Impact of PV Inverter Generation on Voltage Profile and Power Loss in Medium Voltage Distribution Systems

With an increasing number of photovoltaic (PV) generators at the distribution system, the impact on the distribution system is no longer negligible. This paper presents a comparison among PV generators of different capacities, different injection locations, and different reactive power control modes, to determine their impact on the system voltage profile and power loss. Voltage sensitivity analysis is conducted to assess the impact of PV injection on system voltage profile quantitatively. Further, it is shown that sensitivity matrices are irrelevant from system operation state, but closely related to the system topology and impedances. The accuracy of these sensitivity indices is proven by calculation results from MATLAB and simulation results from PSS/E. Guidelines are formed for utility to manage PV injection locations and regulate PV generator reactive power control to avoid voltage profile problems and reduce power losses. In comparing different PV injection locations, there is a tradeoff between voltage regulation and power loss minimization.