Reactive Power Management of a DFIG Wind System in Microgrids Based on Voltage Sensitivity Analysis

This paper addresses the problem of voltage regulation in microgrids that include doubly fed induction generator (DFIG)-based wind generation. Due to significant line resistances in microgrids, active power variations produced by wind turbines can lead to significant fluctuations in voltage magnitudes. This paper proposes a voltage sensitivity analysis-based scheme to achieve voltage regulation at a target bus in such microgrids. The target voltage can be of an important central bus, or a bus with sensitive voltage loads. The method is local and can be implemented in the absence of a widespread communication system or remote measurements. The performance of the method is illustrated on the IEEE-13 bus distribution network. Dynamic models are considered for the DFIG, converters, and internal controllers along with their operational limits. Stochastic fluctuations in wind speed are modeled with NREL Turbsim while accounting for tower shadow and wind shear. Dynamic simulations (in PSCAD/EMTDC) are presented to assess the voltage regulation characteristics under different load conditions and network contingencies.