The whole set of high frequency solid state welder is composed of switch rectifying cabinet, inverter output cabinet, central control console,mechanical adjusting equipment, water cooling system and an air conditioner.
A. Switch Rectifying Cabinet
1) We integrate the switch gear cabinet part and rectifier part, besides the functions of switch cabinet, this design also has rectifying control functions on solid-state H.F. welders.
2) Install incoming disconnect switch ,incoming current meter, voltage meter(switchable)and incoming voltage indicating light.
3) Install 3-phase full-controllable thyristor rectifying bridge to achieve power regulation of H.F. welders.
4) Install flight wave reactor, flight capacitor and filter to increase flight coefficient.
B. Inverter output cabinet
1) The invert part is considered of MOSFET single phase invert bridge in parallel style. Each bridge’s design power is 120 KW/60KW. We adopt building block mode to pile up power, it is very convenient to install and maintain because every single bridge board is designed as drawer structure consisted of slideway.
2) We adopt matching transformer to realize power combination, also we adopt sub-resonance, no-welding transformer output mode and make resonance directly by tank resonance capacitor(low voltage)and inductor to achieve steel pipe welding power transmission by output lead.
3) Use sealed box and install overhead air conditioning.
C. Central console
The console achieves remote control and power regulation of solid-state H.F. welder, installed with LCD; also it has indicators of armature voltage, field voltage on DC speed regulation cabinet and indicators of DC voltage, DC current on welder. Installation of power-speed closed loop control function is optional. The console has design difference according to different types and quantities of matching DC speed regulation cabinet.
D. Mechanical adjusting equipment
1) 2-D adjustable bracket: for induction welding mode, applied with installation and adjustment of invert output cabinet, the inductor position can be adjusted manually.
2) 3-D adjustable bracket: for induction/contract welding mode, applied with installation and adjustment of inverter output cabinet, the inductor position can be adjusted by electric or manual.
E. Circulation soft water cooling system (water-water cooler)
The water -water cooling system is composed of heat exchanger with the adoption of the special corrugated structure which makes the soft water form sharp turbulent flow in order to strengthen heat exchange. The system holds the advantage of compact design, small area occupation, convenient dismounting and high efficiency of heat exchange. Only with the ability of heat exchange but not cooling, it is necessary to use external circulation system to accomplish the heat exchange.
2. Maindesign indext of solid-state H.F. welder
1. Using high-power MOSFET, the equipment efficiency≥85%.
2. Using dual-loop PI regulator of voltage and current, the power range is adjusted from 0-100%.
3. Using the computer to control the voltage regulation, the adjustment is stable with high precision and small harmonic wave interference.
4. It has fault protection system with over-voltage, over-current and lack phase