Intentional Islanding Operation to Improve the Service Reliability of Thailand Electric Power System

Following the steps of the gas industry, the traditional paradigm of the vertically integrated electrical utility structure has changed. The crisis in California has drawn great attention and sparked intense discussion within the utility industry. One general conclusion is to rejuvenate the idea of integrated resource planning and promote the distributed generation (DG) via traditional or renewable generation facilities for the deregulated utility systems [1,2]. Traditionally, interconnection standards avoid islanding operation of distributed generation, DG, due to the concerns of equipment failure and safety issues. However, in some cases, allowing of islanding of DG connected to radial subtransmission system could improve the system reliability and decrease outage cost during power outage or schedule maintenance [3-6]. In order to improve the service reliability of Thailand electric power system (EPS), this paper performs both quasi-steady state and dynamic studies of a sample subtransmission system to explore possible arrangements and operation strategies to allow DGs to be continue operated under islanding conditions.