Analysis of Effects of Distribution System Resources on Transmission System Voltages using Joint Transmission and Distribution Power Flow

With higher penetration of distributed photovoltaic (PV) resources and wider adoption of electric vehicles (EVs), it is reasonable to expect events at the distribution level to more actively influence the state of the network. However, traditional power flow formulations mostly consider either the transmission system or the distribution system. Recent work has been done in the development of a joint transmission and distribution (T&D) formulation to properly account for interactions between the two systems. This paper presents the analysis of effects of distribution system resources on transmission system voltages. The analysis relies on a recently developed power flow tool that combines distribution and transmission circuits. Results of multi-period power flow simulations are shown demonstrating how the location of PV and EV fast charging facilities in distribution circuits affects transmission bus voltages. Furthermore, the results are analyzed, and justifications are offered to explain the observed phenomena.