Novel Control Algorithm for Active Load Balancer in Three-Phase Four-Wire Distribution Systems

Abstract

Three-phase four-wire distribution systems are widely used in many countries. These distribution systems are used for both three-phase three-wire loads and single-phase two-wire consumer appliances, e.g., in South Korea and Myanmar. Because of the time-dependent load characteristics, unbalanced load conditions frequently occur, resulting in the unbalanced voltages for the three-phase and single-phase loads. In addition, these unbalanced load conditions cause more loss in the distribution transformer. This paper proposes a novel reference current generation method for active load balancer (ALB) in the three-phase four-wire distribution systems. The main advantages of the proposed method is that it uses only a constant DC capacitor voltage control for reference current generation without calculating the active and reactive currents in the three-phase four-wire distribution systems. The basic principle of the novel reference generation method in ALB is discussed and then confirmed on the basis of results of digital computer simulation using PSIM software.

Harmonics Compensation in Three-Phase Four-Wire Distribution Feeders With a Four-Leg Structured Active Power-Line Conditioner

“…Connecting single-phase loads to TPFWDFs causes unbalanced feeder currents. The present authors proposed an active load balancer in TPFWDFs to achieve the balanced source currents with a unity PF, where unbalancedlinear loads were connected (1) . Modern consumer electronics are with single-phase diode rectifiers, which generate a large amount of harmonic currents in distribution feeders (2) .…”