side on the polemounted distribution transformer with balanced DC-capacitor voltages. The basic principle of the proposed current balancer is discussed in detail, and then, confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results show that balanced source voltages and currents are obtained on the secondary-side on the pole-mounted distribution transformer with balanced DC-capacitor voltages.