A New Implementation of PID-Type Fuzzy Controller for a Battery Grid-Supporting Inverter in an Autonomous Distributed Variable-Speed Wind Turbine

This paper presents a new implementation of a proportional-integral-derivative (PID)-type fuzzy controller (PIDfc) for a battery grid-supporting inverter to regulate the frequency and voltage of an autonomous distributed variable-speed wind turbine (VSWT). The VSWT which drives a permanent magnet synchronous generator (PMSG) is assumed for demonstration. The PIDfc is built from a set of control rules that adopts the droop control method and uses only locally measurable frequency and voltage signals. The output control signals are determined from the knowledge base and the fuzzy inference. To ensure safe battery operating limits, we also propose a protection scheme called intelligent battery protection (IBP). Several simulation experiments are performed by using MATLAB/SimPowerSystems. Next, to verify the scheme's effectiveness, the simulation results are compared with the results of a conventional controller through some performance indices. The results demonstrate the effectiveness of the PIDfc scheme to control a grid-supporting inverter of battery in the reduction of frequency and voltage fluctuations. (c) 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.