Solid State H.F. Welder For MS Pipes

Functional structure

The solid state high frequency equipment mainly used for HF welded steel pipe line, it is a typical AC-DC-AC variable frequency structure. Rectifier adopts 3-phase bridge style thyristor phase-control rectifier circuit, DC side adopts inductor, capacitor to compose LC filter which meet the working requirements of voltage type inverter. The voltage type inverter adopts modularization parallel structure to extend power supply power, each inverter module is single phase MOSFET bridge style circuit connected with series resonance tank circuit by H.F. matching transformer. On one hand, the matching transformer realizes power combination and impedance matching; on the other hand it realizes electric isolation of load and power supply. To put effective and swift protection on over-current malfunction of voltage type inverter, our company introduces special and stable over-current protection circuit which guarantees safe and stable running of inverter.

The whole set of solid state H.F. welder comprises of switchgear rectifying cabinet, inverter output cabinet, connecting optical fiber, circulation soft water cooling system, central operator console, mechanical adjustment device, contact welding pole plate and contact pin (contact welding) and etc

Technical Feature

1.1 The solid state H.F. welder adopts Germany IXYS company IXFN38N100Q2 38A/1000V high-power MOSFET and DSEI 2×61-12B 60A/1200V rapid recovery diode to compose series type invertible circuit.

1.2 The solid state H.F. welder adopts modularization design with more compact structure which makes maintenance and high-power realization much easier.

1.3 It has particular technology of bridge-divided over-current protection that guarantees equipment safety.

1.4 It combines international advanced control method of same products, adopts advanced technologies like fixed angle phase-locking control, upper frequency limit/lower frequency limit lock-lost protection and etc. With these technologies, the equipments run more stably, more efficiently, more accurate and effective protections to the inductor short-circuit and open-circuit malfunction during pipe welding production.

1.5 Speed-power closed-loop control system which is an optional installation to user, it highly improves welding efficiency and reduces technics adjustment period.

1.6 Line-in end of solid state H.F. welder does not need step-up /step-down rectifier transformer, compared with vacuum tube welder and parallel type welder; it has significant energy-saving effects (Under same welding condition, energy-saving ≥30% compared with vacuum tube welder).

1.7 The solid state H.F. welder designed with the most advanced electric-load-matching technology (PS+PWM control) which keeps solid state H.F. welder on a high welding efficiency, high power coefficient (>0.9), optimizing load matching status and can be switched under induction welding/contact welding double function mode.