Fuzzy-Based EV Charging Station and DVR-Fed Voltage Compensation for a DFIG-Fed Wind Energy System during Grid Faults

Abstract

In recent years, it can be seen that more and more wind energy systems are integrated to focus on developing a more reliable energy system. A doubly-fed induction generator is the most employed machine in wind energy systems having the advantages of variable speed operation, improved power quality, and high energy capture. In a wind energy conversion system (WECS), the generator’s capability to remain connected during short electric faults resulting in voltage sag is known as fault ride through (FRT). Over the last few years, electric vehicles have been providing a remarkable solution for many sustainability issues such as global warming, depletion of fossil fuel reserves, and emission of greenhouse gas that needs attention to detail. A voltage compensation using Dynamic Voltage Restorer and Electric Vehicle charging station both employing a fuzzy controller is proposed in this paper for sustaining FRT capability. The variation in the stator voltage is tracked and utilized to inject the necessary shortfall of voltage in the system via DVR or EV charging station for the intensity of the created voltage sag. Vehicle-to-grid unit of the electric vehicle charging station comes into action when voltage sag intensity is 0.9 p.u. to 0.51 p.u. Value of the nominal voltage and the DVR takes over when voltage sag falls between 0.5 p.u. and 0.2 p.u. Consequently, this voltage compensation regulates the other relative parameters like DC link voltage and active power and retains them within the permissible limits during the fault.