The investigated on Harmonic Monitoring for the Inverter Applications by using Microprocessor

This research studied the quantities of harmonics cause from the inverter applications, which were used widely in the residential, and farm. Harmonics were considered as non-pure sine waveform that could be affected to the other near by electrical equipment such as additional heating and higher dielectric stress on the capacitors, interruption capability of circuit breakers, the skin effect of the conductors, measurement errors, pulsating torque and noise on rotating machines. Therefore, this paper proposed a process for the harmonic monitoring from the inverter by detecting the signal of current waveform and voltage waveform; The sensors and microprocessor is used to detect the harmonic components, then the Fast Fourier Transform (FFT) is calculated and estimated the harmonic of the spectrum of the order 3, 5, 7, and 9. As the results, the accuracy of measurement is normally related to the percent of Total Harmonic Distortion (THD) of the signal. Which can be concluded that, the average error of THDi is approximately 9.41% when compare to the reference digital meter UNI-T UA28T.