New Publications are available for Hydroelectric 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.Intelligent integration based on optical telecommunications to optimize distributed generation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0751
In recent years, COLOMBIA (like other countries) has gradually increased its energy demand while incorporating new sources of distributed generation, especially sources regarding small hydropower plants (SHP). SHPs in Colombia have a capacity of up to 25000 MW. However, including the 200 PCHs installed recently, the country only takes advantage of only 1% of this power. Because Colombia is vulnerable to climate changes, especially changes in river flows associated with distributed generation, the great challenge to exploit SHP-based generation potentiality is to provide stable integration of SHPs with the existing electrical systems of distribution. In order to optimize power dispatch as a function of the weather conditions and power system contingencies, it is necessary to monitor and exchange critical information between the distribution network operators and the distributed generators. This exchange requires high reliability and fast response times in the communication networks between the distributed power generators and the companies (operators) running distribution systems. The solution presented in this article, based on recent developments in Colombia, suggests that communication networks based on optical infrastructure are an effective long-term solution that proves suitable for the current challenges of such intelligent networks, such as the integration of distributed generation. These networks facilitate the operation of the whole electrical system, providing highly reliable communications and enhanced capacity as well as low latency and a good level of OPEX. The solution presented shows the advantages of using optical communication networks for the integration of distributed generation and power operation systems in both the medium and long term. Additionally, guidelines on the implementation of such integration are provided. (4 pages)Integration of distributed generation into mv distribution grid in Norway - the Namsskogan case
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0774
Integration of DG into MV distribution grids in Norway means integration of small hydro power units. Most of the DG potential in Norway is located in rural areas with weak MV grids and low consumption. This paper describes the situation in Norway regarding integration of DG into the MV grid. The paper also describes the challenges DSOs face regarding integration of DG and a particular case from Namsskogan is used as an example. (4 pages)Potential of small hydro power plants for delivering ancillary services in Germany
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0763
A high penetration of renewable energy sources leads to a higher demand on ancillary services. To ensure the stability of the network, new approaches need to be developed. Small run-of-the-river hydro power plants offer the opportunity to control the network voltage by reactive and active power. Furthermore, the units can participate on the power balancing market to ensure the operation of the transmission system. For this purpose, the main aspects of ancillary services are presented. Especially, the fundamental regulatory requirements for control reserve and for voltage control are descripted. The efficiency of voltage control in medium and low voltage networks by reactive power variation is investigated in a case study. Thereby, the reachable deviation by this control measure is determined considering high feed-in and high load scenarios, respectively. The deliverable control energy of small hydro power plants is estimated and evaluated concerning the fundamental technical aspects. Especially, the potential for the control reserve capacity for each TSO will be analysed. (4 pages)Intelligent monitoring and energy management platform of new energy power station in the islands
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0759
The new energy power station in the islands is the central node with the ocean current energy,wind energy, solar energy,energy storage equipment and other types of new energy power generation confluencing, achieved intelligent monitoring and energy management for new energy power in the islands.Refer three layer and two network architecture of smart substation,presents the islands's new energy power monitoring and energy management platform architecture,describes specific function and implementation method of the new energy power station with process layer,spacer layer and energy management layer.Based on the IEC 61850 (Second Edition) and IEC 61400-25 standard,the new energy power stations in the islands were standardized modelling,to ensure the platform standard and open. (4 pages)Impact of voltage phase angle changes on low-voltage ride-through performance of DG-units
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0871
Based on computer simulations of a simplified radial 132, 66 and 22 kV system including a 5 MVA hydro power unit, it is concluded that the assessment of the unit's fault-ridethrough (FRT) capability should be based not only on a voltage magnitude profile, but also on the change in the voltage phase angle. It is assumed that erroneous conclusions might be the result when FRT-capability studies are performed for distributed generation without taking into account the influence of the phase-angle change in this context. Further work will be conducted in order to quantify the effect of phase angle influence on the FRT capability of distributed generation units. (4 pages)The comparison and analysis for loss of excitation protection schemes in generator protection
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0071
Loss-Of-Excitation (LOE) condition of a generator may cause severe damages on both generator and the interconnected systems. This paper analyses the behaviours of different LOE protection schemes, such as R-X, G-B, P-Q and U-I schemes, for a hydro generator, which is connected to an infinite bus. Based on the simulation results, the reliability and stability of existing LOE protection schemes are compared and a preferred scheme is selected. An improvement to the scheme is also proposed to prevent the LOE relay incorrect operation during external faults, such as short-circuit faults on busbar or transmission lines. (6 pages)Alternate hydro electric dam system called TejWell
