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Aiming at the problem of the torsional vibration in the vehicle transmission system, the particle swarm optimization algorithm was used to optimize the model parameter. According to the mechanical model of the electric vehicle transmission system, the dynamic equation of the transmission system is derived, and the simulation model of the transmission system is established. The particle swarm optimizationalgorithm is used to optimize the damping parameter in the model, and the simulation verification is performed. The simulation results show that the angular velocity and angular acceleration peaks of the motor shaft are reduced by 20.56% and 15.56% respectively, the angular velocity and angular acceleration peaks of the decelerator differential assembly are reduced by 20.37% and 15.56% respectively, and the angular velocity and angular acceleration peaks of the transmission half shaft are reduced by 18.75% and 23.67% respectively. The optimized peak has been significantly reduced by comparing the results, and the overall vibration amplitude has also been reduced. The model established in this paper has certain versatility, and the parameter modification is also convenient. This modeling and optimization analysis method provides a theoretical foundation for solving the torsional vibration problem of the vehicle transmission system. 

Power flow studies provide a systematic mathematical approach for determination of various bus voltages, there phase angle, active and reactive power flows through different branches, generators and loads under steady state condition. In this paper, the purpose of power flow analysis is to determine four bus system power flows. Case studies have been performed on Lawpita Taungoo Kamarnat Hlawga 230kV Line Myanmar. This paper presents a reliable method to meet the requirements by developing a Newton Raphson based load flow calculation program through which control setting of Shunt Compensator can be determined directly. This program computes the voltage magnitude and angle at each bus in a power system under balanced steady state conditions. Real and reactive power flows for all buses, as well as line flow and line losses, are also computed. And then the compensation of shunt capacitor is proposed for load flow analysis and also for overall loss minimization and improvement in system voltage profile.  by Wint Yu Yu Zaw "Power Flow Analysis for Four Buses System by NR Method"  Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019,  URL: https://www.ijtsrd.com/papers/ijtsrd23472.pdf Paper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/23472/power-flow-analysis-for-four-buses-system-by-nr-method/wint-yu-yu-zaw

Power flow studies provide a systematic mathematical approach for determination of various bus voltages, there phase angle, active and reactive power flows through different branches, generators and loads under steady state condition. In this paper, the purpose of power flow analysis is to determine four bus system power flows. Case studies have been performed on Lawpita Taungoo Kamarnat Hlawga 230kV Line Myanmar. This paper presents a reliable method to meet the requirements by developing a Newton Raphson based load flow calculation program through which control setting of Shunt Compensator can be determined directly. This program computes the voltage magnitude and angle at each bus in a power system under balanced steady state conditions. Real and reactive power flows for all buses, as well as line flow and line losses, are also computed. And then the compensation of shunt capacitor is proposed for load flow analysis and also for overall loss minimization and improvement in system voltage profile.  by Wint Yu Yu Zaw "Power Flow Analysis for Four Buses System by NR Method"  Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019,  URL: https://www.ijtsrd.com/papers/ijtsrd23472.pdf Paper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/23472/power-flow-analysis-for-four-buses-system-by-nr-method/wint-yu-yu-zaw

The high incidence of three-phase asynchronous motors (TAM) in global energy consumption and its influence on the operation of electrical systems makes it necessary to develop models that allow their analysis effectively. Based on this, this paper presents a universal model of TAM based on the relationship between the active and reactive power of the TAM and the deviation of voltage and frequency. It can be applied to any general-purpose TAM and is very useful when representing these motors in electrical power system studies. The model parameters were obtained from a statistical analysis performed on 70 TAM of different classifications. The results are validated by comparing them with those obtained from the solution of the equivalent circuit, demonstrating its validity by less than 6% errors. 

This paper presents the design and analysis of a relatively new wireless power transfer technique using capacitive coupling, named Capacitive power transfer (CPT). In general, CPT system has been introduced as an attractive alternative to the former inductive coupling method. This is because CPT uses lesser number of components, simpler topology, enhanced EMI performance and better strength to surrounding metallic elements. In this work, aluminium sheet is used as a capacitive coupling at transmitter and receiver side. Moreover, a Class-E resonant inverter together with π1a impedance matching network has been proposed because of its ability to perform the dc-to-ac inversion well. It helps the CPT system to achieve maximum power transfer. The CPT system is designed and simulated by using MATLAB/Simulink software. The validity of the proposed concept is then verified by conducting a laboratory experimental of CPT system. The proposed system able to generate a 9.5W output power through a combined interface capacitance of 2.44nF, at an operating frequency of 1MHz, with 95.10% efficiency. The proposed CPT system with impedance matching network also allows load variation in the range of + 20% from its nominal value while maintaining the efficiency over 90%.

