Fault Analysis of PI and Fuzzy-Logic-Controlled DFIG-based Grid-Connected Wind Energy Conversion System

This research is based on the design of modified version of Type-III wind turbine system using DFIG (Double-Fed Induction Generator). The control technique associated with Type-III wind turbine system is Modified Type-I Fuzzy Logic Controller. Using this advanced form of controller, four different models are designed to control the active and reactive power during the transients and unwanted faults cause voltage sags. Mechanical Drive Train-modified Type-III DFIG-based wind turbine system during various fault conditions like voltage dip conditions, swell conditions with respect to variation in wind speed is explained in MATLAB model with control action of PI controller and Fuzzy Logic Controller (FLC) with grid integration. The research highlights implementations of four types of Fuzzy structures with different modes of operations that are modeled, and comparisons were made between all the structures with PI control structure for both steady state and dynamic state. The model is assembled to the lattice of grid, and the control of the model mechanisms using PI and FLC is studied to estimate the fast response of settling time after the removal of faults. The simulation is done to find the effective controller with respect to cost and economic point of view. The model is based on transient responses to calculate the settling time with application of various fault conditions. In this paper, DFIG, i.e., Double-Fed Induction Generator, is operated through variable speed and variable pitch angle control scheme which is now mostly implemented in power generation and distribution industries. In this paper, DFIG in wind turbine model is assembled to a constant frequency and constant voltage source and tied into a grid which is modeled using MATLAB and to the corresponding generator for operation and control action on active and reactive power are highlighted. The steady state operation and transient characteristics of the whole wind energy conversion system is explained with detail study with respect to the transients due to sudden change in wind speeds. © 2021, The Institution of Engineers (India).