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0352
This paper as a solution to world energy needs presents a new type of dam system called TejWell dam. The dam takes advantage of Hydraulics principles to achieve operational objectives. This paper provide a theoretically solution invention of this new kind of dam. Calculations of a prototype dam are provided in this paper which provides for calculation of characteristics needed by dam. The calculations describe how the characteristics of vital parts vary with dam's height and volume. This solution is very much feasible not only on theory and paper but seems practical also. These kinds of dams if built will not cause any ecological disaster. These kinds of dams will also not displace people unlike conventional dams. These dams can be built in sea, rivers, wells, ponds, anywhere where there is water with some depth. So these dams can solve the world energy problem. A theoretical prototype model is calculated in this paper which looks feasible.On the dynamics of an hydropower generator subjected to unbalanced magnetic pull
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0032
Eccentricity leading to unbalanced magnetic pull (UMP) in electrical machines is a significant concern in industry. The UMP is known to be composed of two components: A radial component and a tangential one. Models that are used in industry currently tend to include the radial component alone. In this paper, a Jeffcott rotor model together with a new UMP model that incorporates both radial and tangential UMP constituents is studied for an industrial hydropower generator. Characterising the UMP as springs permits the model to inherit UMP stiffness contribution. Interesting dynamics are observed with the new model for a wide range of external forcing frequencies. It is shown firstly that the new UMP model is sensitive to forcing frequency in the rotor movements. Moreover, complex dynamics in the displacements of the rotor are observed for some forcing frequencies and it is noted that the rotor does not need to be forced by frequencies above its critical speed for this less desirable motion to occur. Eigenvalue-based stability analysis is performed and shows that damping of the rotor and of the bearings are important when non-synchronous whirling of the rotor is considered. Accounting for both components of UMP is an important cornerstone in the generation of better rotor design parameters which can help to curb rotor-stator malfunction and can contribute in the design of long lasting rotors to the betterment of hydropower technology.Improved PSO for short term hydrothermal scheduling
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0384
This paper addresses short-term scheduling of hydrothermal systems by using Particle Swarm Optimization (PSO) algorithm. Particle Swarm Optimization is applied to determine the optimal hourly schedule of power generation in a hydrothermal power system. The developed algorithm is illustrated for a test system consisting of one hydro and one thermal plant respectively. The effectiveness and stochastic nature of proposed algorithm has been tested with standard test case and the results have been compared with earlier works. It is found that convergence characteristic is excellent and the results obtained by the proposed method are superior in terms of fuel cost and computation time.Making small high-penetration renewable energy systems work - Scottish island experience
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0186
The power systems on the Scottish islands of Eigg and Foula are presented. These systems were designed by Senergy Econnect Ltd and Wind and Sun Ltd, and make use of SMA's Sunny Island battery inverter to generate a three-phase reference power supply. The renewable generation is sited at various locations around the network, and includes synchronous hydro generation, asynchronous hydro generation, inverter-connected wind turbines, and inverter connected PV arrays. Diesel generators are controlled automatically by the Sunny Island inverters to meet demand when renewable output is insufficient. Autonomous load control equipment allows surplus renewable power to be diverted to heating loads when it is available. The paper identifies the technologies which have made these systems achievable, outlines some issues associated with implementing such systems and highlights lessons learned. (7 pages)Optimal economic emission hydrothermal scheduling based on black hole theory and annual profit analysis considering FGD
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0171
An improved black-hole particle swarm optimization (IBHPSO) algorithm is proposed for solving economic emission hydrothermal scheduling (EEHS) problems minimizing fuel cost and emission simultaneously. The water transport delay between connected reservoirs and valve-point loadings are considered in the model formulation. In addition, all the constraints of multi-chain cascaded reservoirs including water discharge rate limits, water dynamic balance constraint and reservoir storage volume limits are handled without any penalty factor. The proposed IBHPSO algorithm has been carried out on a classical test system consist of four cascaded hydro plants and three thermal plants. The results demonstrate the feasibility and effectiveness of the proposed approach for solving the EEHS problems. Moreover, according to related environmental policies of power enterprises in China, the calculation model of annual profit with fuel gas desulphurization (FGD) is established. And the annual profit with and without FGD is compared. Besides, an incentive mechanism is proposed to obtain proper sewage charge and proper desulphurization power price. (6 pages)Power generation by using point absorber wave energy converter coupled with linear permanent magnet generator
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0935
