By Topic

Energy Conversion, IEEE Transactions on

Issue 3 • Date Sep 1993

Filter Results

Displaying Results 1 - 25 of 36
  • A novel self-exited self-regulated single phase induction generator. II. Experimental investigation

    Page(s): 383 - 388
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    Part I of this paper presents the basic system, theoretical modelling and typical test results of a novel self-excited self regulated induction generator. In this part, the results of a detailed experimental investigation are presented to assess its suitability for practical applications. The steady state performance of the self-excited single phase induction generator, maintaining the terminal voltage within a close range is investigated under realistic loading conditions in the laboratory. Detailed experimental results are presented and discussed. Necessary tests to obtain machine parameters for theoretical modelling are also developed and relevant results of the prototype presented. The effects of series and shunt capacitors, prime mover speed, load and load power factor are investigated. It has been shown to exhibit a better voltage waveform as compared to commercially available sets. The experimental results confirm that this new generating system can be favourably employed for use as a small portable generator driven by nearly constant speed prime movers such as oil engines or hydro turbines View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hydro turbine transfer functions with hydraulic coupling

    Page(s): 527 - 532
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    The authors deal with the development of transfer functions for hydraulic turbines connected to a common penstock. These turbines tend to be hydraulically coupled. Both the solid mass approximation and the pressure wave modelling approach are applied for the development of diagonal and coupling transfer functions. This modelling approach is applied to the Stratos hydroelectric power station, China. It is shown that the solid mass approach gives relatively simple rational transfer functions that accurately represent the hydraulic coupling between turbines over a wide frequency range View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Proposed Iceland/United Kingdom power link-an indepth analysis of issues and returns

    Page(s): 566 - 575
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1068 KB)  

    This paper examines issues and makes an indepth engineering analysis of the profit which would be expected from electricity from Iceland using possible scenarios considering variables which could impact on the viability of the link. Considered is fluctuation of pool purchase price over half-hour periods of a complete year, discount rates, nonfossil fuel premiums, possible price movements in future years, and carbon taxes which it is expected could be imposed by the time the link is operational, as well as capital which is tied up during construction periods, availability of plant, and transmission losses etc. It is concluded that the link is viable for all but the very worst scenarios, but if development costs could be reduced by 10% or more the link would be more attractive to developers and investors on account of uncertainty and risk involved, unless EC and governmental guarantees are forthcoming. These conclusions are in agreement with an independent assessment which has recently been made by an International Energy Consulting Group View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of single phase induction generators

    Page(s): 389 - 395
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    The paper describes the performance of an isolated self-excited single phase induction generator when the excitation capacitor is connected to one winding and the load is connected to the other. Depending upon the equivalent circuit, nonlinear simultaneous equations of the magnetisation reactance and operation frequency, have been used for computer simulation of the two cases. Newton Rhapson numerical methods have been found suitable for the solution of the equations. Computer results have been supported by laboratory tests. The models have been used to study the effect of machine parameters on the general performance of the machine View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Eddy current and impedance evaluation using a two-dimensional finite element method

    Page(s): 362 - 368
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB)  

    A finite element method is developed to evaluate cylindrical electromagnetic fields due to eddy currents inside linear conducting media. Boundary conditions are imposed in an integral form combined with Neumann conditions. The method is applied to a periodic system of slot embedded conductors in the rotor of an induction machine and is verified by comparison with an analytical method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determination of the parameters representing the cross-magnetizing effect in saturated synchronous machines

    Page(s): 333 - 342
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (764 KB)  

    This paper introduces the concept of the cross-magnetizing phenomenon in saturated synchronous machines (the magnetic coupling between the direct and quadrature-axis). The parameters which represent this cross-magnetizing effect are defined and techniques for determining these parameters are proposed. In these techniques, there is no need for an auxiliary winding in the q-axis of the machine and, thus, they can be applied to conventional synchronous machines. Experimental results which verify the accuracy of these techniques are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lab and field tests of a self-tuning power system stabilizer

    Page(s): 476 - 483
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    Digital power system stabilizers have opened new avenues for applying innovative control strategies to damp generator rotor oscillations at steam and hydroelectric power plants. This paper describes test results from simulation studies and field tests where a self-tuning control algorithm was tested using a digital stabilizer. The simulation studies indicated a marked improvement in local mode damping and a contribution to damping at the inter-area mode while initial tests at power plants gave promising results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Battery energy storage for frequency regulation in an island power system

    Page(s): 455 - 459
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (292 KB)  

    Large battery energy storage (BES) facilities may provide significant dynamic operation benefits for electric utilities. One area in which a BES facility could be useful is the frequency regulation requirement. This feature is significantly important for island power systems. The purpose of this paper is to quantify the effects of a 30 MW battery on the frequency regulation in the Israeli isolated power system. The study was performed on a single area model representing the whole power system and containing a first order transfer function that represented the BES performance View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time test results with adaptive speed controllers for a diesel prime-mover

    Page(s): 499 - 505
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    Self-tuning adaptive control algorithms, that employ explicit dead-time identification techniques, have been discussed in the literature vis-a-vis the diesel-driven power prime-mover. Such algorithms are numerically intensive owing to the complicated identification algorithms. This paper discusses the implementation of the above mentioned algorithms on a Texas Instruments' DSP 320C30 based system. This digital signal processor has sufficient numerical capability to carry out all the real-time computations at sampling intervals of 10 ms. It can also perform well in the matters of speed measurement and control generation without any significant additional hardware. The results of real-time tests are compared with that obtained using the Woodward Governor Company's 701 prime-mover controller View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comparison of turbine-generator shaft torsional response predicted by frequency domain and time domain methods following worst-case supply system events

    Page(s): 559 - 565
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (704 KB)  

    The paper examines precision of predicting time response for torque in turbogenerator exciter shafts by frequency-domain analysis following incidence and clearance of short-circuits etc on the electrical supply system. The analysis is based on Fourier analysis of generator air gap torque following incidence and clearance of a supply network disturbance or following worst-case mal-synchronisation to obtain torque excitation which acts on the generator rotor corresponding to each modal vibration. Amplitude and phase of each vibration is thereby determined. Using appropriate damping, time responses for shaft torque at each shaft cell is constructed by summing components which correspond to each frequency of modal vibration of the shaft. These time responses are compared with those obtained by solution of more than 50 differential equations which simulate the shaft train, turbine, generator, exciter, electrical supply system, the fault clearing process, the turbine governor, and the generator excitation system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A step-down chopper-controlled slip energy recovery induction motor drive

    Page(s): 396 - 403
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (680 KB)  

    The design of a chopper-controlled slip energy recovery drive, also known as a static Kramer drive, demands an exact knowledge of the steady state and dynamic performance of the system over the complete operating range. To accomplish this, a coupled circuit approach is necessary whereby the self and mutual coupling effects, voltage and current harmonics in the machine and voltage and current ripple at different points in the drive system are duly taken into account. Such a model should enable the accurate prediction of all instantaneous current values which leads to accurate prediction of electric torque and harmonics injected into the supply. This paper presents a model to accomplish the above. Mathematical predictions are verified with experimental results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modeling of emergency diesel generators in an 800 megawatt nuclear power plant

    Page(s): 433 - 441
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (616 KB)  

    Computer models have been developed of emergency diesel generators and their associated emergency core cooling system induction motors during sequencing and results compared with field tests. Models required to perform studies of emergency diesel generators in a nuclear plant are presented. Field measurements indicating different response of two seemingly identical generator excitation systems are discussed. Results of 480 volt AC contