Growing prizes of fossil fuels, environmental issues and bigger capacity accumulators transform the way of transportation.

International Electrotechnical Commission (IEC) has developed a standard IEC61851, which classifies charging stations into 3 categories. Level three charging stations are publicly used fast charging stations with maximum charging power 50 to 240 kW, witch can charge the electric vehicle batteries to 80 % level within 15 minutes and to a 100 % level within 30 minutes. Due to high energy demand and needed high input currents a fast charging stations are placed near to the substation that contains low frequency transformer. Inside the fast charging station intermediate DC-bus connects energy storages, supply grid rectifier and charging converters. Low voltage (570 V) causes high currents and results in high losses at busbars, magnetic components and semiconductor devices. Due to electric safety regulations galvanic isolation transformers are used in charging converters thus the component count is increased along with equipment cost and power losses in additional transformers and energy conversion stages.

The problems in state of-the art electric vehicle fast charging stations are:

1. low frequency sub-station transformer;
2. additional energy losses due to many energy conversion states;
3. separate isolation transformers in each charging converter;
4. low intermediate DC-bus voltage (high conduction losses).