New Publications are available for Gas-turbine power stations and plants
http://dl-live.theiet.org
New Publications are available now online for this publication.
Please follow the links to view the publication.Techno-economic assessment of energy storage systems for enabling projected increase of renewables onto electrical power grids
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0135
Hydrogen is seen by many industry leaders as an energy vector that has the potential to provide essential energy stores required to facilitate the wide spread connection of renewable energy inputs. The techno economic assessment of using hydrogen as an energy storage mechanism, where water (H2O) is split into H2 and Oxygen (O2) when excess renewable energy is available through the use of electrolysis will be examined. H2 will be stored and O2 vented. Fuel Cells (FC), Internal Combustion Engines (ICE) or gas turbines would then be used to convert stored H2 to generate and supply electrical infrastructure with electrical power when demand exceeds renewable supply. Presented in this paper are the findings of a techno economic assessment of existing energy storage systems in comparison to Hydrogen (H2) energy storage technologies. (6 pages)Analysis of a combined radial-axial magnetic bearing for a high-speed drive system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0091
High-speed and high-power-density drives are attracting much interest in today's industry, e.g. for applications with mesoscale gas turbine generator systems or turbocompressors for fuel cells. In all high-speed machinery the bearing is a key component. Therefore, this paper presents the analysis of an active magnetic bearing suitable for a permanent magnet machine, being part of a high-speed electrical drive system. The focus is on the detailed analysis of the magnetic forces, the coupling between the different axes and the verification of the theoretical considerations by means of 3D-FEM simulations. The analysis of the bearing forces is needed to implement the position control to the prototype of the bearing system, which already has been built. (6 pages)Evaluation of the dynamic interactions between aircraft gas turbine engine and electrical system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080606
With the growing demand for increased electrical power offtake from aircraft engines (especially in future more-electric aircraft with bleedless engine designs), it is increasingly important to understand the relationship that exists between the operation of the engine and the behaviour of the aircraft electrical power distribution system. Indeed simplifying either system neglects key aspects of whole system dynamics. This paper discusses potential interactions that could take place, with both conventional and more-electric engine designs, highlighting the risks as well as opportunities for improved overall system performance. The paper then discusses the integration of high fidelity models of an engine and an aircraft electrical power distribution system for the purposes of investigating the holistic system behaviour. Preliminary simulation results are presented to demonstrate the modelling and simulation capability as well as illustrating the opportunities for further research.Distributed energy supplying based on energy pool and the interface to common power system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061884
After analyzing typical structure of distributed energy supplying system, a new idea of distributed energy supplying system based on "energy pool" is proposed in this paper, whose energy exchanging process is also discussed. The new idea lays stress on the harmonious control of energy stored in the energy-storage device and that exchanged between the distributed system and common power system. Since the power balance within the distributed system is realized in a way with the help of distributed regulating power source such as micro-gas turbine, the demand for large capacity energy-storage device is reduced. Characters those an ideal interface for a distributed system connecting into common power system should have are summarized and HVDC-Light technology based on voltage source converter are recommended to be used for realizing the interface. (5 pages)Simultaneous control of voltage and power of micro-turbine in distribution network
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051253
Distributed generation (DG) is expected to play an increasingly significant role in power generation in coming years. In Iran, more attention is recently paid to the micro-turbines (MTs), since 20% of the world's gas resources are believed to exist in Iran. A MT unit consists of a gas turbine engine, a permanent magnet generator, a 3-phase AC/DC rectifier and a DC/AC power inverter. In this paper this combination has been modeled by PSCAD/EMTDC. It is shown that the well-known voltage control strategy of MT can result in operational problems for MT and distribution system. A new method is presented in this paper, to overcome these problems. Simulation results show that the proposed control strategy can limit the active and reactive power flow of the MT and can limit the short circuit capacity of the system too. (5 pages)Dynamic simulation of microturbine generation system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051282
This paper describes the development of a dynamic model of a microturbine system. The microturbine unit consists of a compressor and a turbine connected on a single shaft to a high-speed generator. Moreover there is a combustion chamber, a recuperator and a gas/water heat exchanger. A control system regulates the speed, temperature and the electric power. To control the frequency, voltage and current of the outgoing power, the microturbine uses power electronics. In this paper, the functional theory of each component and its modelling in Matlab/Simulink environment is described. (5 pages)Combined use of simulation and test site electrical networks for assessing and evaluating distributed generation possibilities and performances
