Abstract
The authors investigated the control of welding current with a frequency-controlled inverter power supply. Welding current control requires precision sensing of the inverter current, which can reach 10kA. The current transformers and Hall effect devices commonly used in the industry do not deliver the desired performance. The authors investigated the use of a shunt-type current sensor based on the simplest RI drop method for current detection. This paper discusses the investigation of the extent to which sensor inductance can be cancelled out when using the shunt-type current sensor. Experimental results indicate that the inductance component can be cancelled out, thus making non-inductive operation possible. A current sensor has been prototyped and used in a frequency-controlled inverter power supply, demonstrating that welding current control is possible.
