Investigations Into Real Time Control and Interconnection of Microgrid to Electric Power System

Abstract

The research aims to investigate and solve some of the major real time control problems associated with interconnection of microgrid under various EPS conditions, such as normal, balanced and unbalanced fault. The thesis first proposes a modular and reconfigurable multifunctional power converter building block (PCBB) to facilitate the connection of microgrid to Area EPS. With proposed combined active and reactive power control scheme, the PCBB enables microgrid to operate under both EPS connected operating scenario and islanding scenario. This thesis also proposes digital controlled PCBB to enable the distributed generators inside microgrid to ride through EPS low voltage fault. Next, the parallel redundant PCBB system is investigated for higher power rating and increased system reliability. The control strategies for parallel redundant PCBB systems are proposed to minimize the circulating current, improve the system efficiency and expand system life span. A methodology to determine the architecture of the parallel inverter system in terms of reliability and cost optimization is proposed.