A catalogue is presented of space shuttle electrical equipment as used within a standardized data base for EPS consumables analyses. The general function and expected usage of each type of electrical equipment are described, and the usage of specific equipment of each type in the performance of EPS consumables analyses is defined.

Machine-to-Machine (M2M) communication over the Long Term Evolution Advanced (LTE-A) networks has witness exponential growth and expansion in the last couple of years. This expansion has created an increase in the demand for high speed internet, multimedia messaging services, digital broadcasting etc, thus fuelling higher data traffic. The network operators in trying to meet this increasing demand injected more access points by deploying more Base Stations (BSs) to make the network denser. The BSs are the major consumers of energy in the wireless communication network due to the use of inefficient power amplifiers and therefore deploying more BSs into the network will increase the power consumption and the networks operational cost. The aim of this paper was to examine the power consumption patterns of the main elements in the BS, employ various techniques to reduce their power consumption, reduce the operational cost and improve the efficiency of the BS. 

This paper proposes a new and simple method to incorporate three-phase power transformer model into distribution system load flow (DSLF) analysis. The objective of the present work is to find a robust and efficient technique for modeling and integrating power transformer in the DSLF analysis. The proposed transformer model is derived based on nodal admittance matrix and formulated by using the symmetrical component theory. Load flow formulation in terms of branch currents and nodal voltages is also proposed in this paper to enable integrating the model into the DSLF analysis. Singularity that makes the calculations in forward/backward sweep (FBS) algorithm is difficult to be carried out. It can be avoided in the method. The proposed model is verified by using the standard IEEE test system.

This study analyses yearly and seasonal wind speed data recorded over eight years using Weibull distribution function and the direct power control application of a wind chain. The wind potential evaluation was carried out based on empirical model. Results show that, during the warm months the wind speed is uniform, constant and stable. In addition, it has been found that the use of a control strategy was necessary for extracting the optimum power. For this purpose, the second part of this work presents a direct power control (DPC) technique in order to adjust the produced active and reactive powers. The application and performance evaluation of the proposed control system implemented within the d-q reference framework has been exposed and discussed. The system modeling and the control diagram are built under MATLAB software. According to simulation results, the forward power control provides almost sinusoidal input waveform current, constant switching frequency operation, unity power factor regulation and also provides powers decoupling. As shown by simulation results, the suggested control method is efficient.

In distribution system, wind power plants are becoming popular renewable energy sources. It employs Doubly Fed Induction Generator (DFIG) to generate power based on wind conversion. Short and long transmission lines, presence of faults and presence of Static Synchronous Compensator (STATCOM) are highlighted issues in this paper. Basically, this research develops investigations on some electrical variables such as voltage and current to control them. Distribution Static Synchronous Compensator (DSTATCOM) is proposed in this paper. Wind farm acts as a source while DSTATCOM is connected to the distribution system with a DFIG based wind farm. The controller proposed is DSTATCOM is modeled and simulated in MATLAB/SIMULINK and the results are given. A microgrid based small signal analysis is performed in the laboratory using MATLAB and different comparisons are made and simulation case studies are presented and validated. 

This paper discusses the economic analysis and environmental impacts of integrating a photovoltaic (PV) array into diesel-electric power systems for remote villages. MATLAB Simulink is used to match the load with the demand and apportion the electrical production between the PV and diesel-electric generator. The economic part of the model calculates the fuel consumed, the kilo watt hours obtained per gallon of fuel supplied, and the total cost of fuel. The environmental part of the model calculates the particulate matter (PM), NOx and CO2 emitted to the atmosphere. Simulations were performed for three cases: 1) diesel only; 2) diesel-battery; and 3) PV with diesel-battery using a one-year time period. The simulation results were utilized to calculate the energy payback, the simple payback time for the PV module, and the avoided costs of CO2, NOx, and PM Ghanshyam Jayswal | Gagan Deep Yadav"Techno-Economic and Environmental Analysis of Wind-Diesel Power System" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-4 , June 2017, URL: http://www.ijtsrd.com/papers/ijtsrd157.pdf Article URL: http://www.ijtsrd.com/engineering/electrical-engineering/157/techno-economic-and-environmental-analysis-of-wind-diesel-power-system/ghanshyam-jayswal

