Analysis And Design Of The Main Circuit Of Inverter Resistance Welding

With the more degree of mechanization, automation and intelligence, resistance welding has become one of the main direction in welding field. In the past years, Inverter resistance welding power source with soft-switching technology has smaller volume, lower quality, higher efficiency.The basic topological structure of the main circuit of the inverter-based power supply such as forward converter, half-bridge circuit, full-bridge circuit is first introduced in this article, So as to propose three kinds of soft switching FB circuit topological structure, ZCS , ZVS , ZVZCS , those are suitable for medium-power or larger-power. The operation principle of FB-ZVZCS circuit for resistance welding has been explained in detail, and has carried on careful analysis to its micro dynamic course, solving the shortcomings of the routine inverter resistance welding power such as heavy stress of the amplifier tube while switching, dependability low and polluting the electric network etc. Introduced a newly designed inverter resistance welding power on this basis, main circuit's topological structure adopt FB-ZVZCS, and do some work about the parameters design and calculate; Select IGBT for power switch device, design one urge circuit for IGBT independently; UC3875 is been used for controlling core of the control system, realized shifting phase output by using the peripheral circuit we designed. Adopting the optocoupler TLP250 for isolation, make the output waveform of the control system noiseless. Meanwhile, this subject including the design of the circuit of control index setting, feedback close loop control circuit, current foldback circuit, overheat and low-voltage protection circuit, have really realized the functions of self-regulation, trouble diagnoses and display.Finally, give some introduce about the debugging and installing of the main circuit board and control circuit board. The result of the test shows: The FB-ZVZCS circuit the subject developed work steady, realizing the advanced arm zero voltage switching, the delayed arm zero current switching, the output waveform of the control system is normal, and the phaseshifting angle can regulate succession. The subject have reached the anticipated designing requirement.