Fuzzy-PI-based sensorless frequency and voltage controller for doubly fed induction generator connected to a DC microgrid

摘要

This study presents fuzzy-proportional-integral (PI)-based sensorless frequency and voltage control strategy for doubly fed induction generator connected to a dc microgrid system. A significant reduction of the costs can be achieved by this topology because only a single dc/ac converter and a diode rectifier are required instead of the traditional back-to-back converter topology. To improve the performance of the rotor current controller, a fuzzy PI-based control algorithm is used. Furthermore, a simple sensorless control technique based on the detection of the stator frequency is employed to detect the rotor position. The sensorless control technique can operate without the knowledge of the machine parameters. The main aim of this study is to keep the stator frequency as well as the dc bus voltage at the desired value under different load and wind speed conditions without using position sensor. Simulation and experimental studies were performed to verify the dynamic and steady-state performances of the proposed control strategy The results show that the proposed strategy not only has an excellent steady state and dynamic performance, but also it is robust against the variation of system parameters such as wind speed and load.