A grid connected hybrid generation system (HGS) consisting of wind energy conversion System (WECS)/Photo voltaic (PV) System/solid oxide fuel cell (SOFC) is designed and simulated by using Matlab/Simulink. SOFC is the replacement of battery, attached to produce the clean energy when these renewable energy sources are unable to produce required amount of electric power. A controller is used to regulate the flow of H2 through the valve to the SOFC and the rest amount of H2 is stored in storage tank. Also, an operational control strategy (OCS) is developed to utilize maximum amount of power of PV to the required load and rest amount of power is coming from wind to fulfill the load demand. Hence, the electrolyzer is supplied by the wind power to convert the water in to H2 and oxygen. Also the power quality factor (PQF) analysis is exercised to measure the quality of power transmission.

A grid connected hybrid generation system (HGS) consisting of wind energy conversion System (WECS)/Photo voltaic (PV) System/solid oxide fuel cell (SOFC) is designed and simulated by using Matlab/Simulink. SOFC is the replacement of battery, attached to produce the clean energy when these renewable energy sources are unable to produce required amount of electric power. A controller is used to regulate the flow of H2 through the valve to the SOFC and the rest amount of H2 is stored in storage tank. Also, an operational control strategy (OCS) is developed to utilize maximum amount of power of PV to the required load and rest amount of power is coming from wind to fulfill the load demand. Hence, the electrolyzer is supplied by the wind power to convert the water in to H2 and oxygen. Also the power quality factor (PQF) analysis is exercised to measure the quality of power transmission.

Hybrid power technology plays an important role in the field of energy systems. This technology can be used with or without a grid by merging renewable and non-renewable sources. This study analyses electricity generation through an off-grid hybrid technology, which is composed of micro-hydro power and diesel generator power in a remote area of Bangladesh. In this investigation, some of the crucial cases will be examined, which are the optimum turbine placement with the aid of fluid flow simulation using the flow parameters, electric power production in a single power unit and hybrid power system unit, and cost analysis of the hybrid power system unit in order to inspect the feasibility of the system.

The purpose of the program was to develop and demonstrate an advanced hydraulic system designed to operate using an Air Force developed, nonflammable fluid, chlorotrifluoroethylene (CTFE), at a maximum operating pressure of 8000 psi. A total quantity of 600 gallons of CTFE base stock was manufactured for this program by Halocarbon Products and blended with a lubricity additive and a corrosion inhibitor by the Air Force Materials Laboratory. A major portion of an advanced aircraft flight control system was duplicated using flightweight, flightworthy hydraulic components developed by twenty four equipment suppliers contracted to support the program. In addition to the high pressure and new fluid, the program integrated several advanced concepts which reduce power consumption and system heat rejection. The most significant of these is variable system pressure which allows the system to remain at a lower power setting (3000 psi), until a demand occurs. The computer controlled variable pressure pumps then respond with only the amount of increased power needed. Energy savings remains a key issue with this new technology as future tactical aircraft are projected to require three times as much hydraulic power at peak periods than conventional aircraft. The increased system pressure serves to reduce component size to accommodate thinner wings and offset the increased weight of CTFE fluid.

Several hundred megajoules of energy lasting for several seconds are required for magnetic fusion experiments. Such high energy can be stored as inertial energy in an alternator which is brought up to speed slowly. The alternator is then discharged through a thyristor converter to magnets which produce sustain the plasma. A major portion of the inertial stored energy, for reversed field pinch experiments in Los Alamos, will be dissipated in charging the magnetizing coil to produce the plasma. The plasma is then sustained, during the flat-top period, by energizing the magnetizing coil in the reverse direction. To hold the plasma current constant at the required level, the output voltage of the converter must be held at a prescribed level by controlling the firing angle of the thyristors. The paper discusses the possibility of using the same converter for both the magnetizing and the flat-top periods. It also analyzes the electrical requirements that will be imposed on the alternator and the converter.