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051252
The paper presents the results of on-going activities related to National and International Research Projects aimed at analyzing the perspectives for distributed generation (DG) in regional and local electrical systems. An overview of possible distribution networks for subsequent analysis of DG impact on their operation is reported with reference to three typologies: rural, urban and a test facility network. Results concerning static and dynamic issues related to modeling and simulation of a micro-turbine generator included in the test facility network are reported. (6 pages)Control of a variable speed, fault-tolerant permanent magnet generator
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020166
The control of power from a variable speed permanent magnet generator on the low pressure shaft of a gas turbine aero-engine is discussed. The application requires a fault tolerant generator (a high impedance design) to limit the fault current to the full load current at all speeds. The maximum power generation is constant over the whole speed range of the generator. The proposed system seeks to minimise the current rating of the converter and generator. The converter voltage is set at the minimum speed and then held constant as the speed increases. At higher speeds, reactive power is circulated between the generator and the converter to hold down the converter output voltage. This allows the design of the generator to be changed to increase the EMF, decreasing the current rating. At zero power demand, current still flows between the generator and the converter, except at the very lowest speeds. Under fault conditions the generator terminals must be short-circuited to limit the terminal voltage.Transient analysis of a combined cycle power plant (CCGT) connected directly to the distribution network
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020079
Distribution networks in the UK have been designed in order that electrical power is provided by large scale generating stations via the transmission network. A distribution network typically operates at voltages up to and including 132 kV with the end customers directly connected. Legislations introduced by the present UK government state that 10% of the total UK energy should be provided from renewable sources, and 10GWe of combined heating power (CHP) should be provided by 2010. This will inevitably lead to a large increase in distributed generation in the UK by 2010. Distributed (embedded) generation is defined as that generation connected directly to the distribution network. The gas turbine is used extensively in these new schemes. It is commonly used in CHP schemes where use is made of the waste heat present in the gas turbine exhaust gases for industrial processes or domestic heating. A far more beneficial practice with respect to the distribution network is to utilize the gas turbine in a combined cycle gas turbine (CCGT) plant. This paper presents the results of the transient performance of a CCGT plant when connected to the distribution network (Chilvers (1)).Active filter for a microturbine
http://dl-live.theiet.org/content/conferences/10.1049/cp_20010594
An idea of using an existing device in a given topology to eliminate or lower current harmonics in a microturbine unit is presented. To implement this idea, no hardware changes are required. The benefits for the high-speed generator are tremendous and allow simplification of its design, which is crucial for such systems. The article provides general information about microturbines, a detailed description of the idea and simulation and measurement results.A model of cogeneration plants based on small-size gas turbines
http://dl-live.theiet.org/content/conferences/10.1049/cp_20010847
A dynamic mathematical model of a generic cogeneration plant with a microturbine is described and the corresponding regulating system is realized. The chief aim of this model is the evaluation of the services such a system is able to provide to an interconnected electric network, both in normal operation and in case of wide perturbations, or to an islanded grid in consequence of the separation from the main network. The design of the regulating system takes into account the maximum acceptable power variations, in observance of the limitations the constructor has imposed to the process variables and respecting the requirements of the local thermal loads; the result is a quick and robust regulation, even in case of internal failures. (5 pages)Economic assessment of the installation of natural gas-fuelled microturbines and results of preliminary tests
http://dl-live.theiet.org/content/conferences/10.1049/cp_20010845
The major breakthrough in the gas turbine industry has allowed construction of small size machines that feature electric capacities ranging from 25 to 100 kW (the so called microturbines). A high specific capacity, a low cost and a somewhat significant power efficiency are all properties of these machines associated with low noise, low pollutant emissions and low maintenance requirements. It is for all the above mentioned reasons that the microturbines are expected to have a significant market penetration in the niche of the stand-by (field generators), automotive and stationary power generation. Their design providing parallel, mains and co-gen power generation make them virtually fit the needs of a diversified range of users. This paper is intended to provide a preliminary economic assessment of their application at MV users' (within the Italian power and gas tariffs relevant to noneligible customers) and to report the main results from the tests carried out on a 45 kW machine. (4 pages)Measurement of emissions from offshore combustion-user's requirements
http://dl-live.theiet.org/content/conferences/10.1049/ic_20000399
