Research On Welding Power Supply With Zero Current Soft-switching

IGBT is commonly used in the half-bridge inverter arc welding power supplyas the main power switch. The commutation loss of the inverter is mainly attributedto the tail current of IGBT. In order to reduce the IGBT turn-off loss, the designhere adopts the zero-current soft-switching (ZCS) technology to deal with it. In thethesis, the half-bridge inverter arc welding power supply is the object to bediscussed. The zero-current soft-switching technology is applied on the device toreduce the loss caused by the tail current of IGBT.Firstly, the operation principle of the half-bridge zero-current quasi-resonantpower topology is analyzed from a theoretical point of view. the asymmetricalPWM is adopted in the gate pulse timing to coordinate the operation of ZCS tankand series resonant tank, which determines the working process of the circuit.According to the analysis of the entire process, the meaning and method ofcalculation about some important parameters are illustrated in the relevant chapters.After theoretical analysis, parameter calculation and simulation in Saber softwareare done, acquiring a more complete set of simulation data to illustrate thefeasibility of zero-current switch.Secondly, According to the theoretical analysis, simulation results andpractical experimental conditions, the matching of the hardware circuit devices areanalyzed and discussed to obtain a building scheme. In order to improve thedynamic response and control accuracy, the design uses the Microchip’sdsPIC30F4011MCU as the controller. The programming of controller has also beendone in accordance with the requirements of operation principle.Lastly, after building hardware circuit, a0.4kW prototype of ZCS-PWMDC-DC power converter is analyzed using experiment. The measured resultsdemonstrate the feasibility of zero-current soft-switching technology in theapplication of arc welding power supply with a certain duty cycle range and loadrange.