Comparative study of three types of controllers for DFIG in wind energy conversion system

Saïd Boubzizi,Mohamed Chaabane,Ahmed El hajjaji,Hafedh Abid

doi:10.1186/s41601-018-0096-y

Abstract

This paper presents an enhanced control strategy for Wind Energy Conversion System (WECS) using Doubly-Fed Induction Generator (DFIG). A robust Super-Twisting (STW) sliding mode control for variable speed wind turbine is developed to produce the optimal aerodynamic torque and improve the dynamic performance of the WECS. The electromagnetic torque of the DFIG is directly tracked using the proposed control to achieve maximum power extraction. The performance and the effectiveness of the STW control strategy are compared to conventional Sliding Mode (SM) and Proportional-Integral (PI) controllers. The proposed STW algorithm shows interesting features in terms of chattering reduction, finite convergence time and robustness against parameters variations and system disturbances.

Highlights

Over the last decade, wind energy has taken an increasingly important place in the field of electric energy generation
In order to prove the robustness performance of the proposed controller, its dynamic behaviour is compared with the conventional Sliding Mode (SM) and Proportional-Integral (PI) controllers under high wind speed variations
The wind speed variation would lead to aerodynamic power fluctuation and high mechanical effort, which results in less energy capture and poor performance in terms of active power generation

Summary

Introduction

Wind energy has taken an increasingly important place in the field of electric energy generation. It is necessary to develop more advanced control strategies for WECS To this end, several control methods have been designed and implemented for wind energy generation such as, vector control which is based on voltage and flux oriented vector using the d-q rotating frame to decouple the active and reactive power, [3, 4]. Several control methods have been designed and implemented for wind energy generation such as, vector control which is based on voltage and flux oriented vector using the d-q rotating frame to decouple the active and reactive power, [3, 4] This strategy is sensible to parameters variations of the system such as resistance and inductance variations. In order to prove the robustness performance of the proposed controller, its dynamic behaviour is compared with the conventional Sliding Mode (SM) and Proportional-Integral (PI) controllers under high wind speed variations.

Sliding mode control strategy

Torque estimation

Aerodynamic torque control

Conclusion