Dynamic and Transient Analysis of LVRT Augmented Grid Tied DFIG based Wind Turbine

Abstract

This thesis aims to present Low Voltage Ride Through (LVRT) augmentation of the gridtied Doubly Fed Induction Generator (DFIG) based wind turbine. Voltage stability is a critical grid code criterion that must be strictly adhered. A substantial voltage drop happens during a fault or network disruption situation, which must be restored as quickly as possible. According to modern grid code standards, 90 percent of the voltage must be restored to pre-fault levels in 1500 milliseconds. As a result, both dynamic and transient assessments are performed to evaluate the intended power system's LVRT capabilities. In this study, fault analysis including the most severe 3LG fault under transient conditions has been examined in order to evaluate the tuned PI controller scheme and resilience of the developed power system model. PSCAD/EMTDC® v4.5 tool has been used extensively to develop the DFIG wind turbine aerodynamic model, DFIG control scheme and power system model analysis. Simulation results show that tuned Proportional Plus Integral (PI) controllers effectively augment the LVRT functionality by injecting sufficient reactive power into the grid during fault or network disturbance scenarios.