The paper presents the design procedure and modeling of performance for a special coupled electromechanical system, for use in sea wave energy extraction applications. The electromechanical system is consisted of a linear permanent magnet generator (LPMG), combined with a cylindrical floating buoy moving due to the sea wave incidence. The basic advantage using LPMG for sea wave energy extraction applications is that the generator exploits directly the vertical movement of the incident sea wave. In such a case, the linear generator is directly coupled with a vertical cylindrical buoy in heave. This topology involves a lighter and simpler mechanical system, in comparison with a complex system that converts the vertical linear movement of the sea wave to rotation, in case that a rotating generator is used. In order to efficiently exploit the wave energy using a point absorber like a floating buoy, it is important to tune the movement of the coupled mechanism, with the main frequency of the incident wave by using appropriate control. The system analysis requires particularly developed electromagnetic mechanical hydraulic simulation models for the time variation representation of the system's operational parameters. (5 pages)Design and commissioning of a 30 kW direct drive wave generator
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0022
The Trident Energy TE 5 is a prototype wave energy converter operating on the principle of having direct-drive linear generators mounted above the water surface, coupled to floats moving under the rig deck. This paper describes aspects of the TE 5 design, including its generators, power electronic systems and the conception of its marine structure. (6 pages)Fuzzy control of micro hydro power plants
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0084
The villages have hundred households who had to use costly diesel generator sets to get access to electricity. With setting up of micro hydro power plant, the villagers are able to not only save money but also generate employment opportunities. However, micro hydro generating units are usually isolated from the grid network and require control to maintain both the frequency of the voltage waveform and the scheduled power, for any working conditions, constant. The aim of the present work is to design a fuzzy controller that would manage almost the whole operation of the generating unit. The presented fuzzy controller has three main tasks. First, it regulates the frequency output of the plant in spite of changing user loads. Second, it limits the waste of the available water. Finally, it manages the electricity distribution by dividing the mini network on different departures connected by order of priority. Results obtained by simulation show the controller ability to control the system much better than some controllers proposed in the literature. It guarantees closed loop stability at all operating conditions. The used model for simulation was constructed based on the mathematical equations that summarize the behavior of the plant and was validated based on a micro-hydro power plant prototype. (6 pages)Novel permanent magnet linear generator topology for wave energy conversion
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0018
A novel topology for a permanent magnet linear generator for wave energy conversion is proposed. It aims to increase power density and to eliminate uneven air gap flux distribution caused by the longitudinal ends; this is done by eliminating stator and rotor yokes and by introducing a new flux path. Analytical and FEM studies are used to analyse the concept and to compare it to existing machines. Results and design challenges are discussed. (6 pages)Attractiveness of hydropower project in the Philippines: the public-private partnership
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1782
The National Power Corporation's (NPC) experience in quickly resolving the power crisis that hit the country during the late 80's and early 90's can be largely attributed to the involvement of private enterprise in putting in place a number of power plants to support NPC's existing but aging plants. This initial success has prompted NPC to adopt a policy of tapping private capital for implementing generation projects identified in the Power Development Plan, with the view that ODA funding can be best utilized to implement the needed backbone transmission lines of the country. This also fits well with the government's long term plans of eventually leaving generation projects to private sector. The merits of hydropower as an alternative power source have long been recognized by NPC due to the unique benefits it offers. Aside from being indigenous and renewable, it is cheap source of energy in the long run considering its long useful life and low operational cost. And above all, its contribution to perform regulating function for the power grid because of its inherent technical characteristics makes it more desirable. The Build-Operate-Transfer (BOT) arrangement is, however, difficult for a hydropower project. Unlike a thermal alternative, the characteristics of a hydro do not sit well with the BOT structure. The challenges, therefore, are adapting the unique characteristics of hydropower to this arrangement, and developing a firm process by which NPC can encourage private developers to risk their capital. This paper will present the incentives the Government of the Philippines offered to the private investors who are willing to take the risk of developing renewable energy, particularly hydropower, in the context of BOT scheme. Likewise it will present the initiatives of the government of the Philippines is doing in order to further promote the development of renewable energy. (11 pages)Development of Kurobe River No.4 hydropower plant as a milestone of electrical engineering in Japan
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1244
The postwar Japan's greatest class project of constructing the Kurobe River No.4 hydropower plant and the Kurobe Dam began in 1956, and was completed in 1963. In this article, the social background, historic overview, technological/social significance, and distinctive features of these huge facilities are described. The pioneering works devoted to this monumental project brought a great contribution not only to the stable power supply against serious power shortages and growing power demands but also to the postwar development of industries and the enhancement of the quality of life. (8 pages)Hydro-Quebec's distribution vision and roadmap 2008-2023
