Showing papers on "Base load power plant published in 1991"

Micro-hydro Power

Abstract: This guide is specifically addressed to the practical needs of development workers. An overview of micro-hydro is given, and preliminary studies are discussed. Hydrology and site surveys are considered and civil works, penstocks, turbines, governing, drive systems, electrical power, basic economics, commissioning and testing, and operation and maintenance are reviewed in detail. (U.K.).

The Brazilian Power System and the challenge of the Amazon transmission

Abstract: The Brazilian energy resources to be exploited in the near future are located in the Northern region (Amazon basin), where there is a great hydroelectric potential. Major power markets on the other hand are expected to be in the southeastern and northeastern regions. The distances between these Amazon hydro power plants and the load centers range from 2000 to 2800 km. Therefore, a great challenge will have to be faced in the future, namely the transmission of large amounts of energy from very remote sources. The main aspects of the Brazilian Power System and the factors which are being taken into consideration in the definition of the main characteristics of these transmission lines are presented. >

Towards a more comprehensive approach to hydro-thermal power system scheduling by Lagrangian relaxation

Abstract: It has been shown that a practically sized hydro-thermal power system, such as the Scottish system can be modelled comprehensively, and the associated short-term scheduling problem solved within reasonable time-scales, using Lagrangian relaxation techniques. This method allows the hydro-thermal scheduling problem to be split into the separate scheduling of individual thermal units and hydro-system river valleys, co-ordination between these sub-problems being achieved by iteratively updating a set of numbers known as Lagrange multipliers, until the optimum is found. >

Future trends in space power technology

Abstract: The status of the US Air Force Space Power Research and Development Program is summarized. Generic issues and requirements affecting the strategic planning of space power advances for the 1990s and beyond are described. The major thrusts of the Air Fore part of the Strategic Defense Initiative Office Space Power Program are highlighted, with emphasis on the ongoing advanced component technology development program. The status of these component technologies in the areas of power sources, energy storage, power management and distribution, and thermal management is described. Technology projections for the full range of envisioned technology options for the foregoing are used as the basis for a series of point designs for deriving the subsystem- and system-level benefits of the technologies. The primary focus is on baseload (CW) power systems operating in the range from 100 W for small satellites to 50 kW for potential large surveillance satellites. The secondary focus is on large, multimegawatt pulsed power systems and related components for potential applications such as directed energy. Potential 'trump card' technologies related to energy conversion, storage, power electronics, and thermal management are identified. >

Emergency control of power system frequency using flywheel energy injection

Abstract: The automatic disconnection of generating plant under fault conditions presents special problems in isolated small to medium sized power systems. To give an insight into this specific area of power system dynamics, a relatively simple but sufficiently accurate power system model is proposed, to examine the response of power system frequency and demand to an unscheduled generation outage. Using results obtained from this investigation, it is proposed to utilise a flywheel energy storage and retrieval scheme of modest capacity for reduction of load curtailment and replacement of conventional spinning reserve-thus contributing to a reduction of the most significant costs associated with unscheduled power system outages. >

Combined power supply for main and stand-by power

Abstract: A power supply includes a main power supply section having power dissipating components therein and a stand-by power supply section. When the main power supply section is off, the stand-by power supply section uses the power dissipating components in the main power supply section to dissipate waste power. When the main power supply section is on, power from a secondary power supply driven by the output from the main power supply section is used to drive the stand-by power supply section thereby reducing any power dissipating requirements of the stand-by power supply section.

Power source device for internal reformed type fuel cell

Abstract: PURPOSE:To provide a power source device capable of stably coping with a sudden fluctuation of the consumed power of an external load and usable without any problem in a power source device for internal reformed type fuel cell having a control means for controlling the fuel feed quantity to the fuel cell to increase the fuel feed quantity as the output power of the fuel cell is larger on the basis of the information of a detecting means for detecting the output power. CONSTITUTION:A pseudo load means 7 for consuming the output power of a fuel cell D is provided. A control means 6 controls the electrification to the pseudo load means 7 in such a manner that the output power of the fuel cell D is an output power in which a set value is added to the power consumed by an external load 4, and also, when the power consumed by the external load 4 shows a tendency to increase, it controls the electrification to the pseudo load means 7 to reduce the electrification to the pseudo load means 7 by the portion corresponding to the increased portion.

