Electrical and Electronics

Rising demands on engine performance, fuel consumption, emission, etc. leads to study thermal behavior of cooling system in engines precisely. To minimize the time of 3-D numerical simulation, single phase boiling approach was used. Sub-cooled boiling heat transfer consists of two components (i.e. forced convection and boiling). The convective component is evaluated from flow analyses and to evaluate boiling heat transfer, two popular models, Chen and BDL, are considered. To study sub-cooled boiling heat transfer in engine cooling passages, a rectangular, bottom-heated, horizontal duct is simulated here to assess the effects of different working conditions (i.e. pressure, velocity and coolant type) on heat transfer. Comparing the numerical results with the experimental ones reveals that Chen model is more precise than BDL in predicting boiling heat transfer in engine cooling system.

For some decades, power quality did not cause any problem, because it had no effect on most of the loads connected to the electrical distribution system. Voltage sags is the most common type of power quality disturbance in the distribution. Recently various power electronic devices are proposed for this purpose. Among these devices special attention was given to the family based on the VSC technology for faster response. This project intends to investigate mitigation technique that is suitable for different type of voltage sags source with different type of loads. The mitigation techniques that will be studied are such as Dynamic Voltage Restorer (DVR), Distribution Static Compensator (DSTATCOM). The simulation is done using PSCAD/EMTDC software.

The paper presents the modeling, simulation & analysis of Speed Controller for a Brushless DC Motor. Performance comparison between a position sensor and sensorless based speed control is also presented in the paper. Hall effect Sensors have been used for position sensing and back emf based method has been used for determining the position of rotor in position sensorless scheme. The speed controller has been implemented by incorporating PI controller and hysteresis current controller in MATLAB Simulink. Hysteresis current controller was used to generate PWM pulses for inverter switches. IGBT based inverter was used for conversion of DC power to AC power.

In this paper we report simulation and experimental characterization of microstrip antenna that employs silver nanofilm as radiating patch. The bulk silver is deposited to a thickness of 30 nm using physical vapor deposition system. In this work non-contacting feed aperture coupled patch antenna is used in order to avoid soldering problem between nanofilm (ultrathin) and bulk copper feed thickness of 17 micron. The experimental result of fabricated nanofilm antenna shows wide bandwidth response over bulk patch antenna. Using nanofilm, an optimum bandwidth of 12% is obtained which is 50% higher than bulk patch antenna. The nanofilm antenna resonates around 6.5 GHz finds application in ‘C’ band frequency.

Cryptography circuits for portable electronic devices provide user authentication and secure data communication. These circuits should, in general, occupy small chip area, consume low power, handle several cryptography algorithms, and provide acceptable performance. This paper presents the simulation and synthesis of three standard cryptography algorithms on a universal architecture. The cryptography processor implements both private key and public key algorithms and meets the power and performance specifications. The mentor graphics modelsim tool is used for design and simulation and also Synopsys Design Compiler tool is used for synthesis. TSMC 65nm library is used for the synthesis.

Power system performance is a?ected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line, a rapid change of load or hydraulic transients. Accurate modeling of hydraulic governor-turbines is essential to characterize and diagnose the system response during an emergency. In this paper, the identification/development and implementation of hydraulic systems in power plants via literature survey and computer based simulations have been described and it has been analyzed with comparing different models. This article examines the responses of different models through simulation in MATLAB/SIMULINK. The results obtained provide an insight into the interaction between electrical and hydraulic system of hydro power plant governed by di?erent governor settings, so that the system may remain unaffected during any disturbance.

This paper presents the design and implementation of sharpening of maximally flat cascaded integrator comb compensation filters. Cascaded integrator-comb (CIC) digital filters are computationally efficient implementations of low pass filters. No multiplication characteristic makes them popular in hardware devices. The modified sharpened cascaded integrator comb compensation filter is used to improve magnitude response and gain. For narrow and wide-band compensation second-order and fourth-order linear phase filters are considered. Power-of-two decimation factors of CIC filter is M and number of adders are depends upon decimation factor. Closed form equations for the computation of the filter coefficients are provided. The new technique delivers gain and stop band attenuation correction comparable to existing techniques.

Various applications, like in underground mines and oil and gas industries, require remote operation of vector-controlled medium-voltage variable speed drives via a long motor feeder. The use of voltage source inverters in such cases leads to motor overvoltage and harmonic quality problems. The current source inverter (CSI) is ideally matched to these applications be-cause of its motor-friendly voltage output. Speed sensorless operation is mandatory due to the long motor feeder. Although the model reference adaptive system (MRAS) is a powerful and proven speed estimation tool, its implementation in long motor feeder drives faces many challenges. Among them, and addressed in this paper, are inherent dc offset in its stator model, the need for actual motor voltage and current values, and oscillations in the estimated speed due to errors in the motor current measurement signals. In this paper, a sensorless CSI vector-controlled drive, suitable for long motor feeder applications, is studied. Improved speed estimation is achieved by proposing 1) a modified dc-offset eliminator for an MRAS speed estimation and 2) a compensation technique for mo-tor current’s measurement errors. Intensive experimental results, for a low-voltage scaled model, along with simulations validate the effectiveness of the proposed technique. In this Proposed Control technique of the space vector modulation Technique (SVPWM) is applied to 5 level inverter controls in the proposed DTC_SVPWM based induction motor drive system, thereby dramatically reducing the torque ripple. Then the controller based on space vector modulation is designed to be applied in the control of Induction Motor (IM) with a three-level Inverter. This type of Inverter has Several advantages over the standard Five-level CSI, such as a greater number of levels in the output voltage waveforms, Lower dv/dt, less harmonic distortion in voltage and current waveforms and lower switching frequencies Eliminated By SVPWM Tech. simulation results are reported to demonstrate its effectiveness. The entire control scheme is implemented with Matlab/Simulink.

Electric distribution sub-stations have an important role in energy distribution management. The sub-stations transfer energy from 400V to 20000V in centre of consumption. More decision in utilizing of this sub-station is basically assert on one attribute and most of time some important aspects may be forget. In this paper, the analysis is done by using Analytical Heirachy Process (AHP) method (taking four basic attributes involving Load forecast, Land availability, Cost of land and closeness to load centre) for selecting the best suitable location for placement of sub-station so, an example of a place Greater NOIDA, India, is taken which will grow into metropolis by 2021 as presented in a survey. The place comprises all the major power consuming sectors viz. residential, commercial and industrial. As in this study, the intention is to optimize the position of sub-station for construction of a new sub-station. As to conclude of this study the decision will help the electric managers and designers to be able to get multi aspects of decision making and improve the design, locations and grid reconstruction of the distribution sub-stations.

The buildings situated on hill slopes in earthquake prone areas are generally irregular, torsionally coupled & hence, susceptible to serve damage when affected by earthquake ground motion. Such buildings have mass & stiffness varying along the vertical & horizontal planes, resulting the center of mass & center of rigidity do not coincide on various floors, hence they demand torsional analysis, in addition to lateral forces under the action of earthquakes. These unsymmetrical buildings require great attention in the analysis & design. Analysis of hill buildings is somewhat different than the buildings on leveled ground, since the column of hill building rests at different levels on the slope. The shorter column attracts more forces & undergoes damage, when subjected to earthquakes.