Power and Energy Commons^™

Technical Comparison Of Harmonic Mitigation Techniques For Industrial Electrical Power Systems, Almoataz Abdelaziz

Almoataz Youssef Abdelaziz

Power system harmonics cause many problems like equipment failures, malfunctions and plant shutdowns. Accordingly, mitigation of these harmonics is considered an important target especially for the industrial applications where any short downtime period may lead to great economic losses. There are at least ten different mitigation techniques to choose from, each with specific technical advantages and disadvantages. Comparative studies for the harmonic mitigation techniques in industrial electrical systems are rarely found in the literature even though they are strongly needed. This paper, almost for the first time, provides comprehensive technical comparisons between the various practical harmonics mitigation techniques in the …

Detection Of Line Outage In Transmission Networks Using Phasor Measurement Units Aided By Support Vector Machine Algorithms, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Many protection applications are based upon the Phasor Measurement Units (PMUs) technology. Therefore, PMUs have been increasingly widespread throughout the power network, and there are several researches have been made to locate the PMUs for complete system observability. This paper introduces an important application of PMUs in power system protection which is the detection of single line outage. In addition, a detection of the out of service line is achieved depending on the variations of phase angles measured at the system buses where the PMUs are located. Hence, a protection scheme from unexpected overloading in the network that may lead …

Protection Schemes Based On Support Vector Machine For Thyristor Controlled Series Compensated Transmission Line, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Recently, series compensation is widely used in transmission. However, this creates several problems to conventional protection approaches. This paper presents overcurrent and distance protection schemes, for fault classification in transmission lines with thyristor controlled series capacitor (TCSC) using support vector machine (SVM). The fault classification task is divided into four separate subtasks (SVMa, SVMb, SVMc and SVMg), where the state of each phase and ground is determined by an individual SVM. The polynomial kernel SVM is designed to provide the optimal classification conditions. Wide variations of load angle, fault inception angle, fault resistance and fault location have been carried out …

Phasor Measurement Units (Pmus) Based Fault Location Of Series Compensated Transmission Lines, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Phasor Measurement Units (PMUs) have gained a great popularity in the field of control and wide area protection during the last decade. One of the major protection applications based on PMUs technology is to determine the fault location in a transmission line. Therefore, several researches have been developed in the field of fault location. Some of the researches are based on one-end measurements. But, a greater accuracy has been achieved on the basis of two-end measurements. Many researchers suggested only voltage measurements to avoid the current transformers (CT) errors. While, others suggested methods depend on both voltages and current measurements …

Optimal Pmu Placement For Complete Observability Using Heuristic Methods, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

An essential tool for power system monitoring is state estimation. Phasor Measurement Units (PMUs) can greatly improve the state estimation process. However, for state estimation, the PMUs should be placed appropriately in the network. The problem of optimal PMU placement for full observability is analyzed in this paper. The objective of the paper is to minimize the size of the PMU configuration while allowing full observability of the network. At first, an optimal measurement set is determined to achieve full power system observability with ignoring zero injection buses. Then, the derived schemes are modified to maintain the observability after considering …

Transient Security Classification Using Gene Expression Programming Algorithm, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

No abstract provided.

Mle+: A Tool For Integrated Design And Deployment Of Energy Efficient Building Controls, Willy Bernal, Madhur Behl, Truong Nghiem, Rahul Mangharam

Madhur Behl

We present MLE+, a tool for energy-efficient building automation design, co-simulation and analysis. The tool leverages the high-fidelity building simulation capabilities of EnergyPlus and the scientific computation and design capabilities of Matlab for controller design. MLE+ facilitates integrated building simulation and controller formulation with integrated support for system identification, control design, optimization, simulation analysis and communication between software applications and building equipment. It provides streamlined workflows, a graphical front-end, and debugging support to help control engineers eliminate design and programming errors and take informed decisions early in the design stage, leading to fewer iterations in the building automation development cycle. …