UK offshore legislation has just been introduced that requires monitoring of pollutants from gas turbines. This has meant a marked change in culture and technology as traditionally there has been a `fuel is free' mentality. Also emissions have rarely been measured. The remote location of offshore platforms means that unique solutions are required, especially regarding any changes in the plant that are necessary to install instrumentation. Accuracy and reliability of the instrumentation is crucial. No solutions are proposed in this paper. The objective is to review the background to the user's requirements in light of the change in culture and the new legislation. A challenge is set to the industry to produce cost effective and accurate monitoring methods. (3 pages)High speed permanent magnet axial flux generator
http://dl-live.theiet.org/content/conferences/10.1049/ic_20000460
The basic principle of an axial-flux high-speed generator relies on high speed power take-off from a small gas turbine engine. The benefits in using the gas turbine engine include compact size (attractive power to weight ratio), continuous lean combustion and hence low emissions, as well as multi-fuel capability and high efficiency when used with a heat exchanger. The low parts count of the gas turbine is also attractive since it allows lower manufacturing cost. In the past, the power take-off from the gas turbine engine through a gear box invariably added to weight, size, cost, and sometimes to reliability problems. The author describes how the high-speed axial-flux permanent magnet generator was designed to dispense with the gear box being directly driven by the gas turbine engine, hence the name turbogenerator. (3 pages)Electrical design requirements
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990660
The typical single line diagram of a 40-50 MW open cycle GTG plant is indicated. The plant would typically incorporate a single aeroderivative gas turbine with no requirement to operate as an island with any adjacent industrial site. The two sections of the electrical system are: the connection to the REC, and the derivation of supplies for electrical auxiliaries. Both electrical system sections are discussed. (6 pages)Gas and the current generation mix in England and Wales
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990747
Since the lifting of the ban on burning gas to generate electricity in the early 1990s, there has been an enormous increase in the amount of electricity produced from gas. At the present time, almost one-third of the UK's total electricity demand is met by gas fired power stations. This paper looks at the recent situation in the competitive mid-merit market and makes some predictions on the likely generation mix serving that part of the market. It goes on to describe the outcome of the review of energy sources for power generation, which Merz and McLellan undertook for Department of Trade and Industry in the early part of 1998. Finally, it examines the current situation with regard to proposed new gas-fired generation projects. (16 pages)Contractual issues for generators arising out of RGTA and RETA
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990746
The growth of gas-fired generation in the UK over has by any standards been extremely rapid. In 1990 gas held a 1% stake in the market which by 1997 had increased to 27%. This market share is due to increase as projects which have received the necessary consents reach completion. This paper examines some of the contractual issues that are likely to arise for generators from the interaction between the proposals emerging from the Review of the Electricity Trading Arrangements and electricity and gas markets in light of the Review of Gas Trading Arrangements. (7 pages)Gas turbine maintenance
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990662
Gas turbine maintenance is a very wide subject that is difficult to cover in any one presentation. This paper aims to provide a brief overview of mid-merit operation and its effect on maintenance and the benefits of performing some sort of proactive maintenance. Changes in customer expectations and turbine technology have meant that manufacturers are having to re-evaluate the way their equipment is supported. This has led to a rapid growth in long-term maintenance contracts and a greater focus on flexible maintenance practices that provide value for money. (4 pages)The physical operation of Transco's national transmission system
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990744
This paper seeks to give an overview of Transco's gas transportation network and examines the physical operation of the National Transmission System (NTS). In addition it also discusses the impact of gas-fired power stations as direct loads connected to the NTS and how their demand portfolio is managed as part of daily balancing. (5 pages)Gas generation in traded energy markets
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990748
In this paper the author moves away from the operational aspects of the transmission systems to the resulting market consequences of the interaction between the gas and electricity systems. The author discusses four areas of interest. Firstly, he looks briefly at the forward price curves for UK gas and electricity. The author then looks at where gas generation fits in the current merit order, relative to other fuels, and then consider where it might fit in the future. The author then develops this theme to talk about how power price exposure might be managed within the gas market in the new world. Finally, the author makes a few observations relating to the interaction between the gas and power markets under RETA and RGTA. (16 pages)From an engineering lead product to a market driven solution: from first generation to third generation gas turbine power generation
http://dl-live.theiet.org/content/conferences/10.1049/ic_19990661
This paper presents an account of how the engineering of the product, the perceptions and the demands of the market and the relationship with the power generation customer have evolved over the last 35 to 40 years. This paper gives an insight into the engineering of gas turbines and how technology has become fundamental to delivering that which the customer deems to be important. (5 pages)Effectiveness of feature extraction in neural network architectures for novelty detection
