단순병렬 자가발전 설비 보호방식 검토 사례

A case Study for Protection Relay System of small Cogeneration intertie

The Co-Gen System which maximize energy efficiency was installed at the industrial plants at the initial stage. However Small Scale Co-Gen System was expanded even to the general end-users such as housing and building owing to ESCO business recently. For this SSC, inter-connected operation to the utility is desirable due to voltage and frequency fluctuation following to unbalance between power output and load. Then voltage unbalance with utility system, frequency, increase of short circuit capacity, reclosing, and ALTS etc. should be fully considered for the inter-connected operation. Voltage variation, protection coordination, Co-Generators single running, and short circuit capacity should also be solved. To research the method and solve the problems through the field test and application, we study individual customers Co-Gen System as a case study.