Measurement of ABB´s Prototype Fast Charging Station for Electric Vehicles

In this study, measurements on a prototype CHAdeMO fast charger, ABB PCS DCFC fast charger, with rating of 50kW (125A DC) is investigated. The scope is on the whole system: electric grid, converter and battery with focus on how charging is affected by battery state of charge (SOC), temperature and ambient temperature. A comparison between fast charging with DC and normal charging with 10A AC is also performed. The output current is limited of the battery temperature during fast charging. Below approximately 10C the charging current is 25A and between approximately 10 to 20C the charging current is 50A, above 20C at rated current of 125A is used. The efficiency of the fast charger is 90% at 50kW DC and decreases to 50% at 2kW DC. The efficiency of AC charging, using the on-board charger, is approximately 95% and the charging time is 8h instead of 1.5h with DC charging. Using the fast charger to charge the battery to 80% and then use AC charging is suggested as a charging strategy in coming standards. The fast charger impact the electric grid by causing a 10V voltage dip at full power (50kW DC) but reduces low order harmonics when operating. At standby the fast charger consumes 400W, corresponding to fully charge 219 batteries of 16kWh in a year. The option to use the charger as a STATCOM or filter even when no car is connected in order to improve power quality is suggested.