Development and Prospect of Electric Drive System of New Energy Vehicles

In the 21st century, driven by national policies and environmental protection needs, new energy vehicles have become a hot object of industry and capital. Unlike traditional vehicles, the most important core system in new energy vehicles has changed from an internal combustion engine to an electric drive system.

On May 19, 2015, the State Council officially issued “Made in China 2025”, which proposed the technical roadmap of key areas: electric drive system technology, breakthroughs in motor and transmission, inverter integration and high-integration electric drive system dedicated transmission and other technical problems.

In 2017, the Ministry of Industry and Information Technology, the Ministry of Science and Technology, and the National Development and Reform Commission jointly issued the “Mid- and Long-Term Development Plan for the Automotive Industry”.

In “Breakthrough in Key Areas and Leading Industrial Transformation and Upgrading”, it emphasized the deployment of tasks in 6 innovation chains including motor drive and power electronic assembly. . It can be seen that the electric drive system will become an important benchmark for competition among new energy vehicle companies.

Development Status of Electric Drive System at Home and Abroad

Foreign mainstream pure electric car companies, such as GM, Volkswagen, Renault, Tesla, Nissan, etc., have all carried out the development and application of electric drive systems. Representative models include BOLT II, E-GOLF, ZOE II, Model S, LEAF second generation and so on. Foreign car companies mainly adopt the method of self-integrated design of electric drive systems, but the components are mostly supported by the supplier system.

Domestic auto companies have also carried out relevant research, with integrated electric drive systems as the main direction, outstanding representatives include Changan, BYD, SAIC Motor, Geely, etc.

Changan EV460 rides on its own 100kW three-in-one electric drive system

At the same time, major foreign auto parts giants are aiming at the electric drive system market and are racing to launch products. Continental, BOSCH, ZF, MAGNA, Valeo Siemens, etc. have all launched 70~150kW electric drive systems in the Chinese market and won orders from domestic OEMs.

The electric drive system of a foreign component manufacturer

Domestic component companies are not far behind in terms of integrated electric drive systems, including Shanghai Electric Drive, Beijing Jingjin, China CRRC, etc., all launched two-in-one or three-in-one electric drive systems during the same period.

Trend analysis

♦ Integrated integration

The electric drive system includes a motor, a reducer and a motor controller. The previous split-type electric drive system has the disadvantages of large volume, low efficiency and high cost. In the next 3-5 years, the three-in-one integrated electric drive system will become the mainstream.

Foreign integrated electric drive systems will focus on mass production in the next 2 to 3 years and enter the Chinese market substantially, which will have a big impact on the domestic electric drive market. This impact is not only reflected in technology and price, but also in market annexation and corporate alliances.

♦ High-speed motor

At present, the maximum speed of the motor of electric drive products on the market is about 12000rpm. However, with the development of motor technology and consumers’ pursuit of driving experience and driving efficiency, higher-speed motors will become inevitable. Motors with more than 15000rpm have been partially listed, and are gradually applied in some high-positioned models, such as the Tesla series, Weilai ES8, etc.

♦ The large speed ratio of the reducer

The rise of electric vehicles in the Chinese market has lowered the threshold for OEMs to master speed reducers to some extent. Due to the difference between the motor and the traditional internal combustion engine, the electric vehicle can use a single-speed reducer to ensure the effective use of the motor in a large speed range.

The speed ratio of the existing electric vehicle reducer is usually about 10. However, as the motor speed becomes higher and higher, the speed ratio of the reducer will reach more than 15. At this time, the single-speed ratio reducer will be more and more unable to meet the needs of the market. Therefore, a large speed ratio, two-speed or multi-speed reducer will become the development direction of the future electric drive system reducer.

♦ Application of new technology

The rapid development of new energy vehicles directly drives the innovation of upstream and downstream technologies; at the same time, breakthroughs in new technologies will also promote the upgrade of new energy vehicles. Reflected in the electric drive system, related new technologies include motor Pin winding technology, low-loss silicon steel technology, double-sided water-cooled IGBT, silicon carbide precision ceramics, etc.

Epilogue

Domestic new energy vehicle companies and parts companies are currently in a critical period of development.

On the one hand, traditional car companies are gradually transforming, vigorously developing electric vehicles, and striving to gain a firm foothold in the new market war; on the other hand, emerging new energy car companies have sprung up, absorbing a lot of social capital, trying to get a piece of the pie. , there is a lot of momentum. But behind the prosperity, is the collapse of the core technology.

Among domestic car companies, there are not many companies that have mastered the independent design, independent integration and independent manufacturing capabilities of electric drive systems.

Many Internet car manufacturers have “finished” the shortcomings of electric drive systems through outsourcing and outsourcing, but they will inevitably be at a disadvantage in the long-term market competition.

In addition, the core components (such as IGBTs, etc.) in the electric drive system are still in the hands of foreign oligarchs (such as Fuji and Infineon). Domestic auto companies should fully realize the importance of key technologies and master the core technologies independently. Determine their respective seats in the new energy market pattern.