Drift-Free Perturb and Observe MPPT Algorithm With Improved Performance for SEIG-Based Stand-Alone Wind Energy Generation System

This article proposes a drift-free perturb and observe (P&O) maximum power point tracking (MPPT) algorithm for a self-excited induction generator-based stand-alone wind energy generation system (WEGS). Conventional P&O algorithm gives more steady-state oscillation and fails to detect correct direction during wind speed increase condition. To avoid this, the proposed algorithm uses additional dc-link current information for the steady-state and transient conditions, which also decreases the power oscillation around maximum power point (MPP). During sudden wind speed change, the tracking speed of the algorithm increases considerably, and depending on sign of change in dc-link current, it perturbs in the right direction without drift. Corresponding theoretical analysis confirms that only in speed increase condition, the change in dc-link current sign is positive. To validate this algorithm, a laboratory prototype of the stand-alone WEGS is developed and implemented in DS1103 digital platform. The performance of the proposed technique is compared with both conventional speed sensor-based and speed sensorless algorithms. The proposed algorithm does not require any extra sensor to observe wind speed change and has a good tracking response and higher efficiency compared to conventional P&O.