Detailed Explanation of the Key Technologies to Realize the EV Quick Charging

As the number of electric vehicles (EV) increases, there is a growing need to create more energy-efficient charging infrastructure systems that can be used to charge vehicles more quickly. Compared with the previous EVs, the new EVs have higher driving range and larger battery capacity, so it is necessary to develop EV quick chargers to meet the requirements of fast charging. Now, a 150 kW or 200 kW charging station will take about 30 minutes to charge an electric car to 80%, and the vehicle can travel about 250 km. According to the joint charging system and the CHADEMO standard, fast DC charging station can provide the power that is up to 400 kW.

At present, AG Electrical is working on the semiconductor technology that powers the electric charger faster, safer and more efficient.

High-voltage semiconductor switches (insulated-gate bipolar transistors [IGBT] and silicon carbide [SiC]) are driving the bus voltage (800 V or 1,000 V) in the system. As the system voltage increases, the requirements for isolation technology are also increasing so as to ensure the overall safety and reliability.

As power converters can achieve faster switching frequencies (from a few hundred Hertz to a few megahertz), the size of magnetic components and other passive components used in the circuit will be reduced at these high frequencies, thereby reducing system costs and increasing overall power density. Therefore, high bandwidth current and voltage sensing are required to accurately control and protect the digital power level.

Higher efficiencies require the use of multiple complex power levels, which in turn require high voltage isolated gate drivers to effectively switch these power levels and reduce overall switching losses, as well as enhance the isolation and short-circuit protection.

High power density, reliability, and robustness are becoming increasingly important in the power converters used in EV quick charger. As power and voltage levels increase, it is critical to protect personnel and equipment from hazardous operating conditions.

Manufacturers targeting at chargers with high power density and high efficiency will use IGBT, SiC and GaN based power converters, and their switching frequencies range from a few hundred Hertz to a few megahertz. High-frequency current and voltage sensors are critical to the development of these platforms.

Smart gate driver technology will meet the requirements of the necessary high voltage levels, fast switching speeds, and fast protection. Given the leaps and bounds in semiconductor technology over the past decade, the new EV quick chargers, which can allow you to fully charge your EV during a short break, will soon be available.