A Control Method for Inverter-Based Islanded Microgrids Based on V-I Droop Characteristics

Microgrids´ performance and stability mostly depend on power-flow control strategy. In order to allow for coordinated control while maintaining reliable operation, decentralized control methods based on P and Q droop characteristics have been utilized. Inherently, the power droop control methods have slow dynamics. In this paper, a novel control method based on V-I characteristics is introduced to exploit the flexibility and fast dynamics of the inverter-based distributed energy resources. In the proposed method, the direct and quadrature axis voltage components are drooped with the corresponding currents according to a piecewise linear droop function. Eigenvalue analysis of a sample microgrid shows that the proposed method features faster dynamics and improved damping compared to the conventional droop scheme. Simulation results are presented to verify the efficacy of the proposed method.