Design, analysis, and adaptive maximum power point tracking control of small-scale wind turbine system

Due to the stochastic and unpredictable nature of wind speed, extraction of maximum power from the wind turbine system becomes an attractive control objective. Therefore, to capture more wind power, various conventional maximum power point tracking (MPPT) schemes are developed for standalone small-scale variable speed wind power generation system (VSWPGS). This manuscript proposes novel adaptive step size (ASS) and drift-free ASS (DF-ASS) MPPT methods for a permanent magnet synchronous generator (PMSG)-based VSWPGS. The control schemes achieve maximum power point (MPP) without using mechanical sensors like speed encoder and anemometer. The proposed MPPT controllers are implemented on a laboratory-scale DC motor-PMSG-based wind power generation system (WPGS) using OPAL-RT real-time digital platform. The ASS and DF-ASS methods capture more power, reduce the steady-state power oscillation around MPP, and improve the tracking speed. Also, the proposed DF-ASS control scheme avoids drift phenomenon during wind speed increase condition. The comparative experimental results of proposed ASS and DF-ASS methods with respect to the fixed step size MPPT schemes show better dynamic and steady-state performance, making it pertinent for small-scale WPGS.