Improving the Frequency Response of DERs Through Voltage Feedback

This paper studies the ability of Distributed Energy Resources (DERs) to improve, through a proper voltage feedback signal, their primary frequency response by mitigating the part of the injected active power that does not contribute to the frequency regulation. The feedback signal modifies the reference of the DER voltage regulation loop and requires measuring the voltage magnitude at the buses to which the DER is connected. A simplified DER model, as well as a dynamic model of an ESS (Energy Storage System) are employed to test the examined technique through time domain simulations based on the WSCC 9-bus system.