Voltage Regulation in Islanded Microgrids Using Distributed Constraint Satisfaction

Droop control is a key control method for operating islanded microgrids (IMGs). The settings of the droop parameters for distributed generation (DG) units can considerably affect the ability of an IMG to satisfy the required voltage tolerance boundary prescribed in steady-state voltage regulation standards. This paper analyzes the complexity of voltage regulations in droop-controlled IMGs. A new algorithm is proposed to satisfy the voltage regulation requirements of IMGs. The proposed algorithm obviates the need for a centralized secondary controller, where each DG unit updates its own voltage droop parameters, autonomously, via interaction with other DG units, using a low-bandwidth, peer-to-peer communication network. To that end, a distributed constraint satisfaction approach is adopted to formulate the problem of voltage regulation in a multi-agent environment. An asynchronous weak commitment technique is proposed to solve the formulated problem. Several case studies are simulated to evaluate the performance of the proposed algorithm. The results show that the proposed algorithm can effectively mitigate the challenges of voltage regulation in IMG systems.