http://dl-live.theiet.org/content/conferences/10.1049/cp_19991239
This paper examines the performance of seven neural network architectures in classifying and detecting novel events contained within data collected from turbine sensors. Several different multilayer perceptrons were built and trained using backpropagation, conjugate gradient and quasi-Newton training algorithms. In addition, linear networks, radial basis function networks, probabilistic networks and Kohonen self organising feature maps were also built and trained, with the objective of discovering the most appropriate architecture. Because of the large input set involved in practice, feature extraction is examined to reduce the input features, the techniques considered being stepwise linear regression and a genetic algorithm. The results of these experiments have demonstrated an improvement in classification performance for multilayer perceptrons, Kohonen and probabilistic networks, using both genetic algorithms and stepwise linear regression over other architectures considered in this work. In addition, linear regression also performed better than a genetic algorithm for feature extraction. For classification problems involving a clear two class structure we consider a synthesis of stepwise linear regression with any of the architectures listed above to offer demonstrable improvements in performance for important real world tasks.Control room for high-efficiency power plant
http://dl-live.theiet.org/content/conferences/10.1049/cp_19990170
This paper describes the design of the control room for a high-efficiency power plant and addresses the choice of operation mode discussing operation using the screen-based technique as supplement to or substitution for a conventional switchboard; presents the design of the control room on the basis of comfort parameters; discusses methods of arranging the task-oriented areas in the control room in relation to each other; describes the principles of selecting information to the operators on screen images; and finally reports experience from the first two years of operation together with more important lessons learnt from the operators' work in the selected surroundings and with the system. Thus the whole process of creating optimum conditions for the operators has taken human factors into account. The design of the control room and operating media has been completed with respect to complying with the planned high efficiency of the unit.The design of modern air-cooled turbogenerators for gas turbine power stations
http://dl-live.theiet.org/content/conferences/10.1049/cp_19990997
Air-cooled turbogenerator design technology was well established by the 1960s. Since then, opportunities have continually arisen with new materials, particularly for insulation and auxiliaries, and with the development of modern computing methods. Today, sophisticated analytical tools are more commonly used during the design of rotating machines in the areas of: airflow and thermal analysis; electromagnetic analysis; and stress-analysis. These factors, combined with the pressures to reduce costs in the global market, require a radically new approach in the design of modern air-cooled turbogenerators. This paper describes how Brush Electrical Machines Ltd (BEM) are applying the latest computing methods in the design of these machines with particular emphasis on air circuit design, EM analysis, and thermal analysis.Provision of power reserve service from CCGT plant
http://dl-live.theiet.org/content/conferences/10.1049/ic_19980016
Since 1990 the quality of the electricity supply has been managed by NGC, under a portfolio of contracts for ancillary services. The structure and strategy behind these contracts is to facilitate reliable and economic system operation to meet NGC's licence obligations. NGC have argued that it is becoming more and more difficult to meet these obligations since the introduction of CCGT plant. The response capability of connected generating plant becomes particularly critical under lightly loaded system conditions. This is primarily due to the large percentage of plant that is unable or not providing a response under the current contractual arrangements. In an attempt to address the issue, changes have been proposed to the Grid Code that define a minimum level of frequency response capability NGC have also vigorously pursued CCGT plant to comply with their interpretation of connection conditions that apply to system frequency. The concerns have now been escalated to Government level. The President of the Board of Trade has issued, under the terms of the review of Energy Sources for Power Stations, a remit to consider the technical factors related to provision of system stability, frequency control, flexibility of response to demand or supply variations and ancillary security services provided by the use of gas in generation. The paper provides an indication of the generic capabilities of modern CCGT plant in meeting current grid code conditions and providing economic frequency response services. (6 pages)CHP in Newcastle upon Tyne
http://dl-live.theiet.org/content/conferences/10.1049/ic_19980179
The paper covers the development of a combined heat and power scheme, with an associated community heating network, in the centre of the city of Newcastle upon Tyne. The scheme would comprise a gas fired gas turbine driven electricity generator to provide electrical energy to a major hospital complex and the adjacent university. Waste heat from the gas turbine would be used to displace or supplement existing boiler plant in the hospital and university and also in those municipal buildings (including a second university) in the centre of the city connected to the community heating network. (11 pages)Decision support in short term and long term maintenance planning using condition monitoring information
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980060
