전기저장장치용 SPD의 최적운용 평가 알고리즘에 관한 연구

Abstract

Recently, ESS(energy storage system) for output stabilization of renewable energy source, peak demand management, frequency control, etc. is actively installed and operated. However, as the fire accidents are continuously occurred in ESS, the Korean government has presented the causes of fire accidents and countermeasures for safety enhancement through the public-private joint accident investigation committee, which recommends the installation of electrical protection devices such as SPD(surge protect device) and IMD(insulation monitoring device). However, it is reported that the capacity of SPD (USUBc/SUB, USUBp/SUB) installed and operated in each ESS site is different and improper due to the absence of installation regulations. When the inappropriate capacity of SPD is adapted at DC side in ESS, there are possibilities that the battery may be negatively affected as SPD cannot properly protect the battery from the lightning and switching surges. Therefore, this paper proposes an algorithm to calculate the appropriate capacity of SPD for the stable operation of ESS and performs the modeling of surge test device, which is composed of surge generator, SPD, battery, etc., using PSCAD/EMTDC, in order to evaluate operation characteristics of SPD for the lightning and switching surges. And also this paper implements surge test device which generates 3rd class combination wave for lightning surge and switching surges. From the simulation and test results based on the presented modeling and test device, it is confirmed that the SPD can safely protect the battery from the lightning and switching surges when the proper SPD calculated by the proposed algorithm is installed.