Experimental investigation of efficient and simple wind-turbine based on DFIG-direct power control using LCL-filter for stand-alone mode

Abstract

This paper suggests an experimental implementation study of the Wind Energy Conversion System (WECS) based on efficient Direct Power Control (DPC). Stand-alone mode for variable wind speed application using Doubly-Fed Induction Generator (DFIG) is studied and developed in this work. Due to the wind power performance limitation of traditional PI controllers, such as overshoot, response time, and static error; IP (integral–Proportional) controllers is replaced instead of the PI to control rotor current d–q components (Ird and Irq) in a Park frame through AC–DC–AC converter. A comparative experimental study was implemented to improve the power quality using L, LC & LCL passive filters between the DFIG’s rotor circuit and the inverter. Experimental results prove that the proposed DPC under stand-alone mode with LCL-Type filter could operate in several conditions despite the sudden wind speed variations. It improves the unity power factor grid operation (≈0.98), dynamic responses, and the decoupled power control with high wind power performances: good reference tracking, short response time, neglected overshoot, and low power error. The power quality injected into the RL-load satisfied the limit specified by IEEE harmonic standard 519 (less than 5%).