On the study of the quality of electric energy of switch power supply

Based on the analysis of the high frequency power rectifier and inverter switch power supply theory, it can be learned that switching power supply is the effect of the main sources of power. By special harmonic tester in nc machine tools, it is found that the switching power supply of harmonic wave in content and electromagnetic interference is very serious. This paper attempts to use the theory of low impedance with current direction to design a generic three phase passive filter device, so as to reduce and the harm caused by the switch power of their own control system harmonic pollution. The unit is not only can restrain harmonics, but also can improve the system power factor. The experiment has proved that application of this method can achieve satisfactory results, and has used in the numerical control switch power supply system.