contravariant
With the commutation is two opposite concepts, commutation is the process of converting alternating current into direct current, and inverter is the process of changing direct current into alternating current, arc welding power supply using inverter technology is called inverter welder. The inverter process requires high-power electronic switching devices, and the inverter welding machine using IGBT as the switching device is called IGBT inverter welding machine.
Inverter welding and cutting equipment is composed of inverter power supply and external equipment. Inverter power supply is the main equipment of inverter welding and cutting equipment, and its working process is:
Power frequency AC - DC - High frequency AC - transformer - DC
The working process of inverter welding and cutting equipment is to rectify and filter the three-phase or single-phase 50Hz power frequency alternating current to obtain a smooth direct current, and the inverter circuit composed of IGBT or field effect tube will change the direct current into 15 ~ 100kHz alternating current. After the step-down of the medium frequency main transformer, Rectifying the filter again to obtain a smooth DC output welding current (or re-inverting the output of the desired frequency of AC).
The control circuit of inverter welding and cutting equipment consists of a given circuit and a drive circuit, etc. Through the feedback processing of voltage and current signals, the cycle control of the whole machine is realized. The pulse width modulation PWM is adopted as the core control technology, so as to obtain the constant current characteristics of fast pulse width modulation and excellent welding and cutting process effect. Its working principle is shown in the following figure:.
To understand the principle of IGBT inverter welding machine, only need to understand the principle of the welding machine and the principle of the IGBT chip on the line, look at the schematic diagram of the control board drive board is useless