Effect of Contaminant Flow-rate and Applied Voltage on the Current Density and Electric Field of Polymer Tracking Test

Electrical failure due to surface discharge on the insulation material will cause material degradation and eventually lead to system failure. The flow of leakage current (LC) on the insulator surface under wet contamination is used to determine the material degradation level. According to IEC 60587 standard, LC exceeding 60 mA for more than two seconds is considered as failure. In this study, the  electric field and current density distributions on the linear low-density polyethylene (LLDPE) and natural rubber blend material have been analyzed using finite element method (FEM) analysis. The physical parameters used in FEM simulation were applied with voltage and contaminant flow rate, in accordance to contaminant conductivity. Tracking test condition according to IEC 60587 standard has been applied as proposed by the reference work in simulation using QuickField FEM software. The results show that the electric field and current density would become critical in higher applied voltage and contaminant flow rate. The highest average and highest maximum current density and electric field are found in both applied voltage of 6 kV and contaminant flow rate of 0.90 mlmin-1

Performance evaluation of multiple-beam free space optics in tropical rainy weather

Free space optics (FSO) has the potential to replace optical fiber as a solution for the last mile problem. FSO is favored because of its cheap maintenance costs and quick deployment time as compared to other communication system such as fiber optics. Atmospheric attenuation is a problem for FSOs with classic single beam systems, especially when it rains heavily specially in tropical region like Malaysia. As a result, a multibeam FSO transceiver system has become popular as a solution to this problem. The purpose of this study is to compare the standard single beam FSO system with the suggested multibeam FSO system. At a bit error rate (BER) of 10-9, the comparison is made in terms of received optical power, channel distance, and geometrical losses. Rain intensity data is gathered over a six-month period. To evaluate the performance of both systems, the average rain attenuation is calculated from this data and exposed to single beam and multibeam FSO systems. The multibeam FSO approach was found to increase the system's performance. The results show that employing up to four beams improves the quality of received power and increases the channel distance to 1150 m when compared to a single beam FSO system with a channel distance of only 830 m

Solar-wind power generation system for street lighting using Internet of Things

Every country is subsidising millions of dollars for street lighting as those are connected to the grid. Besides, the generation of electricity comes from fossil fuels with emissions of carbon dioxide (CO2). Therefore, alternative generation of electricity can be done by using a hybrid system. Solar energy starts as the day begins, and the wind is accessible on the streets with a to-and-fro motion of the car. It does not rely on any factor. This hybrid system generates 12 V direct current (DC), whereas no alternating current (AC) converters are used, resulting in a reduction the system's cost. The control system was constructed based on internet of things (IoT) and included the most sophisticated battery charging system to improve the battery's cells' life cycle. The hardware system has been simulated using easy electronic design automation (EasyEDA) and incorporated with the printed circuit board (PCB) design. The prototype is constructed alongside collected data to compare with the theoretical basis towards net-zero energy street lighting (nZESL). The prototype was able to lead to nZESL and backup stability of the system is 10 hours per day, along with the validation of theoretical analyses and effectiveness of the system. The system has the potential to make a significant contribution to lowering CO2 emissions and government subsidies for street lighting

Identification of acoustic signals of surface discharges on glass insulator under different contamination levels

Surface discharge is a common phenomenon that normally occurs on the insulator surface under wet contamination condition. The generation of small sparks from the surface discharge would develop many types of signals. In this work an acoustic method is used to detect and capture the signals of surface discharges. The tests were carried out on cleaned and polluted glass insulators by using surface tracking and erosion test procedure of IEC 587. Three conditions of contamination levels were considered, which are light, medium and heavy based on ESDD levels. A laboratory experiment was done by making the models of these discharges. The test equipment including antennas as a means of detection and digital processing techniques for signal analysis were used. Wavelet signal processing was used to recover the surface discharge acoustic signal by eliminating the noises of many natures. Experimental results shows that the actual signals of surface discharge are related to the levels of insulator contamination

Characterization of leakage current on high voltage glass insulators using wavelet transform technique

The measurement and analysis of leakage current (LC) for condition-based monitoring and as a means of predicting flashover of polluted insulators has attracted a lot of research in recent years. Leakage current plays an important role in the detection of insulator's condition. This paper proposes a method for reducing the noise included in the current signal. The tests were carried out on cleaned and polluted glass insulators by using surface tracking and erosion test procedure of IEC 60587. Wavelet analysis method is used to compress the leakage current data. Experimental results shows that the actual signals of leakage current are related to the levels of insulator contamination

A survey of Free Space Optics (FSO) communication systems, links, and networks

The next generation (NG) optical technologies will unveil certain unique features, namely ultra-high data rate, broadband multiple services, scalable bandwidth, and flexible communications for manifold end-users. Among the optical technologies, free space optical (FSO) technology is a key element to achieve free space data transmission according to the requirements of the future technologies, which is due to its cost effective, easy deployment, high bandwidth enabler, and high secured. In this article, we give the overview of the recent progress on FSO technology and the factors that will lead the technology towards ubiquitous application. As part of the review, we provided fundamental concepts across all types of FSO system, including system architecture comprising of single beam and multiple beams. The review is further expanded into the investigation of rain and haze effects toward FSO signal propagation. The final objective that we cover is the scalability of an FSO network via the implementations of hybrid multi-beam FSO system with wavelength division multiplexing (WDM) technology