Stability of a microgrid with wind power generation

Abstract

This thesis presents dynamic modeling of the microgrid with wind-turbine driven squirrel cage induction generator and doubly-fed induction generator, synchronous generator, and some constant-power load. The natural fluctuation of wind speed is modeled using Weibull distribution. The system dynamic performances under both small and large disturbances, including islanding mode of operation have been examined, and compared among the three different control schemes: fixed-speed, variable-speed with VAr control and variable-speed with voltage control. Special attention has been paid to the resulting fluctuations of generated power from wind station and its impact, especially under short-circuit on the tie-line stabilizing flow and frequency fluctuation of the microgrid. Moreover it also investigates the impact of local capacitor switching, for conventional reactive power compensator, on the stability of the microgrid system. In addition to the time domain simulation, the small signal analysis of the linearized system has been conducted in order to examine the small signal stability of the microgrid. The test results here could be applied to addressing appropriate control performance requirements to ensure reliable and stable operation of the microgrid with wind power generation in the future.