This report documents the historical and predicted maintenance experience for the DD-963 Class 60/400 Hz static frequency conversion and distribution system, SWAB groups 314-4, 324-1, and 324-4. It presents an analysis of the existing maintenance policy and the maintenance problems encountered and recommends specific actions and maintenance policy modifications to improve equipment availability, reliability, and maintainability. (Author)

Analysis and simulations were performed to provide recommendations on how toimprove the cost-effectiveness of the operation of remote hybrid power systems supportingvarious Alaskan National Distress System (NDS) communications sites. The studycharacterizes the loads and power sources at two NDS sites. Basic lead-acid battery theory isapplied to produce a mathematical model to simulate the normal operation of the hybrid powersystem. Data from 2001 is analyzed to account for the effect of solar energy on the model.Results from the simulations indicate that a cost savings is realizable through improved hybridcontroller settings.

The first-phase effort concentrated on defining the minimum basic functions that the retrodirective array must perform, identifying circuits that are capable of satisfying the basic functions, and looking at some of the error sources in the system and how they affect accuracy. The initial effort also examined three methods for generating torques for mechanical antenna control, performed a rough analysis of the flexible body characteristics of the solar collector, and defined a control system configuration for mechanical pointing control of the array.

A commercial approach to the design and fabrication of an economical space power system is presented. Cost reductions are projected through the conceptual design of a 2 kW space power system built with the capability for having serviceability. The approach to system costing that is used takes into account both the constraints of operation in space and commercial production engineering approaches. The cost of this power system reflects a variety of cost/benefit tradeoffs that would reduce system cost as a function of system reliability requirements, complexity, and the impact of rigid specifications. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance cost estimates are detailed.

The goal of this research project was to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom. The approach consists of four steps: (1) developing analytical tools (models and computer programs); (2) conducting parameterization (what if?) studies; (3) predicting the global space station EMI environment; and (4) providing a basis for modification of EMI standards.

The goal of this research project was to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom. The approach consists of four steps: (1) developing analytical tools (models and computer programs); (2) conducting parameterization (what if?) studies; (3) predicting the global space station EMI environment; and (4) providing a basis for modification of EMI standards.

Steady state analysis of Brayton space power system

The ability is examined of the SSF baselined EPS to transition to operate at a greater system capacity beyond the SSF Permanent Manned Capability PMC) milestone. Specifically, a status of a current analysis is discussed concerning additions, modifications, changeout, or combination thereof of baseline EPS hardware and/or software needed to accomplish the power generation, distribution, operation, and use needed to meet evolving SSF mission objectives. This discussion results in several EPS architectural options that facilitate the addition or substitution of new technologies.

The Environment Power System Analysis Tool (EPSAT) is being developed to provide space power system design engineers with an analysis tool for determining system performance of power systems in both naturally occurring and self-induced environments. The program is producing an easy to use computer aided engineering (CAE) tool general enough to provide a vehicle for technology transfer from space scientists and engineers to power system design engineers. The results of the project after two years of a three year development program are given. The EPSAT approach separates the CAE tool into three distinct functional units: a modern user interface to present information, a data dictionary interpreter to coordinate analysis; and a data base for storing system designs and results of analysis.

Transmission Line Book

An open cycle gas turbine numerical modelling code suitable for thermodynamic performance analysis (i.e. thermal efficiency, specific fuel consumption, cycle state points, working fluid flowrates etc.) of automotive and aircraft powerplant applications has been generated at the NASA Lewis Research Center's Power Technology Division. The use this code can be made available to automotive gas turbine preliminary design efforts, either in its present version, or, assuming that resources can be obtained to incorporate empirical models for component weight and packaging volume, in later version that includes the weight-volume estimator feature. The paper contains a brief discussion of the capabilities of the presently operational version of the code, including a listing of input and output parameters and actual sample output listings.

Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.

Studies were conducted to develop appropriate space shuttle electrical power distribution and control (EPDC) subsystem simulation models and to apply the computer simulations to systems analysis of the EPDC. A previously developed software program (SYSTID) was adapted for this purpose. The following objectives were attained: (1) significant enhancement of the SYSTID time domain simulation software, (2) generation of functionally useful shuttle EPDC element models, and (3) illustrative simulation results in the analysis of EPDC performance, under the conditions of fault, current pulse injection due to lightning, and circuit protection sizing and reaction times.

