Study On The Equipment Of Checking & Measuring Harmonics In Single Phase Power System

The problems on power system harmonics have been attached widespread importance all over the world from one decade to the next. Electrified railway which has developed rapidly, the equipments of power electronics & power drive which have been applied largely in the departments of Chemical industry, Metallurgical industry, Coal industry ..., make the problems on power system harmonics serious day by day. Therefore, to control harmonics , to inspect and to harness harmonics have been set to an important position.At harmonics detection angle, the paper studied on the technology of checking & measuring harmonics in single phase power system, and mainly based on analyzing the technology of harmonics detection, The harmonics detection device has been designed to such a hardware system which has included a kernel TMS320F206 & AD73360, and the hardware system can detect the frequency of fundamental wave, and can accomplish sampling data, this system can carry through the method of digital signal process, and this system included serial ports which communicate between the hardware system board and Upper PC. In the software arithmetic on the system was included SPLL-Software Phase Locked Loop which can control the synchronous sampling of A/D, and then advance the precision of the every harmonics frequency scope and phase measured by FFT.the paper studied on the methods which have been applied to detecting Stable state Harmonics & Astable Signals in single phase power system.For Stable Harmonics detection, based on the method of checking and measuring in time filed.The technology of FIR-Finite Impulse Response with window data filter and 256 count out DIT-Decimation in Time Raxid-on-2-FFT (Fast Fourier Transform arithmetic), which can fulfill detecting the voltage and current harmonics signals which can detect 50th harmonics. The result of experiment validates the 89 stages FIR with Hann window can meet this design request.