Multi-Layer Architecture for Voltage and Frequency Control in Networked Microgrids

Networked microgrid can operate in different possible configurations including: islanded microgrid, a grid-connected microgrid without a tie-line converter, a grid-connected microgrid with a tie-line converter, and networked microgrids. These possible alternative configurations and intermittent renewable energy offer challenges in designing control and management algorithms for voltage, frequency, and power in all possible operating scenarios. In this paper, a novel multi-layer architecture for control algorithm is designed based on large-signal model that enables microgrid to operate in wide range of operating points. Goals of the designed controls are to regulate voltage magnitude and frequency, as well as output power of the distributed generations. Local controls also integrate with a microgrid level energy management system or microgrid central controller (MGCC) for power and energy balance for the microgrid in islanded, grid-connected, or networked microgrid mode. The MGCC coordinates the lower level controls in centralized manner. In this paper, with the communication network failure, local lower level droop control will be activated. Designed control algorithm works with high R/X ratio and simulation results indicate satisfactory performance.