Design of future distribution grids

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

This work presents the concept of voltage control in power distribution systems with distributed generation and electric vehicles penetration. The impact of DG and EV in the voltage supply is investigated. DG provides more power into the system, which can cause the inversion of the load flow and an increase in the voltage supply when the demand is low. EVs on the other hand are additional load in distribution systems, increasing power demand and voltage drop. Both might be a cause of voltage problems in the power supply, when no voltage control is applied. Devices such as the tap-changer transformer or the voltage regulator which were not essential in the past are now important solutions to solve voltage variation issues. In this work, several different solutions for voltage control are analyzed, both technically and economically. Overall, the results show that different strategies have different outcomes, and some solutions provide better voltage control than others. In order to have a proper solution for a system, when choosing a control strategy, it is necessary to always take into account the cable ampacity, the technical limits of each device and the costs associated with it.