Frequency control of islanded wind‐powered microgrid based on coordinated robust dynamic droop power sharing

Abstract

This study proposes a new frequency control of islanded and storage independent wind-powered microgrid based on coordinated robust dynamic droop power sharing. The islanded microgrid includes wind turbine as undispatchable distributed generation (DG) and fuel cell as dispatchable DG. In the first layer of control, the reverse and direct droop controls are considered for wind turbine and fuel cell, respectively. Accordingly, the outputs of reverse droop control are active and reactive powers, which are used for wind turbine. Simultaneously, the outputs of direct droop control are frequency and voltage, which are used for the fuel cell. Since the generated power of wind turbine is not constant, so the coordinated dynamic droop coefficients for both DGs are modified as a function of available wind power. Then in the second layer, robust sliding mode control is designed for setpoints tracking of both DGs to control the frequency and voltage of islanded microgrid. The effectiveness evaluation of the proposed control scheme is performed by simulation studies on the islanded microgrid in different conditions such as single-phase fault, load step change and variety of wind speeds in MATLAB/Simulink environment. Finally, results are validated experimentally through the implementation of real-time hardware-in-the-loop system.