Need

Metrology for electric vehicle charging systems

Need

The EC has adopted an ambitious roadmap for a competitive and sustainable transport system by 2050. With the expected integration of EVs, EVCSs are a key element in electromobility and, therefore, the Alternative Fuels Infrastructure Directive 2014/94/EU took measures to increase the number of standardised EVCSs. Though EVCSs may be considered simple meters, additional factors, such as grid distortion and dynamic impedance during charging, challenge their reliable operation. In addition, the detailed characterisation of the effects that EVCSs may have on the grid will be valuable to anticipate deteriorating Electromagnetic Compatibility (EMC) or Power Quality (PQ). Therefore, there is a need to characterise on-site local grid conditions in various charging scenarios.

The methods and standards applied in existing EVCS test benches do not reflect representative operating conditions. Also, characterisation of newer charging modes, such as DC charging at low power and ultra-fast charging at high power, smart charging, and bi-directional charging, is not well covered in standards.

Therefore, there is a need for establishing EVCS test benches for both DC and AC, implementing new measurement methods and standards reflecting representative operational conditions at low, medium, and high power levels, following IEC 61851-1. These test benches shall be capable of evaluating (i) metering accuracy and energy transfer efficiency with a target uncertainty of 0.1 %, and (ii) generated conducted emissions up to 150 kHz.

Knowing that the number of EVCSs is growing rapidly, there is a need to develop the metrological infrastructure for on-site verification of EVCS energy metering, in support of legal metrology. On-site verification requires reliable and efficient measurement procedures, based on commercially available equipment capable of handling representative operating conditions and charging scenarios. The uncertainty of the metering accuracy verification is targeted at 0.5 %.