Search

Rapid development in electrical technology has imposed strong challenges to modern power system. Power quality has become a great concern due to proliferation of power electronic technology in modern electrical loads. Specifically for lighting load such as compact fluorescent lamps (CFLs), one of the concerning issues is harmonics. CFL is a cost-competitive and energy efficient compared to incandescent lamp. Inevitably, CFL produces harmonics current due to nonlinearity behaviour of the electronic ballast circuit. This paper presents a study on the widespread installation of CFL lamps in electrical power network. Initially, the harmonic current characteristics of local-branded CFL was identified from laboratory measurement. Then, a simulated CFL model was developed in MATLAB/Simulink to replicate the identified characteristics. The same step was repeated for other two different brands where eventually all models were embedded into a distribution network. The results show that at low voltage level, with installation more than 50 units for each type of CFL, the harmonic voltage distortion exceeded the 8% total harmonic distortion (THD) limit as stipulated in EN50160 standard. However, at higher voltage, the amount of THD decreased to average 0.94% and further down to average 0.28% at small transmission voltage level.

This paper presents the performance investigation of voltage and current for dynamic model of the wind turbine. In this study, the various numbers of wind turbine speed are applied in the simulation. This treatment is intended to see how much influence the turbine speed has on the voltage and current output. IEEE 14 bus system is integrated to the wind turbine in order to observe the impact of on-grid connection to the voltage and current performance. How to model wind turbine in PSCAD simulation software also discussed in this paper. The detail of supporting components in designing a wind turbine system and their functions are also explained. Several values of turbine speed are also considered in this paper as a study material in seeing the performance of wind turbines. The relationship between wind speed and pitch angle will also be discussed to ensure that the wind turbine is not damaged. In order to prove the accuracy of the simulation model, the obtained measurement generation of active power from the wind turbine is matched with the manual calculation. Based on the various wind speed values that have been tested, this can be the basis for the application of wind turbine (renewable energy) design development for further research.

Achieving equivalence is a significant issue in translation work. However, since one language is different in many aspects from other languages, non-equivalence is inevitable in the process of translation. Non-equivalence arises when the target language cannot provide equal meaning to the source-language text. By applying the framework proposed by Baker (2011), this research was designed using descriptive qualitative method to find out the cases of non-equivalence at word level in the translation of Negeri 5 Menara. The results showed 55 cases of non-equivalence at the word level were found. The cases were classified into seven out of eleven categories; (1) culture-specific concept with eight cases, (2) non-lexicalized source language concept with three cases, (3) different distinction in meaning with nine cases, (4) target language lacks superordinate with one case, (5) target language lacks hyponym with 15 cases, (6) differences in expressive meaning with eight cases, and (7) the use of loan word in the source text with 11 cases. Additionally, the findings also exposed 21 cases that were not categorized into Baker’s (2011) types of non-equivalences at the word level. It was suggested that future researches discuss the topic of non-equivalence words by applying other translation theories aside from Baker’s in order to cover the issue of uncategorized cases found in this study. It is important for translators to understand the contribution of equivalency in both source and target language so that the potential of misinterpretation was avoidable.

Renewable energy known as green energy production had been rapidly developed to replace fossil fuel generators. Solar energy is one of the most utilized renewable energy because it can be obtained almost everywhere on earth. Solar energy is an unlimited energy source and it can be harvest in the safest way compared to other renewable energy source. Since the development of the photovoltaic system requires a lot of investment, preliminary testing had been carried out to uncover the solar energy potential based on the specific locations including the development of a solar energy potential measuring system. This paper presents the development of self-operating solar energy potential measuring system by using an ATmega 328P microcontroller-based setup. The system not only can measure the solar energy potential but using solar energy generates with its solar panel to operates the whole system. Based on the results, the system developed had successfully operated and measures the solar energy value at three different locations under different weather conditions.

