EMC solution for inverter welding machine

Abstract

The invention provides an EMC solution for an inverter welding machine. The EMC solution comprises an EMI filter rectifier circuit, an active power correction circuit, a flyback switching power circuit, a double-switch single-ended forward driving circuit and a switching power synchronization circuit, wherein the EMI filter rectifier circuit is used for filtering various interference signals entering the inverter welding machine through a power grid; the active power correction circuit is used for correcting current input into the welding machine, reducing harmonics caused by current distortion, and increasing the utilization rate of the welding machine over the electric energy of the power grid; the flyback switching power circuit is used for providing stable direct current voltage output; the double-switch single-ended forward driving circuit is used for performing power amplification on a PWM signal output by the flyback switching power circuit in the manner that the double-switch single-ended forward driving circuit can be driven by the PWM signal subjected to power amplification to work; the switching power synchronization circuit is used for filtering a negative signal output by the double-switch single-ended forward driving circuit, and stabilizing, amplifying and feeding the negative signal back to the flyback switching power circuit to synchronize the working frequency and the working frequency of a switching power supply.

Description

technical field [0001] The present invention relates to an inverter welding machine, in particular to an EMC solution for an inverter welding machine. Background technique [0002] Inverter welding machines have been widely used, and compared with thyristor rectifier welding machines, they have been greatly improved in terms of improving efficiency, reducing volume, and reducing quality. However, the AC / DC electrical efficiency of current inverter welding machines (especially single-phase 220V inverter welding machines) is actually very low. This is not due to the loss and heat of the inverter itself, but due to its The higher harmonic current reduces the power factor of the welding machine, and the higher harmonic current causes great pollution and damage to the power grid. With the increasing use and popularization of inverter welding machines and other similar inverter power sources (such as uninterruptible power supply UPS, communication switching power supply), the los...

AI Technical Summary

Problems solved by technology

[0003] To suppress the harmonics generated by the inverter welding machine, it can be solved by adding a power correction circuit in the inverter welding machine. The increase of active power correction will aggravate the conduction and radiation interference of the inverter welding machine. The general solution is to increase The pre-filter circuit of the large inverter welding machine will increase the size and cost of the inverter welding machine

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