Investigation of Network Code Compliance for Electric Vehicle Onboard Chargers in Denmark

The increasing penetration of distributed energy resources in power grids poses significant challenges for grid operators. For a safe operation, inverter-based generators must comply with network code on requirements for generators (low voltage ride-through as well as start-up and reconnection). However, these requirements evolved at a different pace from the actual operating performance of distributed generation and storage technologies, such as solar photovoltaic inverters and electric vehicles (EVs). Thus, compliance with these requirements is not guaranteed. In this paper, the start-up and reconnection requirements of EVs are evaluated over a range of voltage and frequency disturbance scenarios. Tests have been carried out at SYSLAB, part of Technical University of Denmark (DTU) over a range of operating conditions using EVs from different manufacturers. Tested operating conditions include reconnection to the grid at different voltage and frequency set-points ranging from 360 to 440 V and 48.5 to 51.5 Hz. The results indicate that the tested components do not fully comply with the ride through and cease-of-operation requirements, which may pose serious risks to safe power grid operation, especially as the uptake of these technologies increase.