[Editor's Note] According to data from the Korea Automobile Research Institute, global electric vehicle new car sales in 2021 were approximately 4.72 million units, up 112% year-on-year, accounting for 5.8% of total vehicle sales. As the popularity of electric vehicles increases, interest in batteries and charging has naturally increased. Among electric vehicle charging technologies, onboard chargers manage the flow of electricity between the power grid and the battery. Since onboard chargers are permanently installed in vehicles and are directly related to electric vehicle performance, they are also very important in terms of system solutions. Our magazine met with Infineon's Vice President Lee Cheol to learn about the principles and advantages of onboard chargers and to hear about Infineon's onboard charger system solutions.
■ What is an Onboard Charger (OBC) and how does it work?
An on-board charger (OBC) is the main battery charger installed in an electric vehicle.
Electric vehicles, unlike internal combustion engine vehicles, use electric energy stored in batteries instead of fossil fuels as their energy source, which requires repeated battery charging.
Since the battery is a type of capacitor bank, it needs to be charged with a DC power source. The PFC stage of the onboard charger converts the AC input power into a constant DC voltage, and the DC-DC converter stage converts this DC voltage to match the battery voltage level and charges the battery.
■ I am curious about the features and advantages of the onboard charger.
Electricity produced by power plants is usually alternating current, and most of the power sources we have access to in our daily lives are alternating current.
Onboard chargers, unlike DC chargers, use AC power. Because it is input, it has the advantages of excellent accessibility for charging, reasonable cost, and reduced weight and size.
Electric vehicles are equipped with high-capacity batteries and are called “mobile energy sources” beyond just a simple means of transportation.
The bidirectional onboard charger can convert the electric energy stored in the car battery back into AC power, which can be used for outdoor activities such as camping, as a means of supplying power during power outages, charging other electric vehicles, and even contributing to the realization of a smart grid by connecting to the power grid.
■ What are the development trends of onboard chargers?
Onboard chargers must not only satisfy the charging function of simply converting power from AC to DC, but also satisfy various requirements depending on the car manufacturer, launch region, and usage conditions.
Among the various development requirements, there are four common trends: △high charging power △high power density △high output voltage △bidirectional power conversion.
■ I am curious about Infineon’s OBC system solution.
Infineon has a broad product portfolio covering power, sensors, communications and security products from high to low power.
Infineon not only provides high-power switching elements required for the power block of the onboard charger, but also △gate driver ICs that can drive these power switching elements, △microcontrollers for digital control, and △internal and externalIt provides a total solution for developing an onboard charger system, including a CAN transceiver for secondary communication, power supply ICs such as LDO, PMIC, and SBC (system basis chip) for internal power supply of the system, and current sensing IC.
■ Please explain Infineon’s power switching solutions.
Infineon offers optimal power switching solutions to meet the latest development trends in onboard chargers.
Infineon's power switching solutions include: silicon-based IGBTs and MOSFETs; wide-bandgap devices such as SiC diodes; SiC MOSFETs; and GaN.
In terms of packaging, we also provide discrete solutions including through-hole packages such as TO-247, SMD packages such as D2PAK, and module solutions such as EasyPACK.
In particular, Infineon's power switching devices for battlefield applications not only have best-in-class performance, but also meet a higher quality level than AEC-Q101, the international standard for automotive semiconductors.
■ Please say a word to your readers.
According to market research firms, one of the biggest concerns consumers have when purchasing electric vehicles is charging.
Infineon offers complete and comprehensive power switching solutions for the development of onboard chargers for electric vehicles.
/> With Infineon's onboard charger solutions, we hope to respond to the latest development trends and develop onboard charger systems that meet each design requirement.
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