Improved utilization of condition information in connection with maintenance planning of offshore installations has a potential for significant costs savings. This paper presents approaches for utilization of condition information both in short term and long term maintenance planning. In connection with short term planning for improved coordination of jobs, in long term planning for improved estimation of residual life of systems and equipment. The short term maintenance planning approach uses information from several systems such as condition monitoring, maintenance planning and management systems for equipment and spares. A decision support tool assists the selection of maintenance activities and performs a dynamic grouping of the maintenance activities. The paper does not provide any mathematical formulation of the short term optimization problem, but attempts to identify and briefly discuss important parameters influencing the optimal solution. The long term maintenance planning approach includes the use of condition monitoring data in the evaluation of optimal replacement policy. A stochastic dynamic decision model has been developed using knowledge about the nature of equipment/systems condition. Two examples are discussed, a gas compressor and a gas turbine.Driving outage times down and improving joint integrity using bolt tensioning
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980079
Today's increasing demand for reduction in outage times are leading many turbine OEM's and power utilities to question traditional methods of joint closure to find a faster and more accurate method. The authors detail how they believe that hydraulic tensioning technology will become an integral part of steam and gas turbines and associated critical items to reduce maintenance time, increase availability and give reliable repeatable jointing.TIGER<sup xmlns="http://pub2web.metastore.ingenta.com/ns/">TM</sup>: intelligent continuous monitoring of gas turbines
http://dl-live.theiet.org/content/conferences/10.1049/ic_19971143
Gas turbines are one of the prime providers of power for many modern industrial plants. They are critical for power generation and the critical power provider at many modern chemical and process plants. It is vital that these gas turbines work at optimum efficiency and with high availability. The paper discusses the TIGER gas turbine monitoring system. TIGER is a software system that receives over 600 measurements at once per second intervals directly from the controller of a gas turbine, and using an innovative combination of artificial intelligence techniques, automatically makes an assessment of the condition of the gas turbine, just as the best human expert would. It includes extensive diagnostics to identify the cause of any small deviations or failures, as well as the cause of any major trips. (4 pages)Active magnetic bearing requirements for turbomachinery
http://dl-live.theiet.org/content/conferences/10.1049/ic_19970894
Rolls Royce (RR) have been interested in the application of active magnetic bearings (AMBs) for a number of years and have carried out two demonstrator programmes and a number of design studies. The generic benefits of AMBs to a range of machinery are summarised. The authors discuss the technology demonstrators, the design requirements, robust control, hardware redundancy, digital controller, software design and power supplies for the AMBs. The maximum benefits from this technology will be derived by the integration of AMBs into new machine designs rather than backfits into existing equipment. (9 pages)Eddy-current losses in the permanent magnets of a PM machine
http://dl-live.theiet.org/content/conferences/10.1049/cp_19971054
A gas turbine driven, high-speed, high-efficiency generator system intended for use in series-hybrid vehicles is developed. It consists of a permanent-magnet (PM) generator and a rectifier. The eddy-current loss in the magnets of the high-speed PM generator may be problematic. Therefore, a model of the PM machine including this loss in the magnets due to the time harmonics of the stator currents is introduced and verified. This loss can be represented by magnet loss resistances in the equivalent circuits. It can be decreased by using smaller magnets or by using sinusoidal stator currents.Offshore power generation - limited life expectancy
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960112
The offshore oil industry has been well established on the United Kingdom Continental Shelf for some 20 years. In that time some hundreds of megawatts of gas turbine power generation has been installed on oil and gas production platforms. The size of power generators has gradually increased as has the electrical load on the platforms. As the production declines and new frontier areas are opened up, what further opportunities are there for the power generation industry? This paper looks at how the development of platform power system design has changed over the years and presents one future scenario that may not include any power generation on the platform itself but will use underwater DC power cables from the shore.The ‘success’ of the combined cycle gas turbine
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960125
Over the last 20 years, a new technology for power generation has emerged. The combined cycle gas turbine (CCGT) has been installed in increasing numbers throughout the world. Synthesised from traditional gas and steam turbine technology, the CCGT appears to have been at a sufficiently mature stage of development to take advantage of the worldwide shift towards a more market-driven economic climate. Also of importance has been the availability of large quantities of natural gas, coupled with widespread concern at the environmental effects of traditional technologies. In this short paper, the aim is to re-evaluate the conventional wisdom that the CCGT has become so popular solely due to changed market circumstances and cheap natural gas. It is demonstrated that many political and technological factors have had a part to play, particularly in countries such as the UK, where the CCGT has had a large impact. To do this, the history of the CCGT is analysed from three related perspectives. These examine the technology itself and its attributes, the role of the equipment manufacturers, and the involvement of Governments. The conclusions will hopefully lead to some wider debate about the general view of technological development, how it should be handled and by whom.The high speed axial flux disc generator - unlocking the potential of the automotive gas turbine
