Impact of EV battery Impact of EV battery
Impact of EV battery chargers on the power quality of distributionsystems
A summary of the actual state of battery charger harmonics ispresented. The effect of harmonic distortion on the distributionsystem, especially on distribution transformers, is analyzed. Aprogram was developed, which allows the consideration of thetransformer life consumption as function of the battery chargercharacteristics and charging algorithm. The program is considered adistribution planning and management tool. The proposed tool can beeasily applied to determine the optimum chargingtime as function ofthe existing load, ambient temperature, and time of day. From thestudy, it can be deduced that direct connect-and-charge scheme canbe detrimental to the transformer life, especially under hightemperature and large load. Calculations show the existence of aquadratic relationship between the transformer life consumption andthe total harmonic distortion (THD) of the battery charger current.Furthermore, the current THD should be limited to 25-30% in orderto have a reasonable transformer life expectancy.
IEEE Transactions on Power Delivery
batterypowered vehicles; battery chargers; power supply quality; powersystem harmonics; power transformers; harmonic distortion; powerdistribution planning; EV battery chargers; power quality;distribution systems; battery charger harmonics;harmo