Overview of AC or DC converters for fast charging stations

The point of an AC/DC converter is that the outlet primarily provides AC power, while the EV battery uses DC power to charge the battery. Therefore, there is a need for an AC/DC converter for converting AC power to DC power. It is also a major component of EV battery chargers and acts as an input current shaper for power factor correction and harmonic reduction.

Since rechargeable batteries are what power electric vehicles to run, it is important to understand some of the parameters of the charging station. Most of the basic parameters such as power efficiency, compact architecture and fast charging will determine the overall productivity of the target charging station.

Electric vehicle charging stations are divided into level II and level III.

Level I forms part of the smaller battery sizes. Level I charging time is approximately 8 to 10 hours; however, this may vary depending on the energy capacity of the battery. It only uses AC charging and has an onboard charger since the charging components are inside the EV.

Level II charging time is approximately half that of Level I. Additionally, Level III fast charging stations use an external charger (not on board) to provide high voltage.

It can charge an electric vehicle in as little as 20 to 30 minutes, while a Level II charging station can charge a vehicle in four to eight hours.

Typically a conventional AC/DC converter such as a 2L Voltage Source Converter (VSC) is used. The disadvantages of using these converters are that they have limited power ratings and high harmonic contamination. To avoid these disadvantages, hybrid filters are used, but these filters also increase the cost of the system. These converters also have undesirably high switching frequencies. In high-power applications, switches are subject to large voltages and currents and are limited by existing technology in semiconductor devices.

Typically a conventional AC/DC converter such as a 2L Voltage Source Converter (VSC) is used. The disadvantages of using these converters are that they have limited power ratings and high harmonic contamination. To avoid these disadvantages, hybrid filters are used, but these filters also increase the cost of the system. These converters also have undesirably high switching frequencies. In high-power applications, switches are subject to large voltages and currents and are limited by existing technology in semiconductor devices.