http://dl-live.theiet.org/content/conferences/10.1049/ic_19960900
To enable an electric traction vehicle to have acceptable performance and range, a hybrid approach must be adopted whereby electrical power is generated on board by means of a combustion engine and generator in addition to the energy storage device. One approach is to couple a spark ignition or diesel engine to a conventional generator but an alternative solution of a gas turbine driving a high speed generator, denoted a turbogenerator, is considered superior for the following reasons: the power plant has a much lower weight and volume; toxic emissions are much lower due to steady flow combustion in the gas turbine; noise and vibration are reduced; and multifuel capability is inherent with the gas turbine. The most favoured design for the high speed generator is a permanent magnet synchronous machine but this may either have the disc or drum topology. The disc topology offers the following advantages over drum type machines: the magnet containment structure is not in the magnetic circuit; iron hysteresis and eddy currents are eliminated; the rotor has better rotor dynamics characteristics suitable for high speed operation; and the design lends itself to air cooling. (4 pages)Opportunities for advanced sensors for condition monitoring of gas turbines
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960131
The power generation business is a very competitive market for both the original equipment manufacturers as well as the power utilities. A variety of economic and technical forces have produced large industrial gas turbines with ever increasing levels of efficiency, and operators are now being offered combined-cycle gas turbine plant with efficiencies of 57-60%. Simultaneously the operating companies are under continued pressure to minimise operating and maintenance costs. Since fuel costs represent the main part of the running costs, high efficiency units are attractive, providing they can meet the projected reliability and availability targets. To minimise operator risks it is prudent to seriously consider the level of monitoring a unit requires, and whether this should go beyond that normally offered. It is within this context that the role of sensors and the associated opportunities lie. They provide a fuller picture of the operating conditions within the unit, allowing a move towards a condition monitoring based decision making process for both operational and maintenance issues. This paper provides a review of advanced sensoring techniques for monitoring the condition of gas turbines with particular emphasis on those parameters likely to be affected by the design changes found in the newer units. These include: vibration monitoring; performance monitoring; lubrication system monitoring; pyrometry; and continuous emissions monitoring. Techniques under development are also discussed.Scheduling CCGTs in the electricity pool
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960111
This paper presents a review of the scheduling problem of nontraditional generators in England and Wales. It discusses the problems that have been faced, since the privatisation of the industry in England and Wales, by the new tranche of generation which is unable to conform to the classical bidding structure of the original CEGB plant. The more recent capacity comprises combined gas turbines and steam turbines. Such units which may operate as a single unit, or combination of other like units and/or a steam turbine. It is not possible to create a bid pattern for these interlinked modes of operation which fully reflects the cost structure which is represented by the existing three point linear fit. This paper reviews different methodologies that were considered for the scheduling of CCGTs to account for their own unique constraint characteristics and modes of operation. It reports in detail the method that was favoured by a number of the actual CCGT operators, from a technical and economic view point.Development of privatized power industry in Malaysia
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960113
In the last few decades reliable supply of electric power has become a central issue in the development and economic prosperity of any country. There have been far reaching and radical developments taking place in the electric power industry. Among other developments, privatization trends in power generation are having significant implications on the planning and operation of electric utilities. Over the last few years, Malaysia has experienced a rapid economic growth resulting in an ever increasing demand of electricity. This has prompted the Government of Malaysia to invite private power companies to build, own and operate power generation facilities to meet the growing needs of electric power in the country. This paper provides an overview of the development of the privatized power industry in Malaysia and the government efforts to liberalise the electric power sector in order to create an environment of increased competition and efficiency. The paper presents brief history of the private power generation in the country, and provides the information regarding technical, financial and commercial aspects of the power generation projects constructed in the private sector. Finally, the paper presents a case study on the implementation of a private gas turbine power plant project by Powertek, and various technical and operational issues confronted by the owners of the project.Combined cycle gas turbines and clean coal