In this paper, the performance of dye-sensitized solar cells (DSSCs) was analyzed using SCAPS-1D simulation. This research focuses on the thickness variation of semiconductor layers between 1 to 50k nm. The complete DSSC structure consists of ITO / TiO 2 / N719 / REDOX / Pt was used in this works. Four factors influencing the charge transfer between the DSSC layer are semiconductor thickness, operating temperature, doping concentration as well as the effect of neutral, acceptor, and donor defect were also analyzed. Next, the Voc, Jsc, FF, and PCE parameters were examined in each case based on the four factors mentioned above. The simulation results showed that the four factors analyzed are highly influential in improving the efficiency of DSSC. Based on this works, an efficiency of up to 8.14% can be achieved by applying a 50 nm ultra-thin layer of TiO 2 with a doping concentration of 1 × 1018 cm−3.

Solar irradiance is the most fundamental element for energy generation from the photovoltaic system. Huge number of measurement instruments are produced commercially for better reading of this parameter. Nevertheless, there are still no detail studies that have ever been reported regarding the critical relationship between solar irradiance and other electrical parameters such as voltage or current in the literature. This study is essential to determine the correct parameters to be considered in developing a precise measurement of solar irradiance. In this study, a linear-correlation based solar irradiance measurement device has been designed to investigate this relationship. The obtained solar irradiance values from the proposed device exhibit an excellent agreement with those measured by the commercial solar meters/sensors which highly suggest that this study should become a trigger for better improvement of the solar measurement system in the future.

The radiant energy from the sun is defined as solar radiation. It had been discovered as a renewable energy which can provide electricity supplies using a photovoltaic system. Before developing the system, a preliminary test must be carried out to perform the analysis of solar energy potential in that specific area. This preliminary test is known as a modeling technique. The technique will use the related parameters as an input to predict the solar radiation value. Since there are multiple parameters used for solar radiation prediction model development, there had been multiple attempts on using only certain parameters to produce predictions for solar radiation value. This paper will review and further analyzed several works presented by the previous studies on developing solar radiation prediction models using various parameters with their results. With the findings, the implementation of the Neural Network Autoregressive Model with Exogenous Input (NNARX) on solar radiation prediction carried out for the different input parameter configurations. Based on the results, it shows that the solar radiation prediction model development using more input parameters produced the best prediction performance with the R2 value of 0.9329.

Standalone photovoltaic (PV) system is practical and beneficial for the place where the physical power transmission line is not feasible. Nevertheless, for miniature scale standalone PV system, efficient and interactive energy management is extremely necessary to ensure that the battery is capable of supplying energy to the load uninterruptedly without any failure as its condition is being monitored, time by time. In this paper, a real-time energy management system equipped with wireless monitoring features has been developed and tested. All energy information such as battery voltage, generating current, discharging current, etc. are well displayed and extracted directly from the developed system. The high-power switching system is able to be controlled remotely as several MOSFETs attached to the main circuit are feasible to be flagged on or off via Blynk application instantaneously without any time lag. Therefore, the proposed system may become a good model for better small-storage-capacity based real-time energy management system in the future.

The new market trend shows CFL and LED lamps are rapidly replacing the conventional incandescent lamps. However, this resulted in power quality issues that strictly cause the problems to the power network with high injection of harmonics from these non-linear loads. The issue cannot be overlooked, especially when dealing with large lighting installation together with other non-linear loads. This paper examines the harmonic emission from both CFLs and LEDs in distribution network by running a laboratory test with various type of brands from the local market. The total harmonic distortion is analyzed and measured under three different perspectives; first, using 12 LED units of the same brand in different power ratings; second, using 12 LED units of different brands in different power ratings; and lastly, a mix of 8 units LED and 4 units CFL with different power ratings are tested. The last case reveals significant reduction in level of total harmonic distortion.

The aim of this paper is to develop an analyzer for detecting and evaluating hotspot in problem in a photovoltaic (PV) module. There are many causes that can lead to the hotspot in PV modules such as shading effect, impurities present on the module surface and many more. The proposed system will capture the thermal images of the PV module and analyze each region in the image. The system will detect the hotspot regions and evaluate the severity level of the hotspots. Though the experiment, the proposed system could produce a reliable result compared to the conventional approach.

