A novel method for control of distributed storage devices in distribution: Ripple voltage injection with frequency droop

Ripple voltage injection has been used to control distributed loads to implement demand response. In this paper, we propose a novel technique to improve ripple control by utilizing frequency droop to control the power flow of distributed storage devices. Droop enables an arbitrary number of distributed devices to communicate bi-directionally to achieve power sharing. The response time of such a system is defined by the control and does not change as the number of storage devices increases. By controlling distributed storage through ripple control, communication systems on the grid are freed to perform other functions. The proposed control technique is explained and design and simulation are presented for the application of controlling electric vehicle chargers on a distribution feeder for frequency support.