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0626
This paper presents Hydro-Quebec's distribution vision and roadmap. First a quick overview of the inputs (industry benchmark, customers' expectations, Quebec's context...) that were used to build the vision and roadmap will be described. Then from these inputs, business objectives were stated by Hydro-Quebec's management. To meet these objectives, the vision selected a set of applications and technologies. It covers the overall evolution of the distribution system by proposing strategies for asset management, data management and technology management. Finally to move from today's distribution network to tomorrow's Smartgrid, the vision and roadmap shall evolve to consider influence factors in the years to come. (4 pages)Dynamic response of distributed synchronous generators on faults in HV and MV networks
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0701
Connection of distributed generators (DG) on existing power distribution networks requires solution of technical, economical and regulatory issues. A brief description of current status of DG in Bosnia and Herzegovina, with special attention to the technical impact of integration of small hydro power plants with synchronous generators, is given in this paper. Dynamic response ofDG (namely small hydro power plants with synchronous generators) on disturbances in HV and MV networks is analyzed in detail. Simulations ofDG dynamic response are performed using free, open-source MATLAB/PSAT software package on a simple test model of distribution network with DG. Several scenarios are studied. Finally, areas for further research are identified and presented. (4 pages)Ocean energy: the wave of the future
http://dl-live.theiet.org/content/conferences/10.1049/ic_20080651
The power point presentation discussed the developing technology of ocean energy with design convergence on tidal but not on wave. Today's technologies will help solve the immediate needs, but we need to work hard nurturing tomorrow's low carbon technologies today. Ocean energy represents one of the more difficult forms of renewable energy to harness. The UK is leading internationally in the development of marine energy but further development investment is needed to move the technology forward. Marine energy could supply up to 2 GW of UK electricity demand by 2020 and significantly more than this by 2050. The development of ocean energy and promising ocean driven machines are briefly reviewed, their operating conditions and the suitability of different types of hydro turbines for use as power take off options, the recent international experience, and how the technology is developing. (16 pages)Voltage and frequency control for island operated induction generators
http://dl-live.theiet.org/content/conferences/10.1049/ic_20080484
Over the last few years the interest in distributed generation and island operation of small production units has increased. Many of the existing such units are hydro power stations with induction generators. These are not initially constructed for island operation, but with some extra equipment this kind of operation is feasible. In this paper the behaviour of two parallel-operated induction generators driven by hydro turbines are studied during load steps. The influence of a STATCOM based voltage regulator is also investigated and it is shown that a fast voltage regulator may not be desirable for induction generators in combination with hydro turbines. (4 pages)Ant colony system algorithm for automatic generation control of hydrothermal system under open market scenario
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070596
This paper presents the analysis of Automatic generation control (AGC) of a two-area interconnected hydrothermal system under open market scenario. It also involves the optimization of integral controller employing ant colony system algorithm (ACS). Open transmission access and the evolving of more socialized companies for generation, transmission and distribution affects the formulation of AGC problem. So the traditional AGC two-area system is modified to take into account the effect of bilateral contracts on the dynamics. The behavior of real ants has inspired the development of the ACS algorithm, an improved version of the ant system (AS) algorithm, which reproduces the technique used by ants to construct their food recollection routes from their nest, and where a set of artificial ants cooperate to find the best solution through the interchange of the information contained in the pheromone deposits of the different trajectories. This metaheuristic approach has proven to be very robust when applied to global optimization problems and is favorably compared to other solution approaches such as genetic algorithms (GAs) and simulated annealing techniques. Gain setting of the integral controller is optimized using the ACS algorithm technique following a step load disturbance in either of the areas. The performance of the proposed approach outstands positively when compared to GAs, obtaining improved results with significant reductions in the solution time.Full-scale tests of the AC transmission system to examine the new SPS complexes
http://dl-live.theiet.org/content/conferences/10.1049/cp_20060002
In order to improve the transfer capability of the 220-500 kV AC transmission system that forms the power network backbone in the Russian Far East interconnected power system, two new generation system protection schemes complexes were put into operation at the Zeya and Bureya hydro power plants. Putting into operation was accompanied by the series of full-scale tests. The peculiarities of the full-scale experiments were participation of the experts from Russia, Switzerland, Italy and the USA, and implementation of diverse phasor measurement units devices and digital fault recorders produced in different countries such as the USA, Sweden, Belgium and Russia.Determination of optimal dynamic ancillary capacity for hydro-units in the tow-part tariff system