Power system configurations and reliability for interplanetary missions to Mercury, Venus, Mars, and Jupiter

This paper studies the performance of partial-Rake (PRake) receivers in impulse-radio ultrawideband wireless networks when an energy-efficient power control scheme is adopted. Due to the large bandwidth of the system, the multipath channel is assumed to be frequency-selective. By using noncooperative game-theoretic models and large system analysis, explicit expressions are derived in terms of network parameters to measure the effects of self- and multiple-access interference at a receiving access point. Performance of the PRake is compared in terms of achieved utilities and loss to that of the all-Rake receiver.

n this paper, a detailed dynamic model and simulation of a solar cell/wind turbine/fuel cell hybrid power system is Developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the nuclear energy and thermal power, the renewable energy is inexhaustible and has non-pollution Characteristics. Here Ultra-capacitors are used in power applications requiring short duration peak power. The voltage variation at the output is found to be within the acceptable range. The output fluctuations of the wind turbine varying with wind speed and the solar cell varying with both environmental temperature and sun radiation are reduced using a fuel cell. Therefore, this system can tolerate the rapid changes in load and environmental conditions, and suppress the effects of these fluctuations on the equipment side voltage. The proposed system can be used for off-grid power generation in non interconnected areas or remote isolated communities. Modeling and simulations are conducted using MATLAB/Simulink software packages to verify the effectiveness of the proposed system. The results show that the proposed hybrid power system can tolerate the rapid changes in natural conditions and suppress the effects of these fluctuations on the voltage within the acceptable range.

This paper studies bifurcations in a three node power system when excitation limits are considered. This is done by approximating the limiter by a smooth function to facilitate bifurcation analysis. Spectacular qualitative changes in the system behavior induced by the limiter are illustrated by two case studies. Period doubling bifurcations and multiple attractors are shown to result due to the limiter. Detailed numerical simulations are presented to verify the results and illustrate the nature of the attractors and solutions involved.

This research addresses the problem of temperature fluctuations affecting the efficiency of solar panels. A cooling system has been developed using a Peltier and a combination of air- and water-cooling methods. The air-cooling system involves placing a Peltier coated with a heatsink under the solar panel, while the water-cooling system uses pumped water on the panel's surface. The study aims to design a solar panel cooling system to reduce temperature and power losses and compare its output to standard solar panels. The system includes a Peltier, DC fan, and heatsink. Results indicate that the air-cooling system reduced temperature losses on the bottom milk of solar panels by 14.5%. However, the surface of solar panels showed no reduction in temperature losses. Additionally, solar panels with cooling systems were able to reduce power losses by 4% compared to standard solar panels. This research suggests that the use of an air-cooling system utilizing Peltier as the cooling medium could be a potential solution to reduce temperature losses and power losses on solar panels.

This paper is focused at providing a solution to optimal power flow problem in power systems by using soft computing approaches. The proposed approach finds the optimal setting of OPF control variables which include generator active output, generator bus voltages, transformer tap-setting and shunt devices with the objective function of minimizing the fuel cost.   Soft computing optimization methods have been implemented based on genetic algorithm and particle swarm optimization. The proposed soft computing techniques are modelled to be flexible for implementation to any power systems with the given system line,    bus    data,    generator fuel    cost parameter and forecasted load demand. Proposed soft computing optimization techniques have been analyzed and tested on the standard benchmark IEEE 30-bus system. Results obtained after applying both optimization techniques on American Electric IEEE 30-bus system with the same control variable maximum & minimum limits and system data have been compared and analyzed.   Proposed methods efficiently optimize and solve the optimal power flow problem with high efficiency and wide flexibility for implementation and analysis on different power system networks.

This paper is focused at providing a solution to optimal power flow problem in power systems by using soft computing approaches. The proposed approach finds the optimal setting of OPF control variables which include generator active output, generator bus voltages, transformer tap-setting and shunt devices with the objective function of minimizing the fuel cost.   Soft computing optimization methods have been implemented based on genetic algorithm and particle swarm optimization. The proposed soft computing techniques are modelled to be flexible for implementation to any power systems with the given system line,    bus    data,    generator fuel    cost parameter and forecasted load demand. Proposed soft computing optimization techniques have been analyzed and tested on the standard benchmark IEEE 30-bus system. Results obtained after applying both optimization techniques on American Electric IEEE 30-bus system with the same control variable maximum & minimum limits and system data have been compared and analyzed.   Proposed methods efficiently optimize and solve the optimal power flow problem with high efficiency and wide flexibility for implementation and analysis on different power system networks.