Underwater communication has a great importance in either industrial, military or for scientific purposes. The applications of underwater communication such as pollution monitoring, underwater surveillance and collection of scientific data from the bottom of the ocean require specific development of devices. In order to design these crucial devices for such activities, an accurate characteristic of water involved should be noted. The velocity of signal propagates in underwater is different from the speed of light in free space and closely related to complex permittivity. There are few types of water bodies such as rivers, streams, pond, bays, gulfs and seas where each of them possessed different characteristics. In this paper, the main focus is to determine the water bodies’ characteristics by using material characterization method. This paper provides the characterization of the different water bodies such as tap water, river water, sea water and lake water where the complex permittivity are determined by using resonant method. Estimated complex permittivity of different water are in good agreement with existing method; the error is below than 6%. The present method shows a great potential to be used in characterizing wide-variety of liquid samples.

An ultra-wideband antenna design is proposed in this paper based on simple and easy-fabricated rectangular patch antenna. The proposed antenna is inserted with two slots; inverted U- and C-shaped to minimize interference in WiMax and WLAN band. The antenna can afford a good range of operating frequency from 2.852 to 12.176 GHz, which covers ultra-wideband frequency range set by Federal Communication Commission and in the same time be able to avoid undesired band.

Stand-alone system is the system that operates independently of the electrical grid. Conventionally, the energies absorbed through photovoltaic modules are stored in batteries to reserve for night-time use. Moreover, the function of batteries in stand-alone system is to stabilize the output supplied for the load particularly during the fluctuating circumstance. Sudden shutdown of dedicated photovoltaic system during this period may occur when the storage of batteries approaches empty level which may significantly degrade the lifespan and performance of the batteries. In this study, a sequential load switching system is introduced in order to over-come the sudden shutdown of storage battery-based photovoltaic system. The developed system is mainly equipped with Arduino, MOSFETs and DC bulbs as microcontroller, high-speed switching and load, respectively. As a result, the proposed sequential load switching method is highly effective since it has successfully extended the standby time period up to approximately 27 times longer, before the system shutdowns at the cut-off voltage.

In this paper, fabrication process of epoxy resin-barium titanate nanocomposite and measurement of its complex permittivity are presented. The material is prepared by mechanical mixing of epoxy resin and barium titanate nanopowder. The nanocomposite is intended to be used as high permittivity microstrip antenna substrate, which requires accurate measurement of its electrical characteristics. Thus, characterization of materials is done using waveguide technique, which does not require a precise machining of sample’s width and thickness, and does not utilize small reflection coefficient, which can cause error in measurement. The complex permittivity of the nanocomposite is measured in G-band (4 to 6 GHz). Then, the measured values are compared with prediction method, Lichtnecker and Maxwell-Garnet method. The results show that the measured permittivity of composite materials are in good range with prediction method, while the measurements of loss tangent show that the developed materials are low-loss and suitable to be used as substrate of antenna.

An accurate forecasting system is extremely crucial in order to simulate an optimum output level of photovoltaic (PV) power production for the next day. In this study, a relatively high-precision model of solar irradiance forecasting based on grid point value (GPV) datasets using relative humidity, precipitation, and three-level cloud covers parameterization has been conducted in Hitachi and four main cities in Japan. In the case of cloudy/rainy/snowy days, the influence of liquid water path is further introduced to the model. As a result, correlation coefficient $r$ of 0.94, 0.91, 0.91, 0.89, and 0.92 have been obtained using 21UTC forecast version in 2012 datasets for Hitachi, Tokyo, Nagoya, Osaka, and Fukuoka, respectively. Surprisingly, although the earlier forecast version, using 9UTC datasets, was later applied to the model, there was no significant change to the $r$ for these five locations as their values reduced by only approximately 0.01 at most. Furthermore, a similar trend has also been observed for the 2013 datasets from a comparison of 21UTC and 9UTC versions, which highly supports the fact that this model is reliable, since it still remains in a high-precision state even in the case where the earlier datasets of previous day are used.