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062078
In a traditional two-part tariff system the on-grid price is determined respectively by capacities and energies. To hydro-units, however, their functions such as peak regulations, frequency modulations, and reserves in the security and the stability of electric power systems are undervalued. In this paper, the author accounts these benefits as a dynamic ancillary capacity for the morrow on-grid competition of hydro-units in a day-ahead market combined capacities and energies auction. The success degree of capacity (SDC) and risk coefficient of waterpower generation (RCW) are introduced, and the optimal dynamic ancillary capacity is resolved with an algorithm of decision theory. Furthermore, the paper analyses how the hydrological condition and the fluctuation of price impact on the revenue of hydro-units. Simulation results show that the proposed algorithm can compensate properly the ancillary services that hydro-units take and make hydro- plants profiting on the premise of ensuring the security of electric power systems. (6 pages)Southern Africa can contribute to solving the global warming problem with its huge hydropower potential
http://dl-live.theiet.org/content/conferences/10.1049/cp_20060043
Over a decade ago, some countries joined "The United Nations Framework Convention on Climate Change" and, in 1997, their governments committed themselves to control the greenhouse gases emissions under the so called Kyoto Protocol. This paper presents strategies and solutions that Southern African countries have committed themselves in order as to address the global warming phenomenon by implementing hydropower plants within a power superhighways framework.The study of generator inter-fault based on the digital and physical simulation
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062199
The power generator is important and precious apparatus in the power system. The protective relay must operate the circuit breaker instantaneously with high sensitivity when the fault occurs in the generator. According to previous research, the fault current of inter-fault in some situation is very large. But on the other faults, the fault current of inter-fault is so small that it is difficult to be identified by relay. The construction of large capacity generators, especially for hydroelectric power generator, is very complicated and differences each other. Besides that the difficulty and complicate exist in the calculation of the fault quantity and analysis of the sensitivity of the protection scheme, the difficulty exists in the verification the correctness of calculation algorithm too. In this paper, it was introduced the researching result about the inter-fault of the power generator both using the methods based on digital simulation and physical simulation. At the end of this paper, the comparison of these two methods was given. It shows the digital and physical simulation modes using in this paper can be used in the works of design, operation and research. (5 pages)Measurement campaign and assessment of the quality of supply in RES and DG facilities in Spain
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051017
The objective of the DGFACTS project is the application of power electronic systems to improve the quality of supply (QoS) of the electrical network, in a highly distributed energy resources. Its main result will consist of the development of a set of power electronic equipment to improve the different aspects covered by the wide electrical QoS concept. This paper analyses the results of the PQ measurements performed in a small hydro-plant site in Dima, Spain. The simulation results at steady state and dynamic conditions have been compared with real measurement data, concretely with the active and reactive power measurements and with a voltage sag measurement. (5 pages)Interaction between the distribution network and the generation distributed in the case of short-circuit in the MV network
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051260
The paper presents a strategy to achieve the coordination of protections in the MV of 13.2 kV, where it is connected to a synchronous generator with a hydraulic turbine. The strategy of protection allows one to maintain the selectivity between the switches for almost all of the faults that can be presented. Also, it maintained the instantaneous reclosing function for all of the feeders to different faults in order to save fuses in the network of MT for transitory fault. Study on the short circuit currents is done to achieve the coordination of protection. (5 pages)Connecting induction generators in parallel with main synchronous generators of a hydroelectric power plant in electrical network-simulation study
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051228
This paper introduces the electrotechnical problems concerning the starting and network connection of large parallel induction generators and possible disturbances to main synchronous generators of the hydroplant and electrical transmission system. The main research method is the dynamic modelling of main machinery, flood gate (FG) machinery and transmission network. Transient phenomena during starting and their influences on the behaviour of the main machinery and electrical transmission system are simulated. The results of the study can also be utilized with other studies concerning the connecting of induction machine based distributed generation to the electrical network. (4 pages)Large hydrogenerator design using advanced tools
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040320
A more powerful optimization technique has recently been developed that enlarges the design space, optimizes the design, and further automates the design process. The new process is used to optimize the total losses in generator design with constraints on the stator temperature rise. Using this new technique it was possible to reduce the total losses by 20%. Automatic finite element mesh generators for both integral and fractional slot machines have been developed to model single and multiple pole pitches for electromagnetic field solutions. The permeance model developed recently by using combined analytical and magneto-static finite element solutions with one pole pitch model has proven to be very powerful in analyzing the sources of vibration frequencies and mode shapes. (4 pages)Strategic elements in the development of a liberalised power market
