Design and development of improved power quality based micro-butt welding power supply

This study proposes a suitable DC–DC converter topology with improved power quality at the input side for micro-butt welding machine by evaluating different power factor correction (PFC) techniques and DC–DC converter topologies. Firstly, different control strategies of boost converters such as peak current controlled PFC, average current controlled PFC and hysteresis current controlled PFC are discussed for minimising input current distortions and improving the power quality. Also, the current loop gain stability analyses are presented using small-signal model for selecting the best model and optimisation of the same. Secondly, the important key parameters such as cost, size, weight, complexity in implementation and other application dependent parameters of various isolated type of DC–DC converter topologies are compared and the best DC–DC converter topology is selected for the proposed application. Finally, the modelling and stability analysis is performed on the DC–DC converter and optimisation is achieved for the welding current controller. The software packages MATLAB/Plecs/OrCAD PSpice are used for simulation and implementation of the desired circuitry with optimised design. A prototype has been developed based on optimised design, hysteresis current controller for PFC and DC–DC converter; and the control algorithm is implemented DSP TMS320F2812 and the experimental results were discussed.