In the process of using and debugging the servo system, there will be all kinds of unexpected interference from time to time, especially for the application of pulse servo motor. The following analyzes the types and ways of interference from several aspects, so as to achieve the purpose of targeted anti-interference, hoping to study  together.

1. Interference from power supply

Practice has proved that there are many servo control system failures caused by the interference of power supply, which are generally solved by pressurizer, isolation transformer and other equipment.

3. Interference from disordered grounding system

As we all know, grounding is one of the effective means to improve the anti-interference of electronic equipment. The correct grounding can inhibit the external interference of the equipment, but the wrong grounding will introduce serious interference signals, making the system unable to work normally.

Generally speaking, the ground wire of the control system includes system ground, shield ground, AC ground and protective ground. If the grounding system is in disorder, the main interference to the servo system is that the potential distribution of each grounding point is uneven, and there is a ground potential difference between different grounding points, which causes the current in the ground loop and affects the normal operation of the system.

For example, if both ends a and B of the cable shielding layer are grounded, there is a ground potential difference and current flows through the shielding layer. When there is an abnormal state such as lightning, the ground current will be greater. In addition, the shielding layer, ground wire and the earth may form a closed loop. Under the action of the changing magnetic field, the induced current will appear in the shielding layer and interfere with the signal loop.

If the system grounding is confused with other grounding, the ground circulating current may produce unequal potential distribution on the ground wire, which will affect the normal operation of the servo circuit. The key to solve this kind of interference is to distinguish the grounding mode and provide good grounding performance for the system.

Interference from inside the system

It is mainly caused by mutual electromagnetic radiation between components and circuits in the system, such as mutual radiation between logic circuits, mutual influence between analog ground and logic ground, and mutual mismatch between components.

The actual site conditions are much more complex, can only be specific analysis of specific problems, but ultimately there will be a satisfactory solution, just the process experience is different!