C-link Ripple Voltage Compensation Algorithm for Integrated ESS and UPS System with PV Generation

태양광 발전을 갖는 통합 ESS 및 UPS 시스템의 직류 링크 맥동전압 보상 알고리즘

Using the ESS(Energy Storage System) as a UPS(Uninterruptible Power Supply) is being studied recently. When the system is operating at UPS mode in integrated ESS and UPS system, the grid supplying power is disconnected and power from PV generation and battery are supplying to load. Operating in UPS mode, when PV generation power is diminished by partial or total clouded situation, DC-link voltage fluctuates. The fluctuation of DC-link voltage influences the load and system as sensitive loads may malfunction. This paper suggests the DC-link ripple voltage compensation algorithm in bi-directional converter. The algorithm stabilize the DC-link and load voltage.