Abstract: Voltage sag, voltage swell, high-frequency noise and voltage transients are kinds of disturbances in power quality. They are also known as power quality events. Equipment used in the industry nowadays has become more sensitive to these events with the increasing complexity of equipment. This leads to the importance of distributing clean power quality to the consumer. To provide better service, the best analysis on power quality is very vital. Thus, this paper presents the events detection focusing on voltage sag and swell. The method is developed by applying time domain signal analysis using wavelet transform approach in MATLAB. Four types of mother wavelet namely Haar, Dmey, Daubechies, and Symlet are used to detect the events. This project analyzed real interrupted signal obtained from 22 kV transmission line in Skudai, Johor Bahru, Malaysia. The signals will be decomposed through the wavelet mothers. The best mother is the one that is capable to detect the time location of the event accurately.
Abstract: The significance of psychology in studying politics
is embedded in philosophical issues as well as behavioural
pursuits. For the former is often associated with Sigmund Freud
and his followers. The latter is inspired by the writings of Harold
Lasswell. Political psychology or psychopolitics has its own
impression on political thought ever since it deciphers the concept
of human nature and political propaganda. More importantly,
psychoanalysis views political thought as a textual content which
needs to explore the latent from the manifest content. In other
words, it reads the text symptomatically and interprets the hidden
truth. This paper explains the paradigm of dream interpretation
applied by Freud. The dream work is a process which has four
successive activities: condensation, displacement, representation
and secondary revision. The texts dealing with political though can
also be interpreted on these principles. Freud's method of dream
interpretation draws its source after the hermeneutic model of
philological research. It provides theoretical perspective and
technical rules for the interpretation of symbolic structures. The
task of interpretation remains a discovery of equivalence of
symbols and actions through perpetual analogies. Psychoanalysis
can help in studying political thought in two ways: to study the text
distortion, Freud's dream interpretation is used as a paradigm
exploring the latent text from its manifest text; and to apply Freud's
psychoanalytic concepts and theories ranging from individual mind
to civilization, religion, war and politics.
Abstract: This study examines the design and construction of AC Electronics load surge protection in order to carry electric surge load arisen from faults in low voltage electricity system (single phase/220V) by using the principle of electronics load clamping voltage during induction period so that electric voltage could go through to safe load and continue to work. The qualification of the designed device could prevent both transient over voltage and voltage swell. Both will work in cooperation, resulting in the ability to improve and modify the quality of electrical power in Thailand electricity distribution system more effective than the past and help increase the lifetime of electric appliances, electric devices, and electricity protection equipments.
Abstract: Chitosan is an attractive polysaccharide obtained by
deacetylation of an abundant natural biopolymer called chitin. Chitin
and chitosan are excellent materials. To improve the potential of
chitin and chitosan modification is needed. In the present study,
grafting of maleic acid on to chitosan by cerium ammonium nitrate in
acetic acid solution was investigated with use of a microwave and
reflux system. The grafted chitosan was characterized by using a
Fourier-transform infrared spectrometry. The solubility and swelling
behavior of grafted chitosans were determined in acetate buffer (pH
3.6), citrophosphate buffer (pH 5.6 and pH 7.0), and boric buffer (pH
9.2) solutions. The sample obtained by microwave system with use of
a chitosan/maleic anhydride/ceric ammonium nitrate 0.2/3.922/0.99
gram of raw material within 30 minute showed the maximum
swelling ratio (13.6) in boric buffer solution.
Abstract: Process control and energy conservation are the two
primary reasons for using an adjustable speed drive. However,
voltage sags are the most important power quality problems facing
many commercial and industrial customers. The development of
boost converters has raised much excitement and speculation
throughout the electric industry. Now utilities are looking to these
devices for performance improvement and reliability in a variety of
areas. Examples of these include sags, spikes, or transients in supply
voltage as well as unbalanced voltages, poor electrical system
grounding, and harmonics. In this paper, simulations results are
presented for the verification of the proposed boost converter
topology. Boost converter provides ride through capability during
sag and swell. Further, input currents are near sinusoidal. This
eliminates the need of braking resistor also.
Abstract: In the power quality analysis non-stationary nature
of voltage distortions require some precise and powerful analytical
techniques. The time-frequency representation (TFR) provides a
powerful method for identification of the non-stationary of the
signals. This paper investigates a comparative study on two
techniques for analysis and visualization of voltage distortions with
time-varying amplitudes. The techniques include the Discrete
Wavelet Transform (DWT), and the S-Transform. Several power
quality problems are analyzed using both the discrete wavelet
transform and S–transform, showing clearly the advantage of the S–
transform in detecting, localizing, and classifying the power quality
problems.