Rigorous analyses of a power distribution system with distribution transformer banks serving unbalanced loads and wind turbine generator systems

摘要

Three-phase power distribution transformer banks (DTrBs) are widely applied to serve single-phase lighting loads and three-phase power loads in a medium-voltage three-phase four-wire (3 phi 4W) power distribution systems simultaneously. Furthermore, the growing small-scale wind turbine generator (WTG) systems are directly connected to the secondary side of DTrBs. It has been found that the system imbalance of a power distribution system might be significantly enlarged when WTGs are operated in parallel. Because of the determination the system imbalances of these systems are extremely complicated. In this paper, we introduce an effective method to develop the mathematical models of asymmetrical DTrBs, rigorously. These models can be easily applied in an unbalanced 3 phi 4W power distribution system for more detailed analyses. In addition, such a kind of unbalanced system will be solved with an aid of the computer program, Matlab((R))/Simulink((R)), to analyze the effects of system imbalances when an asymmetrical DTrB serves the single- and three-phase loads and the WTG system in parallel operation simultaneously. The simulation results and conclusion are of value to power distribution engineers for better planning, operating, and promoting their distribution system. Copyright (c) 2016 John Wiley & Sons, Ltd.