Secondary control strategy of islanded micro-grid based on multi-agent consistency
The technology of virtual synchronous generator has attracted much attention in the field of distributed generation and micro-grid, as it could simulate the internal mechanism and external characteristics of synchronous generator. Affected by the new energy power generation, line impedance, local load and other factors, inverters using the droop control or VSG control (differential regulation) cannot ensure the stable operation of the micro-grid, so the secondary control of frequency and voltage of islanding micro-grid is essential. Aiming at the limitations of centralized and decentralized control, a control method of distributed hierarchical control method based on dynamic consistency algorithm has proposed. The distributed micro sources are equivalent to the agents, and each agent only use local information and adjacent agent's information interaction through the consistency algorithm, then control the P-f curve adaptively by using the PI controller's function, thus the constant frequency and power allocation have been realized. The physical simulation model of micro-grid has established on the MATLAB/Simulink simulation platform, and its performance in different operating conditions is simulated and analyzed, with the correctness and effectiveness of the proposed secondary control method are verified.