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960126
Increasing power generation requirements, competition with other fuels, work in regions which were or are industrialised but rich only in coal have forced the production of alternative fuels from coal. Various processes have now been developed to enable the production of clean, relatively simple fuels from coal. This is clean coal technology. Here, the author describes a prototype integrated combined cycle gas turbine power plant to demonstrate that viable clean coal technology can now be designed and constructed with confidence. Identification of a host site for the prototype plant is an action being undertaken at this time. Work continues to advance the state of the technology which is being established to permit the design of a full 400 MWe and larger commercial plants.Energy from waste in the sewage treatment process
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960122
Thames Water consumes over £40m of electricity per year. 70% of this demand is expended on pumping alone, while much of the remainder is needed to aerate sewage as part of the treatment process. The power generated by the waste is worth a further and £8m per annum to Thames Water. Naturally the efficient and economic use of energy is high on the company's agenda. Thames Water and its predecessors have been generating electricity from sewage for half a century. The author briefly outlines the power generation process and the power plant technology used which is based on gas turbines, spark ignition engines, and dual fuel compression engines.Matrix converter application for direct-drive gas turbine generator sets
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960896
A new real-time control strategy for a matrix converter is presented. This has been optimised for use with high speed generators in directly driven gas turbine CHP units. The strategy is based on a microcontroller system with all calculations performed without the need for external, dedicated hardware. The results show that this approach can produce good quality outputs without introducing any limitations to the circuits inherent versatility.Power generation using high efficiency aeroderivative gas turbines
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960128
The introduction of modern, high thrust aero-engines for aircraft propulsion has led to the development of a comparable range of new high power, high efficiency, aeroderivative gas turbines. This is typified by the Rolls-Royce TRENT, the world's most powerful aeroderivative and most efficient gas turbine of any type. The development of these large, efficient aeroderivative gas turbines (GTs) present specific opportunities for use in power generation and combined heat and power plants. This paper outlines the features that distinguish the TRENT aeroderivative GT and its merits in power generation. Consideration is given to the issues that differentiate the aeroderivative GT from industrial design GT plants and specific case studies are discussed which demonstrate the advantage of aeroderivative GTs.Frequency control capability of ABB combined-cycle gas turbine power plants
http://dl-live.theiet.org/content/conferences/10.1049/ic_19950160
Power stations used to support grid frequency must be able to operate in the part-load range so that they can supply the required power reserves. They must also be able to respond quickly within a few seconds after a collapse in grid frequency. Due to the quick reaction time needed, only gas turbines are used for this purpose. Gas turbines have a lower thermal efficiency in their lower part-load range but, if their control systems are properly designed, modern ABB gas turbines-as shown here using the GT 13E2 as an example-can, in conjunction with combined cycle power plants, meet all the requirements for frequency support capability specified in the Grid Code. A careful selection of the part-load point ensures that the gas turbine will operate at an optimum efficiency without being unduly stressed. (8 pages)TIGER: a model based and rule based real-time tool for monitoring and diagnosis of dynamic systems
http://dl-live.theiet.org/content/conferences/10.1049/ic_19950111
The TIGER project is developing a set of advanced tools for real-time monitoring and diagnosis of dynamic systems, with particular emphasis on gas turbine condition monitoring. The project's two applications are the most advanced gas turbine condition monitoring systems in use. These are developed by combining real-time rule-based technology with qualitative simulation and model-based diagnosis. (4 pages)Teesside Co-generation Project and Dowty Digital Protection Scheme
http://dl-live.theiet.org/content/conferences/10.1049/ic_19950421
This paper is in two halves: a general overview of the Teesside Project followed by a description of the Dowty protection system between the generating units and the two gas installed substations. The Teesside Power Station is by far the largest independent power station in the UK. It comprises an 1875 MW combined-cycle gas turbine cogeneration plant (CCGT) and has the giant ICI Wilton site as a steam host. The authors describe the main features of the plant, the balance of the plant, process control and staffing. The authors then describe the Dowty pilot wire interface and digital channel protection scheme. (5 pages)A high speed alternator for a small scale gas turbine CHP unit
http://dl-live.theiet.org/content/conferences/10.1049/cp_19950879
