The use of high power converters has increased tremendously. Increased demand for
transportation, housing and industrial needs means that more number of power
converters interact with the utility power grid. These converters are non-linear and they
draw harmonic currents, significantly affecting power quality. To reduce harmonics,
filters, power factor correction circuits and capacitor banks are required. And the
development of hybrid technologies and renewable energy power stations trigger a
demand for power converters with bi-directional capabilities. The objective of this thesis
is to develop a high power quality, bi-directional AC-DC power converter that is a
solution to the aforementioned problems.
This thesis studies an existing topology for a high power AC-DC power conversion with
transformer isolation. The topology consists of an uncontrolled rectifier followed by a
DC-DC converter to produce a set voltage output. A design example of the topology is
simulated using the PSIM software package (version 6). Critical performance
characteristics such as power factor and total harmonic distortion are analyzed.
Following that study a new topology is proposed, which is an improvement over the
older design, with reduced power conversion stages. The new topology has a fully
controlled current source Pulse Width Modulation (PWM) rectifier at the front end to
replace the uncontrolled rectifier and DC-DC combination. This topology has multiquadrant
operational capabilities and the controller employs Selective Harmonic
Elimination techniques to produce the programmed PWM switching functions for the
rectifier. A design example of the converter and the digital controller are simulated in
PSIM environment. The converter input current THD (Total Harmonic Distortion) and
input power factor are within IEEE 519 and DoE standards. The converter is simulated
in both first and fourth quadrant operations.
A side-by-side comparison of the two topologies is done with respect to design and
performance features such as power factor, THD, filter size, etc. The new topology
converter provides performance superior to that of the older topology. Finally the thesis
explores possible applications for the converter in power supplies, renewable energy and
hybrid technologies.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-05-7743 |
| Date | 2010 May 1900 |
| Creators | Essakiappan, Somasundaram |
| Contributors | Enjeti, Prasad |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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