Electrical power industry; today and tomorrow

Abstract: The author presents the present status of power industry emphasizing on distribution, transmission, and generation. Presents the possible future expansions and developments in these areas. Emphasis is given on deregulation and automization of power industry, which would lead to a saving of 50% fuel cost, would improve the efficiency of overall power industry, and ultimately would result in a highly reliable service to the customer and surprisingly at reduce cost.

Economic efficiency, independent power producers and wheeling

Abstract: Traditionally, electric utilities have sought to decrease the cost of production by such means as merit order running of machines, by improving equipment efficiency, by fuel mix, by interconnection and exchange of cheap energy, and by unit participation and firm purchase and sale contracts for long term savings. The author discusses some of the costs that, under the anticipated US modus operandi, must be integrated into the planning, process while meeting the new challenges. The costs are those relating to third-parties, costs of transmission constraints, and costs of wheeling. The opinion is ventured that much of the efficiency improvement anticipated during the debate has already been achieved by conscientious utility managements. >

Control valves limit turbine temperature swings

Abstract: This paper reports that daily cycling of large generating units that were designed for base load now is an economic necessity for many utilities. And repeated temperature changes common to cycling can result in thermal stress which may shorten the life of turbines and boiler parts. The problem was recognized years ago in supercritical and subcritical once-through steam generators that were designed for minimum loads of 30% to 50%. Redesign solutions were developed, with varying degrees of success, to permit frequent cycling to much lower loads. One goal had been to reduce turbine temperature change during wide load swings. As for drum-boiler units, the jury is still out. Some were redesigned to hold boiler and turbine temperatures relatively constant. Other power plants resorted to sliding-pressure operation to relieve the problem in turbine-generators only, but relatively lengthy ramp times to reach full load still persist.

Correction to 'Optimization of multiplant cogeneration system operation including electric and steam networks' (May 91 484-490)

Abstract: A missing page for the above-titled paper (see ibid., vol.6, no.2, p.484-90, May 1991) is given. >

Highly Efficient Automated Control for an MGR Gas Turbine Power Plant

Abstract: A control system design for the Modular High Temperature Gas-Cooled Reactor Gas Turbine power plant (MGR-GT) is presented. The control system is designed to provide full-scale automated control functions for power output regulation and plant protection in accordance with utility requirements for modular nuclear power plants. Control of the plant power output is based on a unique integration of inventory control and bypass control, which not only enables required load following capabilities but also offers 45% electric generating efficiency over the power ranges from 100% to 50% of the rated level. The reactor power is controlled based on the strategy of maintaining constant core outlet temperature. This approach minimizes the occurrence of thermal transients and temperature redistribution in the core during reactor power changes. In addition, the control system also provides emergency protective control to protect the plant components and to mitigate the likelihood of bounding safety events in case of severe accidents. The operation of the control system is automated by controllers implemented based on the state-space feedback control methodology. A spectrum of transients in both normal and far-off normal conditions has been simulated to evaluate the operability of the plant. The simulation results for a few selected events will be described. The design demonstrates that the MGR-GT is a highly efficient and robust controllable power plant.Copyright © 1991 by ASME

Flexibility for CGCC power generation; LPM energy storage

Abstract: Energy storage systems have long been used to increase the utilization of capital-intensive power generating assets. Conventional energy storage technologies - such as pumped hydroelectric, compressed air, and batteries - take excess electric power from baseload generating units, store it, and deliver power during peak demand periods. While these technologies share a common objective, they each have their own characteristics and in fact are rather different one from another. The choice of energy storage technology is obviously dependent on many factors, including size, system characteristics, lead time, topographic and environmental considerations - and of course, efficiency and cost. This paper describes a technology which provides energy storage to complement a Coal Gasification Combined-Cycle electric power facility. The concept is called the Liquid Phase Methanol (LPM) process which co-produces methanol along with electric power. Because of the synergy of the LPM process with the CGCC process there are unusual efficiency, cost and flexibility benefits realized with this type of energy storage as compared to conventional systems.

