1200kW rectangular iron steel pipe solid state HF welding machine

1. Application of 1200kW steel tube/pipe welding machine

Pipe specification: 355~630mm

Pipe specification: 15~25’’

Pipe thickness: 10~20mm

Pipe type: Round /square /rectangular

Welding mode: Induction/contact welding

Welding speed: 8~25m/min

2.Main Technical Index of 1200kW Solid State H.F. Welder

2.1 Designed parameters

Nominal power:1300kW

Rated DC power: P_d=1440kW

Rated DC voltage: U_dN=450V

Rated DC current: I_dN=3200A

The whole efficiency: η>85%

Output power: P_out>1200kW

Designed frequency: f=150~250kHz

MOSFET inverter: 120kW×12

circuit output mode: no welding transformer output, secondary resonance

2.2 Power distribution requirements

Nominal power:1200kW

Rated DC power: Pd=1440kW

Line-in power factor: COSφ0.9

Power distribution capacity: S<1600kVA

Power supply voltage: 3-phase 380V/50Hz

Line-in current: I=2610A

Line-in cable: each phase adopts four pcs of 300 copper cable, 3-phase 4-line

3. Composition of 1200kW steel tube/pipe welding machine

4. Brief introduction for steel tube/pipe welding machine

4.1Switchgear rectifying cabinet

Designed with integration of switchgear cabinet and rectifying part, besides achieving switchgear cabinet functions, it also has rectifying control functions of solid state H.F. welders.

l Installed line-in switch, line-in current meter, voltage meter (can be switched) and line-in voltage indication lamp;

l Installed 3-phase full-controlled thyristor rectification bridge to realize power adjustment of the HF welder;

l Installed flat-wave reactor, flat-wave capacitor and filter to improve the flat-wave coefficient.

4.2Inverter output cabinet

l The inverter part is consisted of MOSFET single-phase inverter bridge connected in parallel. The power of single-phase bridge is 120kW; the inverter bridge adopts the building block method to realize power superposition. Every piece of bridge plates is designed in the shape of a drawer, which is very easy to install and repair;

l The matching transformer is adopted for power combination, also it adopts the output method by of secondary resonance and non-welding transformer, tank circuit resonance capacitor (low voltage) resonates with the inductor directly, and the output pole plate offers required power transmission for pipe welding;

l Adopted sealed equipment case, installed with air conditioner.

4.3Connecting optical fiber

The switchgear rectifying cabinet and the inverter output cabinet are connected with optical fiber, so as to make sure control system can not be disturbed by HF signal, which enhances the reliability of equipment.

4.4Circulation soft water cooling system

Circulation soft water is used as cooling water with temperature and water level indicator and protection, which can perfectly accomplish the cooling work for rectifying cabinet, inverter cabinet and resonance tank circuit. air/water cooling system are optional.

4.5Central operation console

It realizes solid state H.F. welder remote operation and power regulation, installed with LCD which indicates armature voltage, field voltage indication and of DC drive and DC voltage, DC current indication of H.F. welders.

4.6Mechanical adjustment device

Applied to install inverter output cabinet and adjust inductor position.

2-D is for induction welding mode;

3-D is for contact welding mode.