TI helps electric vehicles achieve comprehensive powertrain integration

Today, the average production cost of an electric vehicle is $12,000 higher than a traditional internal combustion engine vehicle, according to a McKinsey report. As automakers work to meet global emissions regulations, they must also bridge the price-performance gap to help consumers transition to hybrid or fully electric vehicles.

Therefore, it is undoubtedly a huge challenge for automotive design engineers to improve efficiency, reliability, extend driving range, and reduce the cost of expensive components (powertrain systems) of electric vehicles. In response to the current situation and challenges of the industry, Texas Instruments (TI) has proposed a variety of power level "all-in-one" integration solutions and design ideas to help new energy vehicle companies enhance their technological advantages.

Hybrid and electric vehicle powertrains have always been a combination of systems that drive progress in the automotive industry, packaging batteries, DC/DC converters, onboard chargers, and traction inverters in different housings. Currently, with advances in analog and embedded processing technology, designers can combine these systems using a single domain controller and power stage, helping them improve efficiency and reliability while reducing costs and complying with functional safety standards, which has become a popular research direction.

Zhou Dongbao, Field Technical Application Manager of the Automotive Business Unit of Texas Instruments China, introduced that according to the number of integrated modules, it can be divided into two-in-one, three-in-one, five-in-one and other different integrated solutions. According to the difficulty of integration, powertrain integration can also be divided into basic mechanical level integration, that is, physical integration, and more complex control logic and power level integration. By using TI's solutions, customers can achieve a solution transition from a distributed power architecture to a single power domain controller. The complexity of the entire system will also increase with the increase in the level of integration, and the benefits to customers will also increase. However, the higher the integration, the more challenges will be faced.

Regarding the integrated solution, Zhou Dongbao summarized: (1) The all-in-one integrated solution of the electric drive system reduces the number of connectors by sharing the coupling of the shell and the cooling system; (2) By further sharing the control circuit and the power circuit, the volume, weight and cost of the electric drive system are effectively reduced, while the power density of the electric drive system is improved; (3) Better lightweighting helps to extend the range of electric vehicles; (4) By optimizing the thermal performance of the system as a whole, the reliability of the system is guaranteed. At the same time, because functional safety is a very important design indicator in the current electric drive system, TI's integrated solution also helps to simplify the development and certification of functional safety systems.

The "all-in-one" integrated design solution at the power electronics level can help customers reduce the size and cost of the entire system by 50%. TI's three-in-one powertrain integration solution uses products such as the C2000 series microcontroller, GaN field-effect transistor with integrated driver, isolated driver UCC5870, and temperature sensor TMP126.

In addition to the inherent advantages of integrated systems, ensuring reliability in the high-voltage battery environment of electric vehicles requires robust protection features and peak thermal performance.

Isolation technology can help address these challenges with isolated gate drivers and modulators designed and tested for the harsh automotive environment. Integrated diagnostics are also an important part of the safety equation, helping the powertrain system meet ASIL-D requirements, the highest level of functional safety requirements for road motor vehicles and a major challenge for OEMs.

Zhou Dongbao summarized the advantages of TI's powertrain system integration solution: First, the integrated solution has high power density and the efficiency of the entire system can reach 98%; second, by using TI products, it helps customers optimize thermal performance, as well as circuit design such as diagnosis and protection, to improve the reliability of the entire circuit; third, by using TI products, the cost of the entire system can be greatly reduced by using fewer devices, smaller solutions and sizes; fourth, TI provides a variety of solutions to simplify customers' functional safety certification, such as compliance certification up to ASIL D.

At a media sharing meeting held by TI, Han Yongjie, vice president of VMAX, said, "In recent years, the new energy vehicle industry has developed very rapidly. Driven by new energy vehicles, power electronics has two very obvious trends in the development of electric vehicles. One is to improve performance, and the other is to reduce costs and reduce product size and variety."

In his opinion, powertrain integration is the key to designing electric vehicles that are more efficient, reliable and affordable for consumers across China. TI's technology and expertise are helping us achieve the level of integration that customers require for onboard chargers, DC/DC converters and traction inverter systems. Companies and industries are experiencing the advantages of powertrain integration firsthand. In terms of future trends, Han Yongjie believes that the entire power system will move toward further integration.

Final Thoughts

The electric vehicle market is growing rapidly. It is expected that by 2025, the number of electric vehicles will account for 30% of global car sales. Powertrain integration will play a key role in the growth of the electric vehicle market, and the development of integration continues from low-level mechanical integration to high-level electronic integration. It has been proven that the power density of integrated powertrain systems has increased by 40% to 50%, the volume and weight have been greatly reduced, and the reliability has been improved. Powertrain integration is supporting the accelerated growth of the electric vehicle market.

However, as the level of integration increases, the complexity of the system will also increase. Each architecture variant will bring different design challenges, and flexibility will become a key consideration for powertrain integration.