Lighter fuel-the gas turbine comes of age

Abstract: Some profound changes are overcoming the technology of electricity generation. A combination of environmental, economic and technical factors is increasingly leading generators to favour the adoption of gas-turbine-based plant. The author discusses the reasons for the increased use of gas turbines and discusses their operating principles. The use of turbine exhaust gases for steam generation of direct heating (cogeneration plants) is also discussed as is the application of gas turbines to base load and gasification plants. Future prospects are mentioned. >

New US nuclear plants: one scenario

Abstract: It is pointed out that the obstacles to new nuclear power plants in the US are many and well-known, but that there are some signs pointing toward at least a partial removal of the obstacles. Electric load continues to grow above forecast rates in many regions. New designs are being developed for smaller, simpler plants with improved safety features, shorter construction schedules, and lower capital requirements, resulting in less financial exposure to the owner. Also, legislative and regulatory initiatives are underway to reduce the uncertainty in the licensing environment. The author reviews these hopeful indications and postulates one plausible scenario for the near-term revival of domestic nuclear plant construction in the US for base load electric generation. According to this scenario, during an energy supply crisis, a group of electric utilities, with favorable nuclear experience, form a consortium with other industry participants, such as suppliers, architect engineers, and constructors, to develop and implement a project which would include several standardized ALWR (advanced light water reactor) units, with each utility owning a portion of each unit. >

V84. 2 gas turbine package for U. S. utility service

Abstract: This paper discusses the basis of the Turbo Power and Marine's V84.2 package design, including a review of the design philosophy and commonality with both future models and other TPM products. Also discussed are the key features of the design, utilizing Reliability, Availability, and Maintainability (RAM) principles and concepts. Control, maintenance accessibility, and flexibility through pre-engineered options are also discussed. It further describes the broad spectrum of V84.2 use in peaking, and base load applications.

Investigation on the treatment of generating unit outages in probabilistic production simulation

Abstract: The authors report the results of an investigation on several treatments of generating unit random outages in probabilistic production simulation. An electric utility system with a mix of nuclear, coal, and gas-fired generating units and a peak load of about 5000 MW was used in the investigation. The authors also describe the treatment of the unit random outages, the utility system, simulation results and conclusions. >

Estimation of small and large-scale industrial power plants operation and their impact on supply reliability assessment

Abstract: When estimating industrial power plant operation and its impact on power supply reliability, an assessment is necessary. In view of this, the equivalent assisting unit approach is presented and described. The equivalent assisting unit approach allows the presentation of a tie line as an equivalent assisting power plant with a capacity equal to the tie line capacity and an availability equal to the tie line supply availability. The theoretical approaches and models presented allow qualitative and quantitative estimation of the operation of industrial power plants and their impact on supply reliability assessment. >

Importance Of Generation Scheduling Of Thermal Units For Economic Operation Of Power Systems

Abstract: The demand for electrical power is growing rapidly due to industrialisation and the utilities are not in a position to plan their generation capacity additions suitably to meet this growing demand for power. This has resulted in a large gap between generation and demand. In this context, economical operation of the system, so as to utilise the capacities optimally become very important. This can be achieved by suitably scheduling the thermal generating units and committing them appropriately, for a projected load demand on the system, arrived at, using short term load forecasting techniques.

Power quality of rural distribution system

Abstract: The authors present the results of a detailed power supply quality survey of 23 small rural industries sponsored by the Canadian Electrical Association. They summarize the major power quality problems experienced at the various rural sites. The results of the survey will provide a knowledge base on rural power quality and the possible origins of power supply anomalies which are necessary for mitigating actions by the electric utilities and their rural customers. One of the major problems identified during the power quality site surveys was poor voltage regulation of the distribution feeders. The high steady-state voltage levels at some sites significantly reduced the life expectancy of incandescent lamps. The poor voltage regulation, resulting in high RMs voltage levels, usually occurred during the early parts of the morning when the utility's transmission and distribution systems were lightly loaded. >

New approach to kVAr-compensation in a 132 kV system using measured power factor

Abstract: The special load conditions of a 132/11 kV cable system in a subtropical country are described, which is characterized by great variation of the load pattern. Due to the unique load mixture consisting mainly of motor load during peak load and lighting load during low load conditions, the reactive power compensation is becoming a severe problem to be considered for planning and operation purposes. The reactive power compensation scheme is based on the active and reactive power measured at those substations feeding the 132 kV system from the national grid and from the power stations. The proposed method utilizes the existing 132 kV reactors and requires installation of additional capacitors to be installed on the 11 kV side. The control scheme automatically adjusts the reactive power supplying the 132 kV system in a narrow bandwidth around p.f.=0.98. >