Combined parameters selection of a proportional integral plus resonant controller for harmonics compensation in a wind energy conversion system

This paper introduces the use of the Naslin polynomial technique in order to tune a proportional integral resonant (PIR) controller for the rotor-side converter of a grid-connected wind energy conversion system (WECS), which is based on a back-to-back converter and a doubly fed induction generator (DFIG). The objective of the proportional integral part of the PIR controller is to control the active and reactive power of the rotor-side converter, while the resonant part of the PIR controller deals with the stator current harmonics of the generator due to grid voltage distortions. Most papers that use PIR controllers for WECS often carry out the separated tuning of the PI part and then the tuning of the resonant part without any guide. In this paper, the tuning of the PIR controller as a single controller is proposed taking into account the mathematical base of the Naslin polynomial technique. The case of study is a WECS based on a 50 HP DFIG, and the considered grid voltage harmonics are the fifth and seventh. Simulations were implemented to evaluate the compensation of the current harmonics with the selected PIR controller values.