재생에너지 수용 시 폐지 발전기의 동기조상기 전환에 대한 영향성 분석 = An Analysis on the Conversion of Disclosing Synchronous Generators into Synchronous Condenser for the high Inverter-Based Sources Penetration

다국어 초록 (Multilingual Abstract)

As the penetration of inverter-based sources (IBR) based on variable-renewable energy (VRE), the stable operation of the power system is getting challenging since the operating synchronous generators (SGs) must be out-of-service for power balance between the generation and demand. In addition to the uncertainty and fluctuation of VRE-based IBR, the high penetration of the IBR reduces the system inertia because the portion of operating SGs must be decreased. However, the VRE-based IBR cannot provide the proper inertia which the SG can. As the result, the reduction of system inertia affect adversely with respect to the system frequency.
Especially, the rate of changes of frequency (ROCOF) is also increasing because of the declination of system inertia. This could cause consecutive frequency stability problems since the IBR must be tripped in the high ROCOF condition due to the self protection scheme. Therefore, the possibility of the cascaded black-out will be increased in the lack of system inertia. Traditionally, the synchronous condenser is a synchronous machine who can provide reactive power only in a power system to deal with voltage stability problems. Nonetheless its previous applications, synchronous condenser (SC) could be an alternative the adequate system inertia due to stability problem for providing missing system inertia. This paper analyzes the effect of SC with respect to frequency stability. For reflecting practical problem, the conversion of disclosing SG into SC as well as the installation of SC were all considered. Moreover, the reinforcement with flywheel was also examined in converting SG into SC cases. These analyses were carried out with IEEE 39 Bus Benchmark System by considering the introduction of VRE-based IBRs.