A Multilayer Preventive Control to Regulate Voltage and Frequency in Autonomous Microgrids

Abstract

This paper proposes a method to prevent the frequency and voltage excursion in autonomous microgrids beyond their predefined desired ranges, following any change in load and/or renewable energy output. The proposed technique utilizes the short-term prediction data of load and renewable generations to determine any prospective occurrence of events that violate the microgrid’s predefined range of frequency or voltage. It then determines the optimal generation for dispatchable sources and the MG’s most appropriate topology as first options to prevent the violation. If it is not enough, the proposed technique goes on to engage in supporting actions, such as exchanging power with neighboring microgrid, utilizing energy storages, demand response and renewable energy curtailment. It considers the technical, reliability and environmental aspects of the MG along with the operational cost, as well as the cost of supporting actions. The optimized control variables are sent to the local controller before the occurrence of the event to maintain the frequency and voltage within the desired limits.