150KW Solid State High Frequency Compact Pipe Welder

Because the thyristor rectifier adopts phase-shifting control, the power regulation is to adjust the voltage by changing the trigger angle. The circuit absorbs the sine wave with missing angle from the power grid, and leaves another part of the sine wave with missing angle to the power grid. Obviously, the left part contains a large number of harmonics. At the same time, the power factor is low due to different voltage and current phases (the lower the DC output voltage, The lower the power factor).

The theoretical calculation and test show that when the trigger angle of three-phase fully controlled bridge rectifier is zero, or when the uncontrollable bridge rectifier composed of diodes is used, the harmonic generated is very small and the power factor is very high (more than 0.9). However, in practical application, it must have the function of continuously adjusting DC voltage (that is, adjusting output power), and the equipment can not work at full voltage forever. In order to make the equipment have the minimum harmonic, the highest power factor and adjustable output power, another voltage regulating device must be added behind the uncontrollable rectifier bridge.

Therefore, after intensive research, we have developed the numerical control rectifier technology and obtained the national patent (zl201520767232. X).

The three-phase four wire 380V, 50Hz AC used in general industry is rectified by "three-phase rectifier bridge" (composed of six ZP diodes and one-time rectification) to become 300Hz pulsating DC, then transformed into smooth DC after LC filtering (composed of reactance and capacitance), and then transformed into AC with controllable frequency and voltage of more than ten kHz after inversion and voltage regulation by single-phase inverter bridge (composed of four groups of IGBTs), Then it becomes low-voltage pulsating DC after high-frequency transformer step-down and diode rectification (secondary rectification), and then becomes smooth low-voltage DC after reactance or capacitor smoothing and filtering.

The single-phase inverter bridge composed of IGBT has two functions: inverter and voltage regulation. In other words, the output voltage can be adjusted according to production needs while reversing DC to AC.

The high-frequency transformer adopts ferrite as magnetic conducting material, and the primary transformation ratio is designed according to needs, with small volume, low cost and high conduction efficiency.

The TENYES 150KW Solid State High Frequency Compact Pipe Welder with PWM numerical control rectification technology has the following advantages:

1)High power factor: power factor ≥ 0.92, no need to add reactive power compensation equipment.

2)Low harmonic pollution: generally, there is no need to add additional harmonic treatment equipment

3)Stable output power: output ripple ≤ 0.2%, and the burr of the welded pipe is more uniform.

4)Fast protection speed: fault interlocking protection time ≤ 10 μ S. The equipment is more reliable.

5)High power efficiency: because the reactive power loss is reduced, the efficiency of the whole machine is improved.