Frequency Profile Improvement of a Microgrid through Aggregated Demand Response

The frequency deviation of a system from its nominal value is a significant indicator of the system’s stability. This issue is further highlighted when the system is incorporated with intermittent renewable energy resources. In this work, frequency regulation of a microgrid is achieved by aggregated demand response. The proposed aggregator is implemented in a central controller that controls frequency deviation by manipulating responsive loads. In case of higher frequency deviation, an adaptive control action which is proportional to the magnitude of frequency deviation manipulates a large number of responsive loads to quickly restore the frequency to its nominal range. The amount of manipulated responsive load is reduced by another section of the central controller which deals with minor frequency deviations as well. The proposed control scheme is implemented on a test system and obtained results verify the desired functionality of aggregated demand response controller.