A sensorless scalar-control strategy for maximum power tracking of a grid-connected wind-driven Brushless Doubly-Fed Reluctance Generator

This paper presents a sensorless scalar volt per hertz (v/f) control technique for maximum power tracking of a grid-connected wind-driven Brushless Doubly-Fed Reluctance Generator (BDFRG). The proposed generator has two stator windings namely; power winding, directly connected to the grid, and control winding, connected to the grid through a bi-directional converter. The capability of the proposed sensorless scalar control for maximum wind-power extraction is based mainly upon the validity of the BDFRG speed-estimation approach. A simple and a cost-effective speed-estimation approach is presented. In order to enhance the performance of the proposed control system, a soft starting method is suggested to avoid the over-current of the bi-directional converter. The presented simulation results ensure the capability and the effectiveness of the presented control strategy for maximum wind-power extraction under wind-speed variations using a sensorless scalar control technique.