A CRITICAL ANALYSIS OF TRANSIENT STABILITY OF ELECTRICAL POWER SYSTEM A CASE STUDY OF NIGERIAN 330 KV POWER SYSTEM

This research introduces the analysis and design of Class E-LCCL for capacitive power transfer (CPT) system. The CPT Class-E LCCL system is able to operate at high-frequency with decreased capacitance plate size and at reduced power losses by minimising switching losses. Additionally, the design of a CPT Class-E LCCL power amplifier is less complicated, since it is usually lighter and smaller with comparative intolerance to different circuit variants; hence, enabling the possibility of miniaturising the system. In this work, the capability of the CPT Class-E LCCL CPT system powered by 24 V DC supply voltage while operating at 1 MHz was analysed via experimental works and extensive simulation. Lastly, a CPT Class-E LCCL system prototype was built, generating 10 W output power via a 0.1 cm air gap at a near-perfect efficiency level of 96.68%. These findings could be beneficial for household apparatus, medical implants, and charging consumer electronics.

THIS COMPARATIVE ANALYSIS INVESTIGATED MOONLIGHTING, MINIMUM ADEQUATE FAMILY INCOME, TEACHERS' SALARIES AS AGAINST THOSE IN OTHER OCCUPATIONS, AND POTENTIAL EARNING POWER. THE AVERAGE ANNUAL INCOME OF ALL TEACHERS IN THE UNITED STATES DURING 1966-67 WAS $6,820, BELOW THAT OF MOST INDUSTRIAL, TECHNICAL, AND PROFESSIONAL EMPLOYEES. IN THE 50 LARGEST CITIES IT WAS $8,024, WITH SAN FRANCISCO ($10,033), LOS ANGELES ($9,078), AND NEW YORK ($8,900) LEADING THE OTHERS. HOWEVER, A COMPARISON OF THESE SALARIES WITH THE MINIMUM INCOME NEEDED BY FAMILIES SHOWED ONLY A SMALL SURPLUS. THUS, THE HIGH INCIDENCE OF MOONLIGHTING AMONG TEACHERS CAN BE ATTRIBUTED TO A DESIRE FOR FINANCIAL SECURITY AND EARNINGS COMPARABLE TO THOSE WITH THE SAME OR EVEN LESS EDUCATION. STATISTICS FOR BEGINNING TEACHERS AND A DETAILED BREAKDOWN OF THE TEACHER POPULATIONS IN THE VARIOUS SCHOOL SYSTEMS (EXPERIENCE, AVERAGE SALARY, PERCENT AT MAXIUMUM SALARY, SUBSTITUTES) ARE ALSO PROVIDED. THIS PUBLICATION IS ALSO AVAILABLE FROM THE AMERICAN FEDERATION OF TEACHERS, 716 NORTH RUSH STREET, CHICAGO, ILLINOIS 60611, FOR $1.00. (LC)

Modern wind turbine technology has been a great improvement over the past few decades, leading to large scale wind power penetration. The increasing penetration of wind power resulted in emphasizing the importance of reliable and stable operation of power systems, especially in an isolated small-scale power system. This paper describes the impact of full-load converter interfaced wind generators on power system oscillations. Eigenvalue analysis and participation factors are carried out under variant wind power penetration levels to investigate the small signal stability of the isolated small-scale power system in Penghu Island. 

The TOPAZ-II Ya-21U is one of six Russian made space nuclear power systems which is based on theomionic power conversion. The U.S. is presently analyzing TOPAZ-II to determine the reliability and feasibility of using this system. A structural analysis test was conducted on the TOPAZ unit in May 1993 to provide data from which modal parameters could be identified. This test showed the fundamental frequency to be 10.5 Hz, yet the test results that the Russians conducted identified a fundamental frequency of 5 Hz. Another finite element model was created incorporating new developments in TOPAZ-II and modifications to the finite element model to better simulate the mass properties of the TOPAZ-II2. A second structural analysis test was conducted on the TOPAZ unit 06-09 September 1994. This thesis focuses on the random vibration analysis of the TOPAZ-II Ya-2lU utilizing the most recent test results and the Master Series (updated version) I-DEAS software. The modal respose of the model and simulated random vibration tests were within 8.33%. This model is a feasible tool which can be used to analyze the TOPAZ unit without testing the unit to fatigue. (AN)

