A power harmonic measurement system based on wavelet packet transform and ARM9

A real-time harmonic measuement system is presented in the paper. The system is combined by the ARM9 chip and virtual instrument technology. the paper set out the system´s hardware structure diagram, harmonic analysis algorithm, the simulation result, and the LabVIEW subroutine which used to show the result. The wavelet packet transform is used to detect harmonics which can highly meet the requirements of the harmonics measurement. And data acquisition server get data from the the storage of the ARM system, and stored data to the database, remote monitoring computer can access the data through the Internet network. As a result, it proved that the system can improve the time-frequency resolution obviously and track the changes of all harmonics on real-time by using wavelet packet transform.