Reactive power control strategy based on DC capacitor voltage control for active load balancer in three-phase four-wire distribution systems

Abstract

This paper proposes a reactive power control strategy for the active load balancer (ALB) in three-phase four-wire distribution systems. The proposed reactive power control strategy is based on constant DC capacitor voltage control only, which is always used in active power line conditioners. Therefore, the proposed approach does not require active and reactive calculation blocks of load currents for the reference source current calculation. The power factor of the source side currents can be adjusted under the balanced load condition using the proposed reactive power control strategy. The basic principle of the reactive power control strategy for the ALB is discussed in detail and verified via digital computer simulation using power electronic simulation (PSIM) software. A prototype experimental model is constructed and tested to demonstrate the validity and high practicability of the proposed control strategy. Simulation and experimental results indicate that balanced source currents with a predefined power factor are achieved when the proposed control strategy is applied to the three-phase four-wire distribution systems.