PERANCANGAN MODUL GENERATOR HARMONISA ARUS LISTRIK DAN ANALISA HARMONISA ARUS YANG DIBANGKITKAN

Abstract

Harmonics is a problem in electric power quality, which can interfere with system performance. It requires a good simulation and modeling using the software and hardware to learn the phenomenon of harmonics. Simulation and modeling of harmonics using the software is commonly practiced. However, harmonic simulation using hardware not yet available in the Laboratory of Energy Conversion and Power Systems at the Electrical Engineering Department of Diponegoro University. To resolve the issue, in this thesis the author designed and built an electrical current harmonics generator module. Harmonics generator module is a loads circuit with a controlled switching system. The switching is performed using MOSFETs, by dividing one period of fundamental wave into 32 triggering angles. To keep the ratio between the frequency of the trigger signal and the fundamental wave remains constant, the PLL control system is used. Generated current wave form and harmonics can be set by arranging the number of loads for each triggering angle. The current harmonics generator module that has been made working on 220 volts AC 50 Hz, with 6 controlled loads and a linear load. It is able to generate even and odd order of harmonics current. The frequency of the generated harmonic currents is an integer multiple of the fundamental frequency, for example on third order harmonics current generation, the frequency of the fundamental current is 50.3Hz and the harmonic current is 150.8Hz. The higher harmonics order the less it's accuracy, and the other order of harmonic currents appear significantly. For example, on sixth order harmonics generation, the third order harmonic current appears up-to 13.1% and the fifth order harmonic current appears up-to 9.7%. On seventh order harmonics current generation, the third order harmonic current appears up-to 17.9% and the fifth order harmonic current appears up-to 15.5%. This is caused by the limities amount of load units and triggering angles. Installation of shunt passive filters on the module can reduce the harmonics on the order of that filtered, as on the third harmonic testing which can be reduced from 0.71A to 0.35A. But the value of other harmonic orders and the load current is increased. Keywords: harmonics generator, electric current, simulation, PLL.