Phase-Precise Control of Electric Vehicles to Reduce Voltage Unbalance in Low-Voltage Grids

Abstract:
In this paper, the grid simulation software PowerFactory and a developed Python model are used to investigate phase-precise controls for electric vehicle charging based on characteristic curves, such as Q(V), to reduce voltage unbalance in low-voltage grids. The results show that with phase-precise Q(V), the voltage unbalance is affected positively or negatively depending on whether the phase shift approaches 120 deg or moves away from it. Therefore, the phase angle should not be neglected in phase-precise control. Furthermore, it is shown that the voltage unbalance mainly increases towards the end of a line.