Harmonics Detecting System Of Adaptive Neural Network Based On LabVIEW

With the development of modern power electronics technology, the application of various power loading which are non-linear become more and more wide, which causes the harm of harmonics in electric systems is much more serious. The real time and accurate detecting of harmonics is significant to the supervision and prevention of contamination.Above all, the harmonics detecting method of adaptive linear neural network is studied in this paper after compared a few harmonics detecting methods in existence. The method has the virtue of rapid response, high precision and outstanding adaptive ability. It can detect general harmonics and specific harmonic. At the same time, the effect of studying factor to following speed and precision is discussed especially, adaptive harmonics detecting method based on variable studying factor is proposed and the other improving methods based on two layers neural network are summarized. Also simulation is made for those methods with MATLAB software.Following, after a brief introduction of virtual instrument and graphics language LabVIEW, the software and hardware is designed for the adaptive harmonics detecting system. The hardware is made up of Data Acquisition card (DAQ) and signal conditioning extension for instrumentation (SCXI) which is composed of Hall voltage current sensor. LabVIEW is selected for software. Because measure precision is effected by frequency change, software frequency tracing is adopted in the paper. The in-phase problem about the reference input and the fundamental wave of voltage when harmonics of current is detected is solved by software also. At the same time, the function is completed by software which involves the harmonics detecting based on adaptive linear neural network, data managing, test report, printout and so on. The methods of programming are explained in detail in the article.To prove the capability of the system, an experiment is conducted through acquiring and...