풍력단지 변동출력 보상용 1 MJ급 SMES의 설계 및 운전특성 해석

Abstract

In wind power farm, the output fluctuation is strongly influenced by the change of weather condition. In case of the wind power energy output exceeds the critical margin of the total power generation sources (±10%), it will surely disturb the stability of the electric power system, as a result, the electric power system's quality will be debased. In consequence of this reason, the research has focused on improving the performance of wind power energy output by compensating the fluctuation power. It means the output energy will be emitted or absorbed by electrical energy storage (EES) whenever it is either insufficient or superfluous, respectively. Among various kinds of EES, Superconducting magnetic energy storage (SMES) is widely used nowadays since it can quickly charge and discharge high density energy. It also has a very profitable performance to compensate the output energy fluctuation because of surpassing charging and discharging characteristics. However, the current variation of superconducting magnet, which is generated during charging and discharging period, will provoke electromagnetic losses. These losses is composed by the two main losses: magnetization loss within superconducting wire and eddy current loss in the surrounding metallic components. They finally lead to the heat disturbance which is a decisive effect on SMES stability performance when SMES operates in cryogenics condition. In this paper, the optimal design of HTS magnet for 1MJ SMES system was carried out. The electric power output fluctuation in wind farm was effectively improved by applying SMES system application instead of conventional EESs. Moreover, the electromagnetic losses in SMES were calculated in term of numerical analysis method with current variation, and thermal characteristic of SMES was also analyzed by using 3D finite-element analysis (3D FEA).