Green Scheduling For Radiant Systems In Buildings, Truong X. Nghiem, Madhur Behl, George J. Pappas, Rahul Mangharam

Madhur Behl

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Green Scheduling For Radiant Systems In Buildings, Truong Nghiem, Madhur Behl, George Pappas, Rahul Mangharam

Rahul Mangharam

In this report we look at the problem of peak power reduction for buildings with electric radiant floor heating systems. Uncoordinated operation of a multi-zone radiant floor heating system can result in temporally correlated electricity demand surges or peaks in the building’s electricity consumption. As peak power prices are 200-400 times that of the nominal rate, this uncoordinated activity can result in high electricity costs and expensive system operation. We have previously presented green scheduling as an approach for reducing the aggregate peak power consumption in buildings while ensuring that indoor thermal comfort is always maintained. This report extends the …

Fuzzy Based Load Shedding Against Voltage Collapse, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

The phenomenon of voltage collapse eclipses a potential hazard for the transmission and distribution systems. The load shedding for avoiding the existence of voltage instability in power systems is taken as a remedial action during emergency states. The load shedding strategy for power systems with location and quantity of load to be shed is presented in this paper. Two methods are used for this purpose. The first method is based on a mathematical calculation of an indicator of risk of voltage instability. The second method is based on a fuzzy load shedding based algorithm that uses a voltage stability indicator …

Fast Thermal Generation Rescheduling, F. Eugenio Villaseca, B. Fardanesh

F. Eugenio Villaseca

A new dynamic programming algorithm for fast rescheduling thermal generation is presented. The savings in computational times are brought about by the introduction of two new techniques: the variable truncation dynamic programming and the limitation of the solution space to be searched. Several examples on a 20 machine system are used to illustrate the application of the algorithm and to show that optimal solutions are obtained at significantly reduced computational times.

Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …

Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …

Dynamic Companion Harmonic Circuit Models For Analysis Of Power Systems With Embedded Power Electronics Devices, H. Garcia, M. Madrigal, B. Vyakaranam, Rick Rarick, F. Eugenio Villaseca

F. Eugenio Villaseca

In this paper a methodology that extends the dynamic harmonic domain (DHD) analysis of large networks is presented. The method combines DHD analysis and discrete companion circuit modeling resulting in a powerful analytic technique called dynamic companion harmonic circuit modeling. It provides for a complete dynamic harmonic analysis of the system while preserving the advantages of discrete companion circuit models. The methodology is illustrated by its application to a three-node power system, where reactive power compensation is achieved using a fixed-capacitor, thyristor-controlled reactor (FC-TCR) and its control system.

Storage And Delivery Constrained Unit Commitment, Y. Al-Kalaani, F. Eugenio Villaseca, F Renovich Jr

F. Eugenio Villaseca

A general formulation and the development of a dynamic programming algorithm to solve a fuel-constrained unit commitment problem is presented. The system under consideration has oil units with storage constraints, gas units with delivery constraints, and unconstrained coal units. An optimal approach to transfer the fuel delivery constraints into unit capacity limits using a closed-form dual dispatch is introduced. As a result, the gas units can be viewed as fuel-unconstrained, thus greatly reducing complexity. It is shown that the optimization problem, which requires that storage levels be parameterized, leads to two different dispatch rules. The oil units are dispatched to …

Transient Stability Hierarchical Control In Multimachine Power Systems, A Rubbai, F. Eugenio Villaseca

F. Eugenio Villaseca

The authors present the optimal transient stability control problem in a hierarchical structure for multimachine power systems. The two-level structure retains the local closed-loop controls, thereby easing its implementation on existing systems. The formulation accounts for nonlinearities and interconnections, and the optimization of the system transient performance is obtained with less computational effort. Since the computations are distributed among the many local feedback subsystems, the storage and solution times are considerably less than those required by a single overall centralized controller. This advantage becomes much stronger as the system size increases. For illustration purposes, this technique was applied successfully to …

