Fault Studies and Distance Protection of Transmission Lines Connected to DFIG-Based Wind Farms
AbstractDoubly fed induction generator (DFIG) based wind farms are being increasingly integrated into power grids with transmission lines, and distance protection is usually used as either the main or the backup protection for the transmission line. This paper analyzes the composition of a DFIG short circuit current and indicates the existence of a rotor speed frequency component. By analyzing several real fault cases of the DFIG-based wind farms connected to transmission lines, the weak power supply system and current frequency deviation of the wind farm side are illustrated. When a fault occurs on the transmission line, the short circuit current on the wind farm side is small and its frequency may no longer be nominal due to the existence of rotor speed frequency component, whereas the voltage frequency remains nominal frequency because of the grid support. As a result, the conventional distance protection cannot accurately measure the impedance, which can result in unnecessary circuit breaker tripping. Therefore, a time-domain distance protection method combined with the least-squares algorithm is proposed to address the problem. The efficacy of the proposed method is validated with real fault cases and simulation. View Full-Text
Share & Cite This Article
Li, B.; Liu, J.; Wang, X.; Zhao, L. Fault Studies and Distance Protection of Transmission Lines Connected to DFIG-Based Wind Farms. Appl. Sci. 2018, 8, 562.
Li B, Liu J, Wang X, Zhao L. Fault Studies and Distance Protection of Transmission Lines Connected to DFIG-Based Wind Farms. Applied Sciences. 2018; 8(4):562.Chicago/Turabian Style
Li, Bin; Liu, Junyu; Wang, Xin; Zhao, Lili. 2018. "Fault Studies and Distance Protection of Transmission Lines Connected to DFIG-Based Wind Farms." Appl. Sci. 8, no. 4: 562.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.