A computer program to analyze power systems having any number of shafts up to a maximum of five is presented. On each shaft there can be as many as five compressors and five turbines, along with any specified number of intervening intercoolers and reheaters. A recuperator can be included. Turbine coolant flow can be accounted for. Any fuel consisting entirely of hydrogen and/or carbon can be used. The program is valid for maximum temperatures up to about 2000 K (3600 R). The system description, the analysis method, a detailed explanation of program input and output including an illustrative example, a dictionary of program variables, and the program listing are explained.

A standardized data base is described which consists of a space shuttle electrical equipment list, activity blocks defining electrical equipment utilization, and activity-block time lines for specific mission analyses. Information is presented to facilitate utilization of the data base, to provide the basis for the electrical equipment utilization to enable interpretation of analyses based on the data contained herein.

Safety, reliability and quality assurance design analysis results are presented as well as design requirements recommended for implementation in the PEP design.

In a large, interconnected power system, contingency analysis is a useful tool for pinpointing the potential consequences of post-event scenarios on the system's safety. In this work, the Newton-Raphson technique is applied to every single outage of a transmission line to compute the load flows. For the static security classification of the power system, the line voltage stability performance index (LVSI) is used. There are three levels of static security of power system namely: non-critical (the least severe), semi-critically insecure (the next lowest severe), and critical (the next highest severe). The various data mining techniques such as decision trees, bagging-based ensemble methods, and boosting-based ensemble methods were applied to assess the severity of the line under various loading and contingency conditions. Test systems based on the IEEE 30 bus system were used with the proposed machine learning classifiers. The experimental results proved that bagging based ensemble method provided better accuracy compared to the decision tree and the AdaBoost ensemble method for predicting the power system security assessment. The bagging-based ensemble method has a predictive accuracy of 85% and an AUC of 0.94.

Several voltage stability indices (VSIs) have been developed to assess the potential for voltage collapse. However, certain indexes are computationally costly. Meanwhile, some have been noted to underperform across various conditions. This work proposes a novel line index called the super voltage stability index (SVSI) to calculate the system's voltage stability margin (VSM). The suggested approach is based on the transmission system's two bus systems. The reactive power loss and N-1 contingency conditions to voltage sensitivity is a unique calculation approach used in this study to identify voltage instability. Day to day, the demand for electric power is being increased due to incessant increments in technology and population growth. Therefore, the power system networks are under pressure. The operational conditions of transmission system networks are affected at this point, which may result in voltage collapse. Regular monitoring of power supply is essential to avert voltage collapse. The effectiveness of the suggested index has been assessed using the IEEE 5 and 30-bus systems across diverse operating scenarios, including variations in active and reactive power loading as well as single line losses. The findings indicate that SVSI provides a more reliable indication of the proximity to voltage collapse when compared to conventional line VSIs.

The goal is to analyze the potential effects of electromagnetic interference (EMI) originating from power system processing and transmission components for Space Station Freedom.The approach consists of four steps: (1) develop analytical tools (models and computer programs); (2) conduct parameterization studies; (3) predict the global space station EMI environment; and (4) provide a basis for modification of EMI standards.

No Description

User power, duration, and orbit requirements, which were the prime factors influencing power extension package (PEP) design, are discussed. A representative configuration of the PEP concept is presented and the major elements of the system are described as well as the PEP-to-Orbiter and remote manipulator interface provisions.

Rocketdyne plans to generate a system level specification for the Space Station Electric Power System (EPS) in order to facilitate the usage, accountability, and tracking of overall system level requirements. The origins and status of the verification planning effort are traced and an overview of the Space Station program interactions are provided. The work package level interfaces between the EPS and the other Space Station work packages are outlined. A trade study was performed to determine the peaking split between PV and SD, and specifically to compare the inherent total peaking capability with proportionally shared peaking. In order to determine EPS cost drivers for the previous submittal of DRO2, the life cycle cost (LCC) model was run to identify the more significant costs and the factors contributing to them.