Flexibility Envelopes for Distribution Networks

The rapid growth in renewable generation in distribution system is introducing significant uncertainties and technical challenges in the energy management of the grid. This paper develops the concept of flexibility envelopes for distribution systems. Flexibility envelopes provide bounds on uncertain power flows and bus voltages caused by renewable generation fluctuation with certain confidence levels. First, shift factors for the distribution network are derived based on a set of linearized distribution power flow equations. Flexibility envelopes are obtained based on these shift factors. We demonstrate the effectiveness of our approach on the IEEE-33 bus system.