Electrical and Electronics

This paper investigates the performance of an 11 kV silicone rubber (SiR) outdoor insulator when subjected to an alternative voltage at 50 Hz. The electrical field and potential distributions over the insulator surface were computed and analysed using the Finite Element Method (FEM) COMSOL Multiphysics software. Comparative studies of field and equipotential contours for the insulator under dry clean and uniformly contaminated surface conditions are presented. The surface power dissipation along insulator surface is calculated. The critical of high field regions on SiR surfaces were identified and the power dissipated in the pollution layer along insulator profile was revealed. This study showed useful information about the surface heating which, might be help to predict any dry band formations along the leakage path of the insulator and to evaluate the insulator characteristics and its behavior.

A high gain microstrip patch fed horn antenna operating in C-band at 6 GHz is presented. The proposed antenna uses H-shaped microstrip excited patch in FR4 and a surface mounted horn integrated on metal. The peak antenna gain is 8.6dBi and directivity is 8.9dBi. VSWR bandwidth is 24%. The proposed design is simulated with Zeland Program Manager IE3D 9.0 version software.

Research and development in electronics and its allied subjects have changed life styles of modern society. Though modern man has got many physical and mental comforts from exponential revolution in consumer electronics products, they did bring in some hazardous side effects on environment and human health. Disposal of E-waste has become a major problem across the world and is growing at alarming proportions. The accumulation of e-waste causing biggest harm to environment is the dumping of hazardous materials. The main aim of this theoretical concept research paper is to study, analyse, discuss existing E-waste recycling methodologies and conceptualise and formulate an ideal permanent technical solution for E-waste hazards faced by all nations across the world. Future projections of ever increasing E-waste for India, China, Europe, USA and the world for 2050 are included in this paper. In this paper a known novel recycling technical solution is re-invented through which 100% E-waste is processed to extract each and every material used in the fabrication process. An attempt is made to present and discuss an ideal technical solution which will give rise to discarding of E-waste into environment is either nil or minimal. At the same time it is expected to result in employment generation with marginal profits and surely acceptable to all players of consumer electronics industry. Implications of implementation of proposed ideal technical solution, commercial and societical are also included here.

A Novel type of analog divider is described. The circuit enables division of a dc voltage with another dc voltage. The constant of division is dependent upon two resistor values. Employing precision resistors, an acceptable level of accuracy can be obtained in the division. Verification of the feasibility of the circuit configurations are established by way of test results on a proto type.

Irrigation is the artificial application of water to land or soil. It is used to assist in growing of agricultural crops, protection of plant against frost, preventing soil consolidation, maintenance of landscapes, and re-vegetation of distributed soils in dry areas and during periods of inadequate rainfall. Many of the irrigation systems operated worldwide are used on farms or lands that are located on the outskirts of towns and difficult to monitor. The manual operation of these systems over time has resulted in either under watering or over supply of water. The consequence of which are reduced crop yield and withering of crops respectively. Over irrigation further results in leaching of soil nutrients. The manual approach to practicing irrigation is both cost and resource inefficient. To address these challenges an efficient and cost effective microcontroller based irrigation control system designation is proposed for enhancing food security.

This paper presents the impact of Unified Power Flow Controller (UPFC) on transient stability improvement in the Nigeria 330KV transmission network. UPFC is a Flexible AC Transmission System controller (FACTS) that can regulate the Power flow through the Line by controlling its Series and shunt reactance. In shunt connection it has Static Synchronous Compensator (STATCOM) and in the series, Static Synchronous Series Compensator (SSSC) is employed and can independently control the Line Power Flow in order to improve transient stability of the system. This network which consist of 17 generating stations, 41 buses and 40 transmission lines was modeled and simulated using PSAT and Matlab Version 7.5. Fault was initiated with and without UPFC and result showed that Transient Stability of the system is improved.

Multilevel inverters are used extensively in many applications due to their increased power rating, improving harmonic performance and reduced electromagnetic interference. However, the usage of more switches in the conventional configuration poses a limitation to its wide range application. This may leads to vast size and price of the inverter is very high. So in order to overcome this problem the new multilevel inverter is proposed with reduced number of switches. The configuration of the PV system is based on the multi-string technology and the maximum power point is obtained using PSO Algorithm. The output of the MPPT tracker controls the duty cycle of the boost converter. To control this power converter, SVPWM based modulation technique is implemented. The results are validated through the harmonic spectrum of the FFT window by using Matlab/simulink.

One of the most important and challenging issues in wireless sensor networks (WSNs) is to optimally manage the limited energy of nodes without degrading the routing efficiency. In this paper, we propose an Energy-Efficient Adaptive routing mechanism (EE-ARM) for WSNs which saves energy of nodes by removing the much delayed packets without degrading the real-time performance of the used routing protocol. It uses the adaptive transmission power algorithm which is based on the attenuation of the wireless link to improve the energy efficiency. Integrated in PATH, the well known real-time routing protocol based on two-hop neighbourhood information, the results show that the proposed routing mechanism perform good in terms of energy consumption, Deadline miss ratio (DMR) and end-to-end delay.

A micro strip-fed monopole antenna for ultra-wideband antenna with triple band notched and WLAN antenna is presented and analyzed in detail. In the UWB antenna three different frequencies are notched by means of using E-shaped resonator. The three notched frequencies are 3.6 GHz (WLAN), 5GHz (WLAN) and 10 GHz (X- band) with a reference level of s11 > -10dB. The center frequency of the notched band is 7 GHz. The frequency band of the proposed antenna is 0 GHz-11GHz for voltage standing wave ratio (VSWR) less than 2.Surface current distributions and transmission line models are used to analyze the effect of these slots. The antenna is successfully fabricated and measured, showing broad band matched impedance and good Omni directional radiation pattern. The designed antenna patch has a compact size of 17x13.8 mm2.

A single feed compact rectangular microstrip antenna is presented in this paper. L & H slits are introduced on the edge of the patch to study the effect of the slit on radiation behavior with respect to a conventional microstrip patch. The resonant frequencies are obtained at 2.21, 2.4, 4.36 & 6.41 GHz with corresponding bandwidth 15.18 MHz, 11.85 MHz, 15.14 MHz, 78.91 MHz and return loss of about -23.62, -13.58, -11.46 & -15.65 dB respectively. The antenna has been reduced by 61% when compared to a conventional rectangular microstrip patch. The characteristics of the designed structure are investigated by using MoM based electromagnetic solver, IE3D.