Two-Step Optimal Thermal Generation Scheduling, B Fardanesh, F. Eugenio Villaseca

F. Eugenio Villaseca

A new approach to the solution of the optimal thermal generation scheduling problem is presented. The problem is solved in two steps. As a first step, the optimal production schedule for the next day is obtained based on a daily load forecast, reserve capacity requirements, and present status of generating units. The second-step algorithm uses the results of the first step and adjusts the previous schedule to meet new constraints developed during the course of the day. Variable truncation dynamic programming is proposed as a new method to reduce computation effort. To eliminate the need for solving the entire problem …

Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer

F. Eugenio Villaseca

A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presented

Evolution Of A Folded Floating-Gate Differential Pair, Bradley Minch

Bradley Minch

The author presents a folded floating-gate MOS (FGMOS) differential pair circuit that is capable of simultaneously providing a rail-to-rail common-mode input voltage range and a rail-to-rail output voltage swing with a low power-supply voltage. In this configuration, the voltage drop across the bias current source is folded up into the same range over which the output voltages swing, facilitating low-voltage operation. The floating-gate charge can be used to trim out the offset voltage of the differential pair and to reduce the required power-supply voltage for a given bias current level. The author provides both a qualitative description of how the …

Switch Yard Operation In Thermal Power Plant(Katpp Jhalawar Rajasthan), Radhey Shyam Meena Er.

Radhey Shyam Meena

Switchyard Provides the facilities for switching ,protection & Control of electric power. To handle high Voltage power with proper Safety measures. To isolate the noises coming from the grid with true 50Hz power SWITCH YARD IS IMPORTANT PART IN THERMAL PLANT. IN KALISINDH THERMAL 400KV AND 220KV SWITCH YARD LOCATED.

Capacitively Coupled Radio-Frequency Discharges In Nitrogen At Low Pressures, L. L Alves, L. Marques, C. D Pintassilgo, W. Wattieaux, Et. Es-Sebbar, J. Berndt, E. Kovačević, N. Carrasco, L. Boufendi, G. Cernogora

Dr. Et-touhami Es-sebbar

This paper uses experiments and modelling to study capacitively coupled radio-frequency (rf) discharges in pure nitrogen, at 13.56 MHz frequency, 0.1–1 mbar pressures and 2–30 W coupled powers. Experiments performed on two similar (not twin) setups, existing in the LATMOS and the GREMI laboratories, include electrical and optical emission spectroscopy (OES) measurements. Electrical measurements give the rf-applied and the direct-current-self-bias voltages, the effective power coupled to the plasma and the average electron density. OES diagnostics measure the intensities of radiative transitions with the nitrogen second-positive and first-negative systems, and with the 811.5 nm atomic line of argon (present as an …

Contingency Assessment Under Uncertainty For Voltage Collapse And Its Application In Risk Based Contingency Ranking, Venkat Krishnan

Venkat Kumar Krishnan

No abstract provided.

Ionization Photophysics And Rydberg Spectroscopy Of Diacetylene, M. Schwell, Y. Benilan, N.. Fray, M.-C. Gazeau, Et. Es-Sebbar, F.-G. Levrel, N. Campion, S. Leach

Dr. Et-touhami Es-sebbar

Photoionization of diacetylene was studied using synchrotron radiation over the range 8–24 eV, with photoelectron-photoion coincidence (PEPICO) and threshold photoelectron–photoion coincidence (TPEPICO) techniques. Mass spectra, ion yields, total and partial ionization cross-sections were measured. The adiabatic ionization energy of diacetylene was determined as IEad = (10.17 ± 0.01) eV, and the appearance energy of the principal fragment ion C4H+ as AE = (16.15 ± 0.03) eV. Calculated appearance energies of other fragment ions were used to infer aspects of dissociation pathways forming the weaker fragment ions , C3H+, and C2H+. Structured autoionization features observed in the PEPICO spectrum of diacetylene …

Dynamic Modeling And Analysis Of Single-Stage Boost Inverters Under Normal And Abnormal Conditions, Ali Kaviani

Ali Kaviani

No abstract provided.

