Research On Harmonic Suppression Technology For Electronic Equipment

With the development of power electronics, electronic equipments with rectifier circuits have been the main harmonic sources. Harmonic pollution brought by those equipments is more and more serious. This paper concerns on the study of harmonic suppression for electronic equipments.At first, this paper analyses the harmonic on AC side of rectifier circuits and obtains a uniform harmonic model. Harmonic source is classified according to the characteristics of the harmonic current caused by rectifier circuits. Then, it is obtained that electronic equipments with rectifier circuit can be equaled to rectifier circuit of which the load is resistance as studying its harmonic by analyzing switching power supply and frequency converter. It is proposed that the harmonic source type of electronic equipment can be ascertained based on the type of rectifier circuit if its circuit is known and based on the input current wave if unknown. Finally, the corresponding harmonic suppression method is represented for different harmonic sources. For the problem of harmonic voltage source, the paper develops a suppression method of using autotransformer and resonance of parallel connection. The sensitivity of harmonic filter using this method is discussed and the relationship between insert loss of harmonic filter and its parameter variety is deduced. Given a range of insert loss of the harmonic filter, a discussion about the range of its parameter is done. In addition, the performance of the filter is testified by simulation and experiments, and difference between simulation results and experiment results is analyzed.