New energy vehicles and silicon steel
Judging from the material selection of new energy vehicle drive motor users in recent years, domestically used 0.35mm thickness in large quantities, but now gradually switch to 0.27-0.30mm thickness; Japan uses 0.25-0.30mm thickness, which has a negative impact on the iron loss and magnetic properties of the material. The comprehensive performance requirements of iron loss and strength are higher; European and American series tend to use 0.27-0.30mm and 0.25-0.30mm thickness respectively, and have the highest requirements on the iron loss and strength performance of the material.
New energy vehicle drive motors will develop towards higher speed and higher power density in the future. Therefore, the silicon steel sheets used in them will develop towards lower iron loss, higher magnetic induction, higher yield strength and thinner thickness. However, the thickness of silicon steel cannot be reduced infinitely. When the thickness is reduced to less than 0.25mm, the centrifugal force of the motor will be large under high-speed operation conditions, and the risk of fracture at the weak points of the core magnetic bridge will increase. Moreover, the thickness of high-grade silicon steel continues to decrease, making the production and processing of raw materials difficult and increasing costs, affecting the overall economics of the motor. Therefore, considering the manufacturing and processing costs, the thickness of 0.2-0.25mm should be the optimal thickness of silicon steel for new energy vehicle drive motors in the future.
In addition, the comprehensive mechanical and magnetic properties of the high-strength non-oriented silicon steel sheets currently used by Nippon Steel are inferior to those developed by Nippon Steel in the early days. This should be consistent with the current situation that most of Japan's new energy vehicles are hybrids, because hybrids The power requirements for drive motors are different from those of pure electric vehicles, especially in terms of range anxiety and temperature rise caused by high-speed operation at peak power. This is more likely due to the frequent accidents caused by Japan's small land and dense population. Typical urban road conditions such as start-stop and low-speed operation, as well as the fact that Japanese automobile companies invested heavily in hybrid power in the early stage, steel companies and automobile companies have chosen a temporary route to compete for profits, rather than a long-term technical route. Our country has a vast territory, rich topography, and huge climate differences between the north and the south. This results in our country's family cars usually having to drive long distances under various geographical and climatic conditions. Therefore, in the future development of pure electric vehicles in our country, in addition to attaching great importance to high-end The research and development of energy-density batteries and drive motors will eventually become as important as fuel vehicle engines to meet the needs of the people. In the end, the performance of batteries and motors will still be used as the main technical indicators to classify high-performance electric vehicle brands.
Our country is a major producer of industrial motors and exports a lot of them. The related industrial foundation is very good. However, most of our companies follow and imitate the product technologies of developed countries, and there are few leading product plans to prepare for a rainy day. Especially when high-performance pure electric vehicles have become indispensable. Reversing the future development trend, a technical route of non-oriented silicon steel sheets that are used for high-speed, high-power-density drive motors and have high strength, high magnetic induction and low high-frequency iron loss will be an inevitable choice in the future.