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020014
This paper has reviewed aspects of the deployment of hydro electric power generation within liberalised electricity markets and the potential for the exercise of market power. Insights, based on models and experience from established markets, have been used as background for the consideration of possible scenarios for the evolving electricity market in Romania which has a substantial hydropower component.Performance of an integrated water turbine PM generator
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020165
The experimental performance of a small 250 mm diameter novel water turbine PM generator, originally designed as a tip driven integrated thruster, was studied in a towing tank. The PM rotor of the generator forms a ring around the tips of the turbine blades. The stator is integrated into the turbine ducting. The test results show that the alternator produces about 50 W of power in a stream with a flow speed of 2 m/s at an efficiency of 35%. This performance is slightly better than that of a commercially available device. A set of nondimensional curves derived from the test results are also presented in the paper. These curves can be used to predict the performance of different sizes of this type of generator for different stream speeds. The paper discusses the potential of this type of generator in the light of these results.Reduction of voltage violations from embedded generators connected to the distribution network by intelligent reactive power control
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020036
This paper describes the construction and test of a software model of a weak rural distribution network containing embedded water turbine driven synchronous generators (EGs). The characteristics of the network and its influence are related by development of the universal power circle diagram. The delivery of active and reactive power when the EG is operated purely in automatic power factor control (APFC) is compared with that when operated in automatic power factor control modified by voltage control (AVPFC). It is shown that this combined control enables increased EG dispatch within statutory network conditions.Possible design of the Brazilian ancillary service market for generation reserves
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020071
This paper deals with the possibility of the supply of generation reserve be considered an ancillary service in the Brazilian system. The hydroelectric nature of the generating units, the energy market design and the Independent System Operator (ISO) rules for reserves are taken into account. Important aspects such as reserve types, reserve requirements, reserve allocation are addressed in order to form the basis for establishing the future market. The proposed method for reserve procurement and reserve selling is based on the Rational Buyer's method and includes several important features. The computational algorithm used to find the solution is fast enough to be adequate for a system with two hundred generators bidding for the one-hour ahead market.Operation of system double fed machine-turbine in power network
http://dl-live.theiet.org/content/conferences/10.1049/cp_20000229
The paper deals with analysis of the operation of the system composed of a doubly fed machine and a water turbine connected to the power network with constant voltage. The interaction of vector control of the electrical machine with a cycloconverter in the rotor circuit and control of the turbine at optimal speed is studied.A method for automatic voltage control (AVC) of cascaded hydroelectric power stations
http://dl-live.theiet.org/content/conferences/10.1049/cp_20000446
This paper presents work on the control strategy and algorithm for automatic voltage control (AVC) of cascaded hydroelectric power stations with multiple units and large capacities. Under the conditions that no dynamic voltage problems are considered, a method intended primarily to monitor and control steady state voltage and reactive power situation of cascaded hydroelectric power stations is proposed. A computer program based on the proposed approach is described. The numerical simulations in an off-line environment on a practical system demonstrate that the processing speed and the accuracy are completely acceptable in a practical project.Computation and experiment results of the grounding model of Three Gorges Power Plant
http://dl-live.theiet.org/content/conferences/10.1049/cp_19990647
A model for the computation of the grounding parameters of the grids of China's Three Gorges power plant (TGPP) is presented. The computation and analysis of grounding grids of TGPP are made using this model. The computation verifies that the reinforcing grid of the dam is the main body of current dissipation. It must be reliably wielded to form a good grounding grid. Experimental results show that the method and computer calculations are correct. (8 pages)PC based monitoring and fault prediction for small hydroelectric plants
http://dl-live.theiet.org/content/conferences/10.1049/cp_19980057
Financial constraints often mean that small hydroelectric plants run unattended and hence the recording and monitoring of the performance of the plant relies on, sometimes infrequent, visits by appropriate personnel. The LabView package has appeared on the market and this enables the creation of “Virtual Instruments” which can display, on the screen of a PC, measured quantities such as are required at a typical small hydroelectric power station. The use of a PC based metering scheme gives rise to numerous added benefits; the measured data can be stored in the memory of the PC to allow subsequent downloading and analysis; the data can be analysed by other software to detect and predict fault conditions, i.e. to perform a condition monitoring function; and the data can be interrogated remotely by a suitable communications link to enable analysis and monitoring, effectively from anywhere in the world. During the 1996/97 session, two final year Honours projects were running at Napier University which related to the use of affordable PC based systems, the first performing a metering function, and the second performing a fault prediction function. This paper reviews maintenance strategies and condition monitoring techniques and then describes the development and outcomes of the two projects (a generator monitoring system and a condition monitoring and fault prediction program).Integer modelling of spinning reserve requirements in short term scheduling of hydro systems: an application to power trading
