Voltage balancing and synchronization of microgrids with highly unbalanced loads

Abstract

Microgrids can operate in parallel with the grid or as a power-island. They are thus, expected to perform seamless transition from islanded to parallel operation and vice versa. This paper reviews the existing DG interconnection standards for microgrid resynchronization, investigates possible simple solutions for voltage balancing, and shows that the existing synchrocheck relay with a circuit breaker is sufficient to reconnect an islanded, highly unbalanced microgrid back to the utility grid.