Load Sharing by Decentralized Control in an Islanded Inverter-based Microgrid using Frequency Tracking

Abstract

Microgrids have been defined as an efficient and practical concept to cover flaws in traditional power system related to system expansion and renewable energy utilization. By increasing demand energy, the need to generate more electric power is raised. However, the distance between generation centers and consumption centers causes more energy loss in power system and power system expansion is considered costly and to some extent infeasible. In addition, nowadays using renewable energies such as wind energy is inevitable, as a result using power electronic mediums is necessary. Microgrids are mostly preferable because of the ability to perform in islanded mode. In order to have stable-islanded Microgrid, electric loads inside the network should be shared on Voltage Source Converters respect to their nominal capacity. Droop control has been known as a method to share loads in decentralized way, although it has shortcomings. In this paper by introducing novel method named Frequency Tracking and applying that on droop control system, electric loads inside an islanded Microgrid are shared on generation units properly with fast and acceptable dynamics and droop control system is modified. Simulation results in PSCAD are confirmation of proposed system to have stable islanded Microgrid.