Active load balancer on three-phase four-wire distribution systems with constant DC capacitor voltage control for multiple loads

This paper deals with compensation performance of an active load balancer (ALB) with the constant DC capacitor voltage control based strategy under multiple feeders. Instantaneous power flow into the ALB show that the balanced source currents with a unity power factor are obtained on the feeder that is connected to the ALB. Thus the ALB is not over loaded although the constant DC capacitor voltage control based strategy is used under multiple loads. Digital computer simulation is implemented to confirm the validity and high practicability of the ALB with the constant DC capacitor voltage control based on strategy under multiple feeders. A prototype experimental model is also constructed and tested. Simulation and experimental results demonstrate that the ALB with the constant DC capacitor voltage control based strategy compensates the unbalanced active and reactive components on the ALB connected feeder while the unbalanced current conditions are remained on other feeders. Thus, the ALB is not overloaded even it is used in the multiple distribution feeders.