Power factor control in a wind energy conversion system via synchronous generator excitation

This paper proposes a novel control technique to improve the power factor over a wide range of wind speed in a wind energy conversion system (WECS) based on a current source inverter (CSI) and an electrically excited synchronous generator (EESG). The system consists of diode rectifier on the generator-side while a pulse wave modulated (PWM) C SI is on the grid-side. In the proposed control scheme, the generator excitation is controlled with the wind speed to improve the grid power factor. While the control freedoms of the CSI are used to regulate the power output of the WECS to meet maximum power point tracking (MPPT) of wind energy and deliver maximum power at any wind speed. Theoretical analysis was conducted to investigate the feasibility and limits of this approach, and computer simulations confirmed the validity of the theory.