A Study On The Measures To Improve The EMC Of The Domestic Arc Welding Inverter

The key to study the Electromagnetic Compatibility (EMC) is to resolve theElectromagnetic Interference (EMI). Serious EMI not only reduces the performanceof the system itself, but also pollutes the environment. Many countries have paid greatattention to the EMC of equipment, and have made some strict standards in order toreduce the influence of the EMI on the environment. The electrical welding machine,one of 132 products in 19 groups, has been rigidly restricted on EMC by 3C(ChinaCompulsory Certification), which was put into effect on August 1, 2003. As far asEMC is concerned, foreign factories of welding machines have carries out specialresearch on the EMC of equipment. However, domestic manufacturers seldom put itinto consideration because of the limited conditions. Therefore, the EMC ofequipment is a problem that must be solved in order that domestic welding machinescan pass 3C certification.Taking ZX7-160 arc welding inverter for example, this paper inquires into themeasures to improve the EMC of the domestic arc welding inverter. It discloses thespectrum characters of the conducted interference signals in electrical weldingmachine with wavelet package. On that basis, the LC filter and the active power filter(APF) are designed for restricting conducted EMI. The simulation model of APF ismade with the help of the software MATLAB.In this paper, the results of simulation and experiment are presented to confirmthe effectiveness of the designed filter . This method can also reactive powerimmediately.This paper lays the foundation of furthering research on the EMC of other kindsof domestic arc welding inverters.