http://dl-live.theiet.org/content/conferences/10.1049/cp_19971819
This paper investigates the consequences for power system operation, if links are installed between Sweden and thermal dominated power systems. The authors have applied a short term planning method to high, medium and low load scenarios. For each scenario, they calculate the consequences for different combinations of extra power exchange and the provision of spinning reserve. For different cases, they compare the operation cost, the possibility of using the links as intended and the number of start-ups of hydro units.The development of power system and power system technology in China
http://dl-live.theiet.org/content/conferences/10.1049/cp_19971798
Over the past 5 to 10 years, electric power and power systems in China have been developing rapidly. The total installed generation capacity by the end of 1996 reached 236.5GW with an annual production of 1,080 TWh which is ranked the second in the world. There are 6 inter-provincial power networks and 5 independent provincial networks in operation in the mainland of the country. The Three Gorges hydropower project is now entering a important phase of the construction and a large amount of preparation work has been completed for the construction of the Three Gorges power transmission system. The total 26 sets of generators of the Three Gorges power plant will be completely installed before the year 2010. By the year 2020, the interconnection of the power networks of the whole country will be formed based on the interconnections among the Three Gorges power system and other inter-provincial power networks. With the rapid growth of the power systems, new technologies for HVAC/DC power transmission, power system operation and control have been and will be developed and adopted.Contribution to the determination of the basic load proportion of non-centralised, regenerative power generation plants in the supply area of a regional power supplier
http://dl-live.theiet.org/content/conferences/10.1049/cp_19970609
Under the German law on energy supply, the Energieversorgung Suedsachsen AG (EVS AG) as a regional supplier with more than half a million customers for both tariff and special contractual conditions, and presupplier to 12 urban plants with a maximum mains supply of more than 920 MW has the obligation to collect and enrich energy which was generated by noncentralised, regenerative power sources. Within the framework of wind measurement programmes, a possible extension of about 360 MW was determined for the supply area of the EVS AG. Based on new developments on the wind power plant market with the clear trend to the erection of wind power plants in the country, this value seems to be feasible in the future. For water power stations, a possible, installed, total capacity of about 40 MW with an increase to come mainly from the extension of formerly shut-down plants is assumed for the future. Feeding by photovoltaic plants is not a relevant scale. In October 1996, the installed capacity of wind power plants amounted to about 34 MW, and of water power plants, to 35 MW. Since the EVS AG does not have independent generating plants, and receives the entire capacity from presuppliers, it is becoming necessary to assess the capacity potentials of noncentralised, regenerative power sources in order to obtain an information on the sum of the monthly guaranteed proportions. The quantity of the energy which is made available by regenerative energy sources at a certain time cannot be ascertained in a deterministic way. The problems arising from an offer-dependent supply can only be dealt with by methods of probability calculus. (5 pages)Pole proximity effect on EL CID results
http://dl-live.theiet.org/content/conferences/10.1049/cp_19971096
A three-dimensional finite element analysis of the magnetic field between the stator and rotor of salient-pole hydroelectric generators has shown quantitatively that end leakage flux produces distortion of EL CID (Electromagnetic Core Imperfection Detector) results, which are obtained relatively close to the side of a pole piece. The conclusion is in agreement with results obtained from two test cases. This was expected for the first machine, but a careful reappraisal of the test results for the second machine was required to establish a correlation with the 3D-FE analysis, as a pole proximity effect had not been obvious initially. The further conclusion is that EL CID results obtained with the rotor in-situ would inevitably be subject to distortion due to the pole proximity effect. Recognition of this permits it to be taken into account.Modeling for a large scale hydropower station simulator based on the object-oriented facility
http://dl-live.theiet.org/content/conferences/10.1049/cp_19971822
Because a large-scale hydroelectric power station simulator in the authors' laboratory has a special functional requirement that all simulation be generating sets oriented, generating processes oriented and whole zone station oriented, modeling of a large scale hydropower station has other characteristics in addition to general simulator modeling characteristics. The authors have used an object-oriented methodology in modeling this large-scale hydropower station and have obtained satisfactory results in some degree. The architecture of modeling for this simulator is presented in this paper.An advanced ELG for control of small scale hydroelectric generation
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960143
