A new dynamic strategy for improved ride-through capability of wind turbine generator

As the penetration of large-scale grid-connected wind farms increasing year by year, low voltage ride-through (LVRT) capability are required by many countries for power quality and fail-safe operation at grid fault. A new dynamic strategy using dynamic voltage restorer (DVR) is proposed in this paper to improve LVRT capability of wind turbine generators (WTGs). During the voltage dip, LVRT-DVR will be connected in series on the connection between grid and the generator by opening the static switch cabinet. And the power balance between grid and generator is achieved by using the dynamic braking resistor of LVRT-DVR. In order to increase the response speed of LVRT-DVR, anti-voltage technology is used to make the SCRs in static switch cabinet shutting off immediately. PSCAD/EMTDC simulations are carried out to prove the effectiveness of the proposed technique and some related conclusions and comments are summarized.