Analysis and systematic comparison of concepts for voltage control with inverted-based prosumer devices

Abstract

The German energy transition resulting in increased penetration of renewable energy generation and electrification raises the load on the electrical power grid. Especially the low voltage grid with rising shares of prosumer devices like photovoltaic systems and electric vehicles is affected by severe deviations of the bus voltage from nominal values potentially violating the limits of the voltage band. In this paper several voltage control concepts are analysed with a focus on supply quality, additional grid load, and losses. The concepts presented are implemented and analysed within simulative investigations. Main results are a positive effect of all concepts on bus voltages with no concept being superior in all key figures. The reactive power feed-in based on the current grid status using the Q(U) method presents the best trade-off for photovoltaic systems with regard to impact on critical voltage values and negative effect on the grid and prosumer devices. While a combination of Q(U) and P(U) is the most appropriate option for consumption devices, voltage control concepts for battery storage systems do not seem to have any significant impact. Adjusting the installation specifications of grid operators based on these results could mitigate critical grid situations in congested grids.