The Research On The Detection Of Inter-harmonic Based On Windows Spectrum Estimation

With the widely application of all kinds of power electronic instruments, the influence of harmonics in power system becomes more and more serious, and inter-harmonic's frequencies are not an integer of the fundamental, and the effects of them cause an increasing interest among electrical power engineers.Studying on inter-harmonics is an ulterior development for harmonics problem and external requirement of knowing deep steady-state power quality of power system, so it is important to analyze inter-harmonics accurately. Considering the characteristic of inter-harmonics, this paper present and analyze same detecting methods based on different models, introduce the available scope and of each method, and compares these methods on their advantages and shortages.Spectrum estimation is widely used in detecting of stochastic signal, which can describe frequency characteristic by using of statistics. This paper presents windows spectrum estimation based on spectrum estimation deeply studied and confirmed the position where window function would be placed, and analyzed performances of kinds of windows with their application scenes, then concluded effects on impaction correlation function and spectrum estimation with windows in the abstract. According to Simulation, it can differentiate inter-harmonic signals with some windows, such as Hanning, Blackman and so on, which improves the conventional spectrum estimation.Finally, in allusion to no periodic sampling, the system validates performances of kinds of window functions, and validates the performance of Hanning window function by experimenting,which can be used as part of system of power quality detection on platform of LabVIEW.