Develop Of Parameter Tester In Power System Based On FFT

With the extensive application of power electronics technology, non-linearloads increase the power system harmonics pollution, which has a great effect on thesafety and wheeling of the power line, the accuracy of electrical energy metering, thewheeling of electrical equipment. Therefore, it is very necessary to detect the powersystem harmonics and other parameters in real-time.After a review of literature combined with the existing harmonic measurementmethods, it designs the power system parameter tester based on digital frequencydoubling technique and FFT algorithm. This method can not only speed up the datacalculate rate, but also reduces the volume of the instrument.After the signal of power system through the transformers, filtering and shapingit obtain the fundamental frequency of power system. The256multiply frequencywhich produced by method of digital frequency multiplier is switched in interrupt pinact as the ADC sampling trigger pulse. It achieves full cycle of signal sampling andeffectively avoids the FFT algorithm and a fence effect spectral leakage, Increase theaccuracy of the analysis results. With the FFT analysis and data treatment, it gets thevoltage, current, power, power factor, frequency and other parameters.and displaythe corresponding parameters on the LCD scereen. Tester establishs communicationwith the PC by USB, according to PC communication command, transmits thecorresponding data to PC. After PC gets data, it shows the basic parameters anddraws waveform plots. At last it achieves power system parameters both short-rangeand remote monitoring.The tester can more accurately measure the harmonic content in the powersystem and it is able to get the corresponding voltage, current, power, power factorand other parameters, to better monitor the operation of the power system, to provideusers with convenience.