Research On Three Phase Power Phase Measurement System Based On APFFT

For the measurement of the three-phase power, voltage and current is the important measurement object in the power detection system and control system. How to measure fast and accurately phase value has become an important research topic in the field of production and scientific research. The accurate measurement of phase difference has an important value for the study apparent power, active power and power factor etc, but is not easy to be completed.At present, phase measurement method of power frequency three-phase power signal containing multiple harmonic, is generally based on the Hanning window FFT correction measurement methods. But their accuracy limited by the conventional FFT features is very difficult to guarantee. When the measured instantaneous phase is very small, the phase difference accuracy measured will be reduced; when the measured signal contains a large number of harmonic components, a larger measurement error will be made; when the cycle of the detected signal is instable, non-synchronous sampling will be produced so that the measurement accuracy will be affected. To solve the problems above, the subject puts forward all phase FFT phase measurement algorithm. The algorithm makes the measurement of small phase difference still maintain high accuracy and makes the measurement results not affected by the harmonic component and non-synchronous sampling. The paper compares the characteristics between all phase FFT algorithm and the conventional FFT algorithm from the theoretical formula; using Matlab simulation of three-phase electrical signal verify superior characteristics of all phase FFT from the qualitative and quantitative; the phase measurement algorithm verification system designed by LabVIEW platform measure the actual three phase power signal to verify the validity of the phase measurement algorithm; to DE2board as the hardware platform the phase measurement system of three phase power is completed, the underlying software of the system modular design using SOPC technology, and the upper software transplant UCGUI system to design interface system; finally, using the dual-channel signal generator, it is verified real-time and effectiveness of the portable system.