An Overview of Power Electronics in EVs

Article By : Abhishek Jadhav

High efficiency and high reliability are two key characteristics that facilitate the analysis and design of power-electronic systems.

In the evolving market for power-electronic semiconductor devices, there have been increased research initiatives to solve the complex issue of introducing no loss and achieving near-perfect reliability. High efficiency and high reliability are two key characteristics that facilitate the analysis and design of power-electronic systems. The hardware devices are designed with very few special types of power semiconductors, and choosing the right one is a complicated task.

Silicon carbide has now become an alternative to silicon-based electronic components, mainly because of the wide-bandgap applications. SiC has the combined characteristics of greater power efficiency, smaller size, lighter weight, and reduced overall cost of the system. In the past decade, SiC has been the semiconductor material with more potential to be deployed in advanced power system applications. The material has been found in applications in diesel engines, electronic circuitry, and high-temperature conversion systems.

When it comes to a sustainable future, manufacturers and designers are always looking for environmentally friendly materials for advanced power-electronic systems. Even in this space of concern, SiC is the key to a sustainable energy future, as it offers all the required advantages for devices used in data center power supplies, wind and solar power modules, and even electric-vehicle drive converters. SiC possesses increased efficiency of power conversion, withstands high voltages and current, and operates at higher temperatures.

SiC drives the future of EVs

SiC is actively being researched and developed to become a more reliable and robust material to meet the continuing demand and growth of power applications. One of the leading electronic device manufacturers, STMicroelectronics, is working on developing SiC products to comply with the highest standards of reliability, performance, and efficiency gains for EV applications, solar inverters, energy storage, industrial motor drivers, and power supplies. However, the company is more focused on providing quality power-electronic devices for the electric automotive industry.

An Overview of Power Electronics in EVs
SiC in industrial applications

Last year, STMicroelectronics introduced the third generation of its STPower SiC MOSFET as its most advanced state-of-the-art power device for EV powertrains. When EV manufacturers are adopting 800-V drive systems to achieve much faster charging and reduce EV weight, STMicroelectronics’ new SiC devices are optimized for these high-end automotive applications, such as EV traction inverters, on-board chargers, and DC/DC converters.

“We continue to drive this exciting technology forward with innovations at both the device and package levels,” said Edoardo Merli, Power Transistor Macro-Division general manager and group vice president of STMicroelectronics’ Automotive and Discrete Group. “As a fully integrated SiC products manufacturer, we are able to deliver continued improved performance to our customers. We are investing relentlessly to support our automotive and industrial programs expected to generate $1 billion in SiC revenue in 2024.”

Another manufacturer at the top of the list is onsemi, which has also been working on launching automotive-grade SiC-based power modules for on-board chargers. These power devices use a transfer-molded package to increase efficiency and shorten charge time for all types of EVs and are specifically designed for high-power on-board chargers. Onsemi modules demonstrate low conduction and switching losses when combined with best-in-class thermal resistance and high-voltage isolation, becoming an ideal choice for EV manufacturers.

GaN for EV chips

Gallium nitride technology is on its way to support electric and hybrid vehicles to charge faster and driver farther. GaN is a versatile semiconductor material that demonstrates the capability to operate at high temperatures and voltages, which is a key concern for power management applications. GaN allows car manufacturers to achieve more reliable operations for EV on-board charging systems.

Texas Instruments (TI) is one of the key suppliers of GaN products with efficient use in achieving new levels of power density for the automotive industry. TI has an advantage on GaN technology over SiC, which generates significant heat during the charging process and increases charging time. TI’s GaN technology has fast switching speed to increase efficiency, which in turn reduces the burden on cooling in EVs. This further reduces the overall system cost and increases power density as heavy magnetics around the power supply become smaller. The end result is reduction in EV weight and increased vehicle range to become another promising semiconductor material for power management systems.

An Overview of Power Electronics in EVs
EV at a charging station

“Our customers are looking for ways to add more power without drastically increasing the vehicle weight or cost,” said Steve Lambouses, who leads the high-voltage power team at Texas Instruments. “TI’s highly integrated GaN solution gives automotive designers the ability to develop charging systems that are more dependable, are more affordable, and use power much more efficiently.”

STMicroelectronics is also contributing toward the expansion and development of GaN technology with its wide range of products targeting applications from power supplies and adapters to power-factor correction and DC/DC converters. STMicroelectronics started a new smart power initiative based on GaN technology: STi2GaN, a solution based on wide-bandgap semiconductors for a sustainable power system. STi2GaN is a family of GaN-based products that enable engineers to get most of the new semiconductor material with its higher level of integration and performance. Combining these advantages, the manufacturers serve a variety of power applications that will benefit from the smaller size, improved performance, and reduced costs.

Conclusion

Power-electronics designers are waiting for breakthrough technologies to redesign circuits and boost the efficiency of energy-conversion systems. SiC and GaN match these requirements and expectations to become a promising candidate for power-electronic designs. SiC devices have been deployed in power systems inside EVs to provide significant efficiency gains in charging stations. They offer several advantages for EVs, such as over 600 km of driving range, 150 to 200 kg less weight of an average EV, double the energy from a charging station, and longer battery lifetime due to lower stress.

Developing integrated GaN technology is one example of how semiconductor electronic device manufacturers are innovating for a secure and sustainable future. With each generation of semiconductor material, these companies build on the previous technology for a more efficient, reliable, and affordable breakthrough. The future of sustainability lies in the hands of semiconductor power devices for EVs.

 

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