Modeling and MPPT Control in DFIG-Based Variable-Speed Wind Energy Conversion Systems by Using RTDS

Abstract

The generating systems use Doubly-Fed Induction Generators (DFIGs) to achieve high conversion efficiency and to reduce the installation cost. This paper presents a modeling and Maximum Power Point Tracking (MPPT) control method of DFIG-based variable-speed wind energy conversion system. The generator considered is a wound rotor induction machine whose stator is connected directly to the grid and the rotor is fed through back-to-back Pulse-Width Modulation (PWM) converters. Stator flux-oriented vector control is applied to control the active and reactive current loops independently. The MPPT control method in a Wind Energy Conversion System (WECS) is proposed. The proposed control solution aims at driving the position of the operating point near to optimality. This is a very important aspect to maintain DFIGs efficiently in a variable wind speed. The wind generator is modeled in RSCAD program which is interfaced with the Real Time Digital Simulator (RTDS).