Micro hydroelectric sets are defined as those with unit ratings of less than 100 kW. They are often situated in remote communities, particularly in developing countries. As they are often isolated from grid networks their technical characteristics are such that they require a governor to maintain the frequency at an acceptable level for the users. This paper describes the development of a microprocessor based electronic load governor (ELG). It goes on to identify limitations in its original performance and to describe improvements in the control algorithm which have led to an advanced performance. Finally, the onsite application of an ELG is described in a case study.Expert system scheduling of cascade hydro-electric plants
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960121
The hydrological interdependence of plants in cascade hydro-electric systems means that operation of any one plant has an effect on water levels and storage at other plants in the system. Hydro plants may be dispatched to meet predicted demand, to trade electricity at a commercially opportune time, or to adjust water levels in the system. Hydrologically and commercially efficient operation of cascade systems requires that water resources and energy trading are managed simultaneously. This paper describes some of the principles of cascade water management and the development of an expert system which assists in the optimal scheduling of hydro plant within Scottish Hydro Electric plc's system.Studies on high performance inverter generation system of microhydraulic water turbine
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960144
Microhydropower energy resources is a renewable resource which could be an environmentally-sound source of energy since it requires no large scale dam construction and can coexist with its surroundings. For the purpose of utilizing renewable energy resources, the authors have focused on the inverter system that makes variable speed control possible for application to microhydraulic energy and wind energy. In this paper, the inverter generation system of a microhydraulic water turbine with variable speed control under both natural and fluctuating river flow conditions is presented and its performance is experimentally evaluated through a number of field tests. Comparison of the this inverter system with a conventional fixed-speed control system is also made to show the superiority and advantages of the variable speed control system.Feasibility study for increased power exchange between Norway and continental Europe by new HVDC links
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960340
The benefits of utilizing energy exchange between the Norwegian hydroelectric power system and the thermal power systems in Europe make it interesting to establish new HVDC sea cable interconnections. Providing the required licenses are issued by the national authorities involved, several new HVDC links may be established from the southern part of Norway to the continent each having a cable length of approximately 550 km. A total power of 3000 MW or more can then be exchanged through the HVDC links including the existing Skagerrak interconnection. It is planned to transmit a maximum power of 600 MW or even 800 MW, by each new HVDC link at a DC voltage of 500 kV assuming that progress in cable technology allows this voltage level in the coming years. A feasibility study with detailed modelling of all HVDC interconnections, the AC system of Southern Norway and relevant parts of the UCPTE system has been carried out. Especially the close electrical proximity between the converter stations in Norway (the distance between the converter stations is 40-60 km) requires detailed studies using digital simulation. In the following the advantages of energy interchange, technical aspects and the main results of the system dynamic study are discussed.A planning model with mixed integer representation of hydro and thermal plants
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960278
This paper presents a combination of mixed integer hydropower models and mixed integer thermal power models for short term hydrothermal power generation planning. The integer constraints in the hydro system derive from the start-up costs of hydro units and the fact that hydropower plants only are operated in finite number of intervals. The integer constraints in the thermal system derive from the start-up costs of thermal power plant units and the minimum generation limits for committed units. The planning problem will then be large scale and mixed integer and therefore cannot be solved by an exact method. Instead, a Lagrangian relaxation is used to decompose the problem into one subproblem for each hydro and thermal power plant. These subproblems are solved by dynamic programming. To find feasible solutions from relaxed solutions, a heuristic method based on network programming is used. The method is illustrated by a numerical example.Embedded mini-hydro generation in the water supply industry
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960142
There is widespread potential for generating modest amounts of hydroelectric power at water treatment plants in the United Kingdom water supply industry. This paper identifies some of the potential sources of mini-hydro power, reviews the applicable mechanical, electrical and control equipment and considers some of the factors influencing technical and economic viability of power generation at these sites. The institutional regulations applicable to new plants are also identified.Economic short term scheduling for a run-of-river-plant chain by combined LP and genetic optimization
http://dl-live.theiet.org/content/conferences/10.1049/cp_19960234
A simulation and optimization tool for daily operation planning of a cascaded hydro electric power plant system is proposed in the paper. To maximize the value of (weighted) energy generation subject to imposed constraints the optimal water release schedule is refined in a functional hierarchy down from a several days scope to a four hours horizon. A two-step-concept is chosen: coarse pre-optimization by linear programming, followed by a detailed optimizing search procedure, for which a self-adjusting genetic algorithm was designed. An inherent and essential part of this approach is the developed (fully) nonlinear, dynamic simulation model. Test case results and obtained performance improvements versus current scheduling practice are reported.