Optimization Of Shallow Foundation Using Gravitational Search Algorithm, Mohammad Khajehzadeh, Mohd R. Taha, Ahmed El-Shafie, Mahdiyeh Eslami

Dr. Mahdiyeh Eslami (مهدیه اسلامی)

No abstract provided.

Development Of Stability Protection Framework In Oman Electricity Transmission System, Omar H. Abdalla, Thani Al-Khusaibi, Adil Al-Batashi, Anil Kumar, A. Svalovs, P. Watson, I. Svalovs

Omar H. Abdalla

Volatile Products Controlling Titan’S Tholins Production, N. Carrasco, T. Gautier, Et. Es-Sebbar, P. Pernot, G. Cernogora

Dr. Et-touhami Es-sebbar

A quantitative agreement between nitrile relative abundances and Titan’s atmospheric composition was recently shown with a reactor simulating the global chemistry occurring in Titan’s atmosphere [Gautier et al. (2011) Icarus, 213: 625]. Here we present a complementary study on the same reactor using an in-situ diagnostic of the gas phase composition. Various initial N2-CH4 gas mixtures (methane varying from 1 to 10%) are studied, with a monitoring of the methane consumption and of the stable gas neutrals by in-situ mass spectrometry. Atomic hydrogen is also measured by optical emission spectroscopy. A positive correlation is found between atomic hydrogen abundance and …

Application Of Modern Control Theory For The Power-System Analysis And Control, Mulukutla S. Sarma, Earl D. Eyman

Sarma Mulukutla

With the current rise in the demand of electrical energy, present-day power systems which are large and complex, will continue to grow both in size and complexity. Also, our dependence on electrical energy is so great that it is essential to have uninterrupted supply of electrical power within set limits of frequency and voltage levels, and that it becomes a dire necessity to develop methods for effective control and operation of power systems. Modern control theory concepts have been effectively used and will continue to be utilized for the power system analysis and control. This paper attempts in assessing the …

On-Line Optimum Load Scheduling Of Power Systems Using Modified Fletcher-Powell Method, Divakaruni P. Sudhakar, Mulukutla S. Sarma

Sarma Mulukutla

The problem of optimum power dispatch has been the object of constant attention of power-system engineers in modern times and its importance is understandably enhanced in these times of energy shortage. This paper presents a new approach for obtaining on-line optimum load scheduling of power systems. The suggested algorithm could be used in conjunction with any standard load-flow routine, requiring little additional core storage. The output of the load-flow program is utilized to acquire a first hand knowledge of the total losses in an integrated power system, which in turn enables one to make an accurate estimate of the loss …

Vuv Photoionization Of Acetamide Studied By Electron / Ion Coincidence Spectroscopy In The 8-24 Ev Photon Energy Range, M. Schwell, Y. Bénilan, N. Fray, M.-C Gazeau, Et. Es-Sebbar, Gustavo A. Garcia, L. Nahon, N. Champion, S. Leach

Dr. Et-touhami Es-sebbar

A VUV photoionization study of acetamide was carried out over the 8-24 eV photon energy range using synchrotron radiation and photoelectron/photoion coincidence (PEPICO) spectroscopy. Threshold photoelectron photoion coincidence (TPEPICO) measurements were also made. Photoion yield curves and branching ratios were measured for the parent ion and six fragment ions. The adiabatic ionization energy of acetamide was determined as I.E (12A’) = (9.71±0.02) eV, in agreement with an earlier reported photoionization mass spectrometry (PIMS) value. The adiabatic energy of the first excited state of the ion, 12A”, was determined to be ≈ 10.1 eV. Assignments of the fragment ions and the …