Electrical and Electronics

The global electrical energy consumption is rising and there is a steady increase of the demand on the power capacity, efficient production, distribution and utilization of energy. Power electronics, the technology of efficiently processing electric power, play an essential part in the integration of the dispersed generating stations for higher efficiency and better performance of the power systems. This project deals with the simulation of grid connected inverter for Photovoltaic applications. Space vector pulse width modulation (SVPWM) technique has been adopted for generating pulses for the two level inverter. The entire system comprising of Photovoltaic array (PVA) and two level inverter has been developed in Mat lab-Simulink. The PVA model characteristics including the effects of temperature and solar irradiation change on maximum power point are also presented in this paper. The inverter output has been synchronized with the grid using d-q theory and the power flow is controlled at 200kw. Finally, the inverter has been tested in grid connected mode.

The key factor in video processing is the Video Compression (VC) which makes video signal to be processed and stored efficiently. Video compression involves complex algorithms such as Motion Estimation (ME). The hardware implementation of motion estimation has a trade-off between area, speed and Power Dissipation (PD). This paper implements high speed low complexity Variable Block Size Motion Estimation (VBSME) for H.264 standard using verilog coding on Altera Stratix – IV Field Programmable Gate Array (FPGA) (EP4SGX70DF29C2X) device, using parallel and pipeline timing approach to achieve high speed and the low complexity for High Definition Television (HDTV) system. The proposed work computes all 41 vectors of various block sizes during 180 clock cycles with less complexity using only 46 Processing unit Elements (PEs) and achieves a maximum operating frequency of 486.62 MHz.

Here, a equilateral triangular shaped circular feed network is designed. This circular feed network can radiate in eight different directions. This radiation is depending on four inputs ports which are excited. It can cover wide area within upper hemisphere. This antenna is designed in such a way that it is useful for any applicable GHz ISM band frequency and utilizes a suspended FR4 substrate. For this antenna we used positive microstrip elements, so that it will make easy to manufacture.

In this research, optimization of electromagnetic shielding tester process parameters for conducting textile composite materials through Taguchi design and ANOVA has been reported. The electromagnetic shielding tester process parameters were selected to optimize the EMSE. The effect of the size of the test Conductive Textile Material Composite sample on EMSE, effect of distance between Conductive Textile Material Composite sample and transmitting antenna on EMSE, effect of distance between the Conductive Textile Material Composite sample and receiving antenna on EMSE, and effect of RH% on EMSE were analyzed and optimized by Taguchi design and ANOVA. It was observed that the electromagnetic shielding effectiveness of conductive textile Composite materials were dominantly influenced by Conductive Textile Material Composite sample size and significantly influenced by distance between Conductive Textile Material Composite sample and transmitting antenna.

Binary pseudo random noise sequences are sequences of 1’s and 0’s having properties which make them appear to be noise-like but yet are deterministic. The NO-Kumar sequences were discovered by Jong-Seon No and P.V.Kumar and are known to have optimal correlation properties and a large linear span. The families of NO sequences are periodic with period = 2n-1 where ‘n’ is an even integer and contain within them a GMW sequence and also small set of Kasami sequences as special case. In this paper we investigate the properties of these sequences such as balance, run and even correlation properties. Odd correlation properties of these sequences which are not described in the NO-Kumar paper are also highlighted. The sequences are first simulated in MATLAB and then implemented by writing a Verilog code on the Nexys 4 FPGA board.

The main goal of this study is finding optimal place of unified power flow controller (UPFC) and phase shifter (PST) in the power systems. In other words, the main concentration is on connecting FACTS and OPF tools opinion using PST and UPFC power injection model to find the best place of setting these elements in power networks. The objective function of maximizing static voltage stability edge (system loadability factor) is discussed in this paper. Simulation results are offered on IEEE 118_ bus standard network and they suggest that proposed algorithm includes the better resolution and there is a more little time than the other placement methods.

In order to increase the ultrasonic trapping efficiency of bioparticles, a new cylindrical acoustic cavity with a concentric stainless cylindrical steel reflector for trapping and separation of bioparticles was designed and constructed. The resonant modes in this cavity were estimated by theoretical modeling and verified experimentally. For all bioparticles under study (RBC's, yeast and E-C0li), the simulation and measurement results were well agreed. Results obtained indicated that trapping efficiency reached 94% for RBC's at ultrasound intensity of 3 w/cm2. Acoustic contrast factor changed according the density of bioparticles and suspended medium. So it is possible to separate particles with different densities.

Voltage instability is the major concern of power system stability. It is caused due to the deficit of reactive power in the system. Improving the systems voltage by increasing the reactive power handling capacity of the system by using Static VAR Compensator, during a large disturbance is the area of study. The simulations are carried out for IEEE 14 bus system by using MATLAB/PSAT software. The result shows the effectiveness of SVC to improve the voltages when connected to a system.

In this work design and development of the conformal microstrip antenna array is demonstrated. Important system parameters and overall performance of the Array antenna is described and experimental results for reflection coefficients and far field patterns is included as well as simulated pattern and synthesis results .To improve the performance of microstrip antenna array, a modified configuration of microstrip series-fed taper array is designed. Compared to the traditional one, the novel antenna array has a better VSWR characteristic. The design procedure of the conformal antenna array is discussed and some valuable results are acquired. Numerical results are obtained and a very good agreement is observed between experimental and simulated results of such arrays.

For high bit rates and long haul optical communication systems using a single-mode fiber, a modulator with low chirp and small size are demanded. An electro-absorption modulator is very attractive because it has some advantages of not only low chirp and small size but also the elimination of polarization control through monolithic integration with a distributed feedback (DFB) laser. The modulation bandwidth of traditional lumped electro-absorption modulators (EAMs) is usually limited by the RC time constant, but the effective resistance R and capacitance C are not easily extracted for advanced device geometries. This paper has presented the important transmission characteristics of EA modulators such as transmission performance efficiency, insertion loss, extinction ratio, , over wide range of the affecting parameters for different selected electro-absorption materials to be the major of interest.