1、 The development process of servo system

The development of servo systems has gone through a process from hydraulic to electrical. Electrical servo systems are divided into direct current (DC) and alternating current (AC) servo systems based on the type of motor they drive. In the 1950s, brushless motors and DC motors were commercialized and widely used in computer peripheral equipment. In the 1970s, they entered their heyday of development. However, due to the defects of DC servo, such as complex structure and difficult maintenance, it is easy to overheat during operation. In high temperature environments, it is also difficult for other machines connected to it to master accuracy. In places with high speed requirements and large capacity, they cannot be used. In DC servo drive, mechanical commutators become a limiting factor.

The execution components of the system are generally ordinary three-phase squirrel cage asynchronous motors, and the power conversion devices usually use intelligent power module IPM. In order to improve the static and dynamic capabilities of the system, closed-loop control based on speed and position can be used. Three phase AC can effectively address the problem of slow inverter current response time and limit transient current to achieve stable operation of IPM. The speed and position loops can be controlled by a microcontroller to achieve the desired control performance.

Due to certain limitations, the development situation is constrained. DC servo still has structural defects and is difficult to inspect and repair. During operation, the temperature between the servo and the connected machinery may be affected, making it difficult to use in large-scale and high-speed situations. In terms of driving, mechanical commutators are an important limiting factor.

For the defects of DC servo, AC servo motor has some remedies. In terms of commutator and brush, especially in the case of excessive load on AC servo, it can improve the control ability of AC servo. Therefore, AC servo, as an important system, is widely used, involved in many aspects, and has a wide range of applications.