IGBT Inverter vs SCR Rectifier Welder: The Difference Explained

For a long time, traditional controllable silicon welders dominated the welding market and were widely accepted by most consumers. With the country’s requirements for energy saving and emission reduction, energy-saving inverters have entered the stage of welding.

Inverter welders are currently mainly divided into two categories: MOS tube inverter welders and IGBT inverter welders. Among them, IGBT inverter welders are the dominant ones. Let me explain the main differences between IGBT inverter welders and controllable silicon welders:

First of all, IGBT inverter welders are a new type of high-performance, efficient, and material-saving welding power source, representing the development direction of welding power sources today. Due to the commercialization of IGBT high-capacity modules, this power source has even broader application prospects.

Differences between the inverter welder and the controllable silicon rectifier welder

The differences between the inverter welder and the controllable silicon rectifier welder are as follows:

• The controllable silicon rectifier welder rectifies 50Hz AC power into DC power and changes the output size by altering the conduction angle of the silicon controlled rectifier. The output waveform is not smooth, resulting in poor welding performance and inferior arc ignition and control functions.
• Most IGBT inverter welders use AC-DC-AC-DC conversion to power the welding process. The 50Hz AC power is rectified into DC power through a full bridge rectifier, then inverted by the IGBT into a 20-30kHz intermediate frequency rectangular wave, which is reduced in voltage by the intermediate frequency transformer, rectified again, and then stabilized into DC power. The output waveform is smooth, and the output size is changed by controlling the IGBT inverter’s conduction time through PWM pulse width modulation or phase shift control. The arc ignition and welding current are easy to control.
• The controllable silicon rectifier welder is large and cumbersome, making it inconvenient to move, while the IGBT inverter welder has a small transformer due to the high inversion frequency of 20-30kHz, making it lightweight and easy to move.
• Inverter welders are about 30% more power-efficient than controllable silicon rectifier welders.
• The IGBT inverter welder’s control and main circuits are relatively simple, so its reliability is high, with few failure points and easy maintenance.
• IGBT control technology is already very mature and is the mainstream device for the new generation of inverters. However, due to the harsh working conditions of the welding power source, which frequently experiences short-circuits, arc ignition, and open circuit changes, the working reliability of IGBT inverter rectifier welding power sources has become the most critical and concerning issue for users.