A dynamic strategy to improve the ride‐through capability of a fixed speed induction generator. (5th February 2018) - Hong, Lucheng
Summary: Based on the analysis of the short current of the fixed speed induction generator (FSIG) under symmetrical system faults, a strategy using the dynamic voltage restorer (DVR) is proposed to improve the low‐voltage ride through (LVRT) capability of FSIGs. During the system fault, LVRT‐DVR is connected in series between the grid and the generator by switching‐off the by‐pass bidirectional thyristors and provides a compensating voltage to isolate FSIG from the system fault. To increase the switch‐in speed of LVRT‐DVR, an antivoltage technique is used to shut the thyristors off immediately. After the fault is cleared, the phase‐shifting control is applied to avoid phase jumps of the FSIG terminal voltage. The PSCAD/EMTDC simulation and field tests have been carried out to prove the effectiveness of the proposed LVRT strategy, and related conclusions and comments are summarized.