Coordinating storage devices, distributed energy sources, responsive loads and electric vehicles for microgrid autonomous operation

A microgrid can operate in two different operating modes, i.e. utility-grid connected mode or autonomous mode. In this paper, the operation of a microgrid with fully inverter-based renewable sources in transition from utility-grid connected mode to the autonomous mode is investigated. Energy storage device as a kind of buffering system might compromise microgrid autonomous operation due to the limited capacity; hence, available electric vehicles and responsive loads in the microgrid are used in primary frequency control upon separation from the utility grid. Secondary frequency control is performed by slow-response sources. In order to establish a readiness for upcoming disturbances, the state of charge of the energy storage device is held in a secure range by proper coordination and management of the electrical vehicles, responsive loads, energy storage devices and controllable microsources. The proposed control strategy is standalone and does not need any communication link in controlling the sources and loads. Copyright (c) 2014 John Wiley & Sons, Ltd.