A New Current Balancer for Single-Phase Three-Wire Secondary Distribution Feeders Using the Correlation Coefficients

This paper proposes a new current balancer for single-phase three-wire distribution feeders using a three-leg voltage-source PWM inverter, which is equivalent to a three-phase voltage source inverter. Intelligent power modules (IPMs) can be used for the proposed current balancer. Thus we can provide a cost-effective and small-volume current balancer. A new control method for the proposed current balancer employing correlation coefficients between the source voltage and load currents is also proposed. The basic principle of the proposed current balancer with the proposed control method is discussed in detail, then confirmed by digital computer simulation with PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained in spite of unbalanced load currents.