The challenges facing the future development of China's drive motors
The vehicle drive motor is the core key component of the electric vehicle power system, and its performance directly affects the vehicle's overall vehicle performance. After more than ten years of development, China has made great progress in the technology, products and industries of vehicle drive motors. China has independently developed a series of drive motor system products that meet the needs of various types of electric vehicles, and has obtained a large number of relevant intellectual property rights for drive motor systems, forming a batch production capacity.
China's self-developed permanent magnet synchronous motor, AC asynchronous motor and switched reluctance motor have been realized with small and medium-sized batches of domestic vehicle manufacturers. The power range of the product covers the power demand of the whole vehicle below 200kW, and the main performance indicators of the drive motor system. To reach the international advanced level of the same power level, the products of some enterprises have gone abroad.
At the same time, companies that provide new energy vehicle drive systems based in the United States, Europe and Japan are developing rapidly, making great progress in reducing motor production costs, improving motor efficiency, and integrating motor and engine design. Improvement and continuous improvement of supporting capabilities have also brought many challenges to the future development of China's drive motors.
1. Improve the power density of permanent magnet motor
In order to make the electric motor of the electric vehicle more compact and have higher output power, after years of practice in the world, it is inevitable to use rare earth permanent magnet as the magnetic material of the motor from the viewpoint of improving power density and torque density. With the popularity of electric vehicles, the market is in desperate need of high-performance motors that use rare earth permanent magnet materials. Since most of the rare earths are produced in China and the reserves are also the first in the world, China has obvious resource advantages in the permanent magnet motors for vehicles. In recent years, China has listed rare earth elements as strategic resources and imposed strict export restrictions, which directly led to Japan’s concern about rare earth materials permanent magnet motors. In Japan’s “Next Generation Automotive Strategy 2010”, research and development has been proposed. Motor technology that replaces rare earth permanent magnet raw materials. The United States is also looking for alternatives to rare earth permanent magnets in its next-generation power electronics technology program, but no good solution has yet been found.
2. Broaden the feedback brake high efficiency zone
Similar to the transmission fuel engine car configuration gearbox to expand the engine working range, the electric drive system is also implementing the adjustment of the motor working range by continuously introducing the shifting structure, so that the two can work better in the more efficient area. Feedback braking is a basic feature of hybrid mechatronics technology. With the increase in the degree of mixing requirements, the corresponding demand for feedback braking range will also increase. By using the motor of the college, the appropriate shifting system and the control strategy, the allowable range of the feedback brake can be adapted to more working conditions, so that the energy saving of the whole vehicle is more effective and the driving range is extended.