DFIG wind turbine fault ride through capability improvement with control strategy

摘要

To enhance the performance of doubly fed induction generator (DFIG) wind turbine during low voltage events, a battery energy storage system (BESS) together with advanced control schemes are proposed. The novel control strategy utilizes the existing devices within the DFIG wind turbine system to achieve low voltage ride through (LVRT) by controlling rotor and grid side converters and BESS. The advanced control scheme can save the major excessive power into turbine inertia by accelerating the turbine rotating speed. Therefore, relatively small quantity of power will flow into dc-link, which can reduce the capacity of BESS. Moreover, the sequence of control scheme and BESS activation time was discussed in this paper which can help us to determine the battery charging period. Through this cooperated control scheme, the sensitive power electronics devices can be protected against current and voltage fluctuations. The proposed control scheme is validated through dynamic simulations.