Preface - kmutt

106
Cholburi, Thailand, p. 642
Power loss estimation in distribution
system scheme using meter measurement known
as technical loss technique is investigated. The
Principle of the system is to collect and analyze
customer kilowatt-hours in the main feeder and
sub-feeders. This loss data will be used as a
reference to compare to the losses estimated by
empirical equivalent hour loss of different
values of parameters. The parameters used were
determined from RMR meter readings and
commonly use values. Comparisons were done
and the result showed that the obtained values of
the parameters gave a more accurate estimate of
the total loss. Although, the experiment was
done for the PEA central area 1, the method can
be applied to similar power distribution systems.
IC-088 MEASUREMENT OF ALUMINUM
THIN FILM THICKNESS BY FIZEAU
INTERFEROMETER TECHNIQUE
Jittima Kongsakul, Nirun Witit-anun,
Surasing Chaiyakun, Pakorn Kaewtrakulpong
The 2005 Electrical Engineering/Electronics,
Computer, Telecommunications, and
Information Technology International
Conference (ECTI-CON 2005), May 12-13,
2005, Asia Pattaya Beach Hotel, Pattaya,
Cholburi, Thailand, p. 450
Thickness measurement of thin film
coated on a substrate is very important since
properties of the film depend largely on its
thickness. Several methods are available for the
measurement; however, most of them require
destruction or modification to the measurement
surface. In addition, some nondestructive
methods such as X-ray fluorescence technique
are complicated and expensive. Therefore, the
main objective of this work is to study a less
expensive nondestructive technique for thin film
thickness measurement using an optical
technique called Fizeau interferometer. In this
method, thickness of thin film is determined as a
difference of measured position of interference
fringe patterns. An experiment was setup to
examine its performance by comparing with a
stylus profiler technique. Results showed that
the approach could be used to measure
Aluminum thin film of thickness between 0.11-
0.39 µm with a comparable accuracy to the
stylus profiler.
KMUTT Annual Research Abstracts 2005
IC-089 ANALYSIS AND SIMULATION OF AC
TO DC SEPIC PFC BASED ON ZERO-
VOLTAGE-TRANSITION PWN TECHNIQUE
Preecha Mahamai, Ake Chaisawadi,
Veerapol Monyakul
The 2005 Electrical Engineering/Electronics,
Computer, Telecommunications, and
Information Technology International
Conference (ECTI-CON 2005), May 12-13,
2005, Asia Pattaya Beach Hotel, Pattaya,
Cholburi, Thailand, pp. 491-493
A Zero-Voltage-transition (ZVT) PWM
Sepic Power Factor Corrector (PFC) is proposed
to achieve unity power factor ≈ 0.99 under Zero-
Voltage-Switching (ZVS) operations. In the
proposed ZVT PWM Sepic PFC, not only the
main switch but also the main diode commutate
under ZVS. It aims to minimize the voltage and
current stresses. The proposed ZVT topology
has short ZVT time and minimum duty cycle
well qualified for variable duty and high
switching frequency applications. Moreover the
ZVT topology improves the drawbacks of
resonant switch PWM technique. Analyses on
the proposed are presented in details. A
prototype 120W, 50 KHz Pspice simulation is
used to verify the analysis.
IC-090 SINGLE SWITCH DUAL-OUTPUT DC-
DC POWER SUPPLY WITH FORWARD-
FLYBACK CONVERTERS
Kotchapong Sumanonta,
Yuttasak Rungruengphalanggul,
Ake Chaisawadi
The 2005 Electrical Engineering/Electronics,
Computer, Telecommunications, and
Information Technology International
Conference (ECTI-CON 2005), May 12-13,
2005, Asia Pattaya Beach Hotel, Pattaya,
Cholburi, Thailand, p. 181
In this paper the basic application of
converter for dual-outputs power supply
desigened on a forward-flyback converter is
introduced. The prototype power supply in this
paper combined a forward and a flyback
converter and uses a single switch for the 2
output voltages transfered from two parallel
transformers. The characteristic of this system is
different from a Multiple Output dc-dc
converters[4] that the spread of load is wider to
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