With a gas supply in 17 million homes in Britain, there is scope for wide use of CHP in the home. Designs aimed at this market, using Stirling engines or thermoelectric generators, suffer from high initial costs and/or low efficiency. To circumvent this problem, a novel design has been developed using a turbocharger operating as a small gas turbine with the basic constituents of a gas fired central heating system. By coupling an alternator directly to the turbocharger shaft the necessity for gears is removed, reducing power losses and lubrication needs within the unit. This required the development of a high speed alternator with output power in the range 500 W to 1 kW, rotating at a shaft speed in the range 50000 to 150000 rpm. Several direct drive turboalternators have been built previously with small scale outputs in the range of 3 to 30 kW. Few have been designed to produce outputs below 1 kW. This paper describes the design and construction of a 500 W, ultra high speed alternator for a small scale, direct drive CHP unit. Experimental results of low speed testing are also given. The following aspects of the alternator are discussed: magnets, winding losses, generated voltage frequency, retainment shells, and output power.On-line monitoring of rotor shorted turns
http://dl-live.theiet.org/content/conferences/10.1049/cp_19941094
Large generators for use with steam and gas turbines are subject to high mechanical and electrical stress which may lead to deterioration of the insulation. The rotors, in particular, may develop short circuits and there is a need for the operators to be aware of this situation. The manner in which shorted turns can occur in the rotors of generators and the difficulties associated with monitoring for such shorted turns are indicated. An online monitor which has been developed to solve this problem is described together with some operating experiences which have been learnt from the use of it.Controlling co-generation
http://dl-live.theiet.org/content/conferences/10.1049/cp_19940165
The control system for the Gulf Oil co-generation project, as well as its design and commissioning are described. The paper first outlines principles which are important to the success of a project. It then uses the Gulf Oil co-generation project to show how some of these may be applied in practice. To fully appreciate the issues involved in the project the overall context needs to be understood. Thus the paper gives an overview of the process and the electrical system. It focuses on the control system. The development of the control system is traced from the high level conceptual design to the detailed design of one component, the modulating boiler control.Robust control of a 1.5 MW free turbine with complex load: nonlinear closed loop simulations
http://dl-live.theiet.org/content/conferences/10.1049/cp_19940303
This paper describes the results of nonlinear closed loop simulations of a 1.5 MW free turbine with complex load. The nonlinear model is developed within SIMULINK from details previously presented by Biss and Grimble (1993). The generalised H<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">∞</sub> (GH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">∞</sub>) and classical controllers, implemented within the paper, were previously designed and applied in the above paper to linearised models of the engine. The performance of the controllers when applied to a nonlinear model in the presence of a severe load disturbance are compared with the predictions of the linear closed loop simulations discussed in the above paper. The nonlinear model includes constraints on the magnitude of the manipulated variable. The results show that the GH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">∞</sub> controllers provide better disturbance attenuation than the classical controllers in the absence of manipulated variable constraints, as predicted by the linear simulations. However when the range of the manipulated variable is limited in some cases the GH<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">∞</sub> controlled system becomes unstable whereas the classical controllers are still able to satisfy the majority of the performance requirements.Optimal coordination of stochastic hydro and natural gas supplies in midterm operation of power systems
http://dl-live.theiet.org/content/journals/10.1049/iet-gtd.2010.0215
This study presents a stochastic security-constrained unit commitment (SCUC) model for the optimisation of coordinated midterm water and natural gas supplies. The stochastic model considers random outages of system components, load forecast errors and water inflow uncertainty, which are modelled as scenarios in the Monte Carlo simulation. Water resources may be used in winter to cover gas unit outages caused by an insufficient gas supply. However, those hydro units then may not be available for peak load shaving in the following summer if the summer happens to be a dry season. Thus, water reservoirs would have to be utilised efficiently throughout the year to provide substantial cost reductions while maintaining the power system reliability. The proposed model also considers the impact of midterm security-constrained scheduling of water and gas on the power system reliability. Accordingly, hourly SCUC is incorporated in the reliability calculation. The proposed stochastic problem is formulated as a two-stage optimisation in which the first stage optimises the water and gas usages in the first month and the second stage considers the schedule via multiple scenarios in the following 11 months. Numerical simulations indicate the effectiveness of the proposed stochastic approach for the optimal scheduling of midterm water and gas usages.Basic investigation of a high-speed vacuum circuit breaker and its vacuum arc characteristics
http://dl-live.theiet.org/content/journals/10.1049/ip-gtd_20045276
A high-speed vacuum circuit breaker that can interrupt a fault current quickly by superimposing a high-frequency inverse current on the fault current to force current to zero is investigated. A requirement on the vacuum arc characteristics and its interruption capabilities for the circuit breaker are also studied. The requirements of the high-speed vacuum circuit breaker are estimated by an analysis of the excess torque calculation of a gas turbine generator under various fault conditions. Basic experiments on the vacuum arc characteristics and its interruption capabilities are conducted to clarify whether such vacuum arc might be applied to the high-speed vacuum circuit breakers.