Sampling full digitalization current type PID (Proportion Integration Differentiation) control method and control circuit

Abstract

The invention provides a sampling full digitalization current type PID (Proportion Integration Differentiation) control method and a control circuit. The control method comprises the following steps of: acquiring a fixed given signal and a switch transformer primary side current sampling feedback signal through an encoder and a current sampling unit; sending the signals to a current type PWM (Pulse-Width Modulation) control chip so as to carry out PID control operation and obtain a duty ratio pulse width signal; and carrying out transform processing on data of welding current, voltage, power according to the duty ratio pulse width signal, so as to realize control on actual output of a welding machine. According to the control method, the detected data is processed, different PD control is adopted in different error ranges, and integrals are separated, so that a power supply can quickly follow and response, a welding process is controllable, impact current generated in short circuit is inhibited, and the work performances are stable and reliable; and in addition, a hardware circuit of PWM is effectively simplified, the cost is reduced, the dynamic response is quicker, the control response speed and the welding performance of the welding machine are improved, the work is more reliable, and the problem of higher current spike when an IGBT (Insulated Gate Bipolar Transistor) is opened is solved.

Description

technical field [0001] The invention belongs to the technical field of arc-dimensional control, and in particular relates to a sampling all-digital current-type PID control method and a control circuit. Background technique [0002] At present, a few welding equipment manufacturers in my country also have digital welding power sources, but most of them only use single-chip technology for man-machine interface, and there is no digital control at all. It can be said that MUC and DSP digital processing technology can be used for arc welding process control. It is rare, and lacks real welding process expert system, welding process data collection and analysis, welding model establishment and algorithm theory support, and the technical level is still at a low level. In the future, my country's welding industry will gradually integrate with international standards, develop in the direction of reverse change, automation, specialization, and digitalization, and further adapt to the n...

AI Technical Summary

Problems solved by technology

[0002] At present, a few welding equipment manufacturers in my country also have digital welding power sources, but most of them only use single-chip technology for man-machine interface, and there is no digital control at all. It can be said that MUC and DSP digital processing technology can be used for arc welding process control. It is rare, and lacks a real welding process expert system, welding process data collection and analysis, welding model establishment and algorithm theory support, and the technical level is still at a low level

Images