Research On The Method Of Inter-harmonics Detection Based On Zoom Fast Fourier Transform

Harmonics in power system is usually defined as a component whose frequency is an integral multiple of fundamental wave (power frequency),The current national standard "Power Quality Harmonics of Public Power Grid GB/T 14549-1993" just stipulates limits and the methods of measurement for such harmonics,however, there are not relevant regulations for inter-harmonics,In fact, inter-harmonics and its influence exist widely in power system.Therefore, the problem of inter-harmonic in power system has received extensive attention. In order to analyze the influence of inter-harmonic on power system better, this paper proposes to use the analytical algorithm of complex modulation refined spectrum to realize local high-resolution spectrum analysis as a new method of detecting inter-harmonic.