Using VBR Model in Fixed Speed Wind Turbines and Suggesting a New Method for Improving LVRT Capability

Low Voltage Ride Through (LVRT) capability is essential for wind farms to avoid disconnection during low voltage and fault. In this study, both Voltage Behind Reactance (VBR) model and DQ model of Induction Generators (IGs) used in Fixed Speed Wind Turbines (FSWTs) are implemented and compared. Based on the appropriate model, a new method for enhancing Low Voltage Ride Through (LVRT) capability of FSWTs during balanced three-phase faults is proposed. This method is based on using a Synchronous Condenser (SC) with a Fuzzy Logic Controller (FLC). In order to have a good control of the system during the fault, the amount of injected reactive power produced by the SC is controlled through the FLC. Although using STATCOM is the most common method for LVRT capability enhancement in FSWTs, simulation results show that using the SC with the FLC in a three-phase fault leads to a better performance. Therefore, using the VBR model for the first time in FSWTs and suggesting the application of the SC with the FLC to improve LVRT capability are the novelties of this paper.