The driving power of new energy automobiles, especially energy automobile of class B and above, is generally above 180kW, and two or more sets of electric drive systems need to be equipped. As the proportion of high-end electric automobiles continues to increase, the installed capacity of new energy driving motors will further increase. With the advantages of high power density, low energy consumption, small size, and light weight, permanent magnet synchronous motors are the most widely used in China's new energy automobiles, accounting for 94.4% of the total installed capacity in 2021. Driving motor is one of the three core components of new energy automobiles, and its future development direction is high speed and high power. This requires the motor to reduce the volume, weight and iron loss of the motor as much as possible under the same power. But reducing the volume and weight of the motor will lead to a reduction in the torque of the motor, so the speed of the motor needs to be increased. For example, the speed of the Prius2015 motor is almost three times that of the Prius2004 motor, while the peak torque shows a decreasing trend. Through the cooperation of the high-speed motor and the gearbox, the high-speed low-torque input is transformed into a low-speed high-torque output, thereby achieving the purpose of driving new energy vehicles.

The high-speed and high-power driving motors also put forward higher requirements for motor materials, especially the stator and rotor cores made of laminated non-oriented silicon steel sheets, which not only directly determine the motor power, torque, iron consumption, temperature The upgrade also affects the cruising range of new energy vehicles. For example, the Nissan Leaf II, which was launched in Japan, North America, and Europe in 2018, has a battery capacity of only 40kWh, but a cruising range of up to 400km, which is the same as the Tesla Model S with a battery capacity of 60kWh. This is because Nissan Leaf II uses a permanent magnet synchronous motor as the driving motor, which is excited by permanent magnets and does not require excitation current, so there is no excitation loss, low loss, and high efficiency. In addition, the stator and rotor iron core of the Nissan Leaf II driving motor is made of laminated silicon steel sheets with a thickness of 0.25mm, which can reduce iron loss and further improve motor efficiency. The driving motor core of the 2016 BMW i3 is made of laminated silicon steel sheets with a thickness of 0.27mm. There are a large number of weight-reducing holes in the rotor core to reduce the weight of the motor and increase the power density of the motor. Therefore, in order to improve the efficiency and power density of the motor, the silicon steel sheet for the motor has been reduced from the traditional 0.35mm and 0.50mm to 0.25mm and 0.27mm. It is foreseeable that with the increase of motor speed, silicon steel with thinner specifications and lower iron loss will be gradually applied to new energy vehicle driving motors.