Consider A Grid Background Harmonic Single-tuned Filter Computer Aided Design

The single harmonic filter is one of the widely used devices in the power system. It can decrease the voltage aberration caused by the abundant harmonic weight in the load current.In this paper, the actual filter effect was studied based on the analyzing of the cause and the harm of harmonics. The stress was the study of the new methods of calculation the harmonic voltage and the harmonic current, and a new concept of filter ratio to evaluate the actual effect of single harmonic filter was raised considering the background harmonics. As well, the calculation mode of the single harmonic filter was also given based on the concept of filter ratio; it can offer effect data to evaluate the actual filter ratio of the single harmonic filter. At the same time, a method of designing the single harmonic filter was given, too, considering the background harmonics of the power system. In this paper, both the computer analysis and the proven had been done. And the result was shown to be that the voltage aberration and the harmonic current were decreased, and that the actual filter ratio of single harmonic filter was raised. The reason that we must consider the background harmonics when designing a single harmonic filter was also expatiated in this paper.