LVRT Capability Enhancement of DFIG Wind Turbines

Abstract

In an electrical power systems, low-voltage ride through (LVRT) is the ability of electric generators to stay connected in short periods of voltage dip under any abnormal situation. The usage of renewable sources are increasing with the advancement in technology and depletion of fossil fuels. So, because of that interest in wind energy sources are increased in which Doubly-fed Induction Generator (DFIG) is gaining prime importance. DFIG has mainly Low Voltage Ride-Through problem. The literature survey proposes various LVRT techniques like additional protection circuits installation to limit generated rotor over-current and undesirable dc-link over-voltage during grid disturbances. It also utilizes reactive power injecting-devices installation to surpass any deficiency of reactive power so as to improve the transient performance of DFIG. The standard test system of WSSC 9-bus is studied by replacing one of the synchronous machine by Type-III wind turbine and the results for the LVRT capability of wind turbine have been analyzed. Various techniques to improvise the LVRT capability have been suggested based on the results obtained.