Maximum power point tracking of PMSG based grid connected WECS using quadrature axis current

This article proposes the ways to track the maximum power points (MPP) using the torque component (quadrature axis current component) of field oriented controlled (FOC) permanent magnet synchronous generator (PMSG) based grid connected wind energy conversion system (WECS). These methods reduce the time delay to track the exact optimum points using the power versus speed characteristics of WECS and are useful to track the optimum points during rapidly varying wind conditions. This research analyses the position of operating points using power signal feedback (PSF) and optimum torque (OT) MPPT methods and emphasizes that the position of MPP using these methods will not be the exact optimum point due to non unique nature of optimum constant. This article also finds relation between the quadrature axis current component of PMSG, DC-link power and speed and proposes two ways of tracking optimum point that results in fast tracking due to faster settling of quadrature axis current. The back-to-back converter is used in this research and are controlled by sinusoidal pulse width modulation (SPWM). The efficiency of the proposed methods have been verified by simulation and experimentation.