Smart Loads for Improving the Fault-Ride-Through Capability of Fixed-Speed Wind Generators in Microgrids

摘要

In this paper, the smart load formed by the back-to-back electric springs (ES-B2B) is evaluated for improving the fault-ride through (FRT) capability of the wind turbine generation system with fixed speed induction generator (FSIG) for the first time. The characteristic of the ES-B2B in providing fast reactive power compensation is found to be highly useful in recovering the rotor speed of FSIGs when a fault event occurs. This is a new function in addition to the original function of stabilizing mains voltage against renewable generations. A simple and yet effective controller is then developed for the ES-B2B in order to ensure fast response. The ES-B2B-based smart load and the proposed control have been tested in MATLAB/Simulink and real-time digital simulator to evaluate: 1) the reactive power compensation capability of ES-B2B; 2) the effectiveness of the proposed control of ES-B2B for FRT support; and 3) the comparison of distributed ES-B2Bs with centralized STATCOM in providing distributed FRT support in different grid topologies.