In the surface-mounted permanent magnet synchronous motor speed control system, the problems of large overshoot, poor robustness and susceptibility to load disturbance in classic PI control are addressed. A controller based on the second-order sliding mode algorithm was designed. The integral sliding mode surface was adopted. The convergence in finite time was proved by Lyapunov function, and it was applied to the speed control. It is insensitive to the change of internal parameters Aiming at the problem of load disturbance, a load torque observer was designed to compensate the observed value of the load torque into the current to reduce the influence of the load disturbance on the system. Simulation and experimental results show that the control method improves the speed regulation system of the permanent magnet synchronous motor significantly, can respond quickly to a given speed without overshoot, and it has strong robustness

Lightweight and miniaturized are important development directions for motor design, such as aerospace application motors, automotive motors, drone motors, medical equipment motors, etc., which have high requirements for the weight and volume of motors. In order to achieve the goal of lightweighting and miniaturization of motors, that is, to reduce the weight and volume of motors per unit power, motor design engineers need to optimize the design process, apply advanced technology and high-quality materials. Due to the conductivity of copper being about 40% higher than aluminum, the proportion of copper iron application needs to be increased. For cast aluminum rotors, it can be changed to cast copper, and for motor iron cores and magnets, higher level materials are also required, greatly improving their conductivity and magnetic properties. However, after optimization, the cost of motor materials will increase. In addition, for miniaturized motors, there are higher requirements for production processes.

With the continuous improvement of the world's equipment manufacturing industry, industrial and agricultural product production, and other development directions towards action accuracy, control accuracy, action speed, and information accuracy, it is required that the motor drive system must have multiple functions such as self judgment, self-protection, self speed regulation, 5G+remote control, etc. Therefore, intelligent motors will definitely be an important development trend in the future. POWER company should pay special attention to the research and development of intelligent motors in its future development. In recent years, we have seen various applications of smart motors, especially during the epidemic period. Smart devices have played an important role in our fight against the epidemic, such as intelligent robots detecting body temperature, intelligent robots delivering goods, and intelligent robots judging the epidemic situation.

With the continuous progress of society, the continuous development of high technology (especially the application of AI technology), and people's constant pursuit of a better life, the application of micro motors is becoming increasingly widespread. For example, the home appliance industry, automotive industry, office furniture, medical industry, military industry, modern agriculture (planting, breeding, warehousing), logistics and other fields are all developing towards automation and intelligence to replace labor, so the application of motors is constantly expanding.