U.S. Develops New Generation of Electric Vehicle Charger to Adjust Charging Power According to Electricity Demand

The second-generation, second-class electric vehicle charger, which can adjust the charging power based on the power supply status of the charging grid, is being tested at a charging station in Detroit, USA.

The smart charging project was funded by the US Department of Energy's two million US dollars. The participants consisted of Delta, Detroit DTE Energy, Mercedes-Benz North American R & D Center, and consulting firm kVA. The three-year project has entered the final stage.

The second-generation AC level 2 charging device designed and manufactured by Delta can use the site management system software developed by Delta to wirelessly communicate information with the grid of the charging site. This first set of charging system can adjust the charging power for electric vehicles based on the electricity demand of the charging site. The size of the charging power is determined by the information collected by the Delta dedicated instrument.

Charles Zhu, Delta's automotive business director, said: "When the available power of the charging station is greater than the total demand of the vehicle being charged, normal charging can be maintained. When the available power of the charging station is insufficient, the charging equipment will temporarily reduce the charging power until the charging station. The supply of power grids has returned to normal levels."

For a charging station composed of multiple charging terminals (such as the one in Detroit), the system can optimize the charging power of each terminal based on the energy consumption of the entire charging station.

According to Hauker Asgeirsson, DTE Energy's engineering manager, a networked power smart management system can maximize the life of the transformer. He said: "In the summer, when the pressure on the power grid is greatest, the temperature of oil, copper, aluminum, and iron components filled inside the transformer will increase significantly, which will reduce the life of the transformer. Conversely, the nighttime electricity price is lower and the nighttime charging is more economical. But electric vehicles Charging at night is tricky because, as a result, the transformer heats up day and night and there is no time to cool it."

DTE and the engineering students at the University of Michigan worked together to assess the negative impact of electric vehicle night charging on transformer cooling conditions. Asgeirsson said: "According to model analysis and research, we have found that when more than 60% of the total charging terminals are charging electric vehicles at night, the life of the transformer will be shortened. However, there are currently not many users who are charging at night."

According to 2013 data from the IHS Automotive Database, in the United States, pure electric and plug-in hybrid vehicles each have a market share of 0.3%. Devin Lindsay, an automotive powertrain analyst at HIS, said: "In 2020, the United States and Europe will be the largest production areas for electric vehicles. Europe, China and North America will be the largest production areas for plug-in hybrids."

Delta’s first second-generation charging station is located on the sixth floor of the MGM Grand Hotel in Detroit, not far from DTE Energy. Delta's President, MS Huang, said: “In this charging station, we have placed a total of 24 Delta second-generation charging terminals. In the coming months, we will continue to collect user feedback from this charging station.”

The intelligent networked charging system means that infrastructure operators can actively manage the charging load during the peak hours of power usage, while users can also benefit from the price of the trough. Asgeirsson said: "With smart charging technology, we can accommodate more electric vehicles charging." Delta said that its level 2 intelligent networking charging device is the only North American market price under $ 450, and provides similar smart charging function products .