Dynamic reactive power in compliance with low voltage ride-through enhancement for DFIG-based wind turbine

Abstract

Wind power plant is regarded as a large-scale system where the interconnections between each subsystem cannot be neglected, otherwise the control strategy cannot guarantee the robustness and system satisfactory efficiency over a wide range of operation. Moreover, voltage stability is the most important ancillary service to preserve doubly fed induction generator (DFIG) connected to the grid during fault, known as Low Voltage Ride-Through (LVRT). In this paper, multiple local controller strategy is introduced to improve LVRT capability and to guarantee the system-wise stability. However, voltage at individual point of common coupling (PCC) is controlled to minimize the risk of instability because of high flow reactive power. Unlike classical decentralized methods, all energy and material flows are bounded by real constraints in this paper. A model of wind farm equipped with DFIG is also introduced to illustrate the effectiveness of proposed algorithm.