Harmonic Analysis and Mitigation of Electronic Devices Using Passive Filter
The objective of this present work is to investigate harmonic profiles of single and three phase non-linear loads and also performance of passive filter that has been designed. The analysis has been carried out using real time harmonic profile measurement equipment. The loads which have been meas...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2005
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/6084/1/FK_2005_65.pdf |
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| Summary: | The objective of this present work is to investigate harmonic profiles of single and three
phase non-linear loads and also performance of passive filter that has been designed. The
analysis has been carried out using real time harmonic profile measurement equipment.
The loads which have been measured are television, video compact disc (VCD) player,
sound system, desktop and laptop personal computer (PC) , motor, unintermpted power
supply (UPS) and office automation facilities. Passive filter vis-a-vis active filter is used
in the experiment because it is maintenance free and of its low cost and trouble free
operation. All single phase loads, which were measured, showed that total current
harmonic distortions (THDs) are above 100% because they have low fundamental
current. Furthermore, most of the harmonic current especially 3rd, 5 th ,7 th , and 9h
harmonic order currents were almost 90% of the fundamental current. For three phase system, different types of non-linear loads exhibited different types of profiles.
Comparatively, UPS current waveform was more distorted and its THD is higher than
motor current waveform. This is because the electronic devices such as UPS, TV, PC etc.
are using low current compared to other loads such as central air conditioning system
which are not controlled by electronic devices but use chiller for operation. For office
load automation facilities at multi storey building, new additional loads can cause the
system to become imbalance due to improper wiring connection at DB. Different types of
loads and modes of operations can also contribute to cancellation of total harmonic due to
phase angle diversity and attenuation of system impedance. In these studies, current
harrnonic is more relevant than voltage harmonic because the results show that most of
the THDs voltage readings are low compared with THDs current.
Results from passive filters showed that the installation of filters can reduce up between
40% - 50% of THD current, output current waveform is improved which is verified by
simulations and all currents harrnonic value is increased extensively. This shows that
installation of passive filter can resonate the circuit and prevents the harmonic current
from flowing.back to the power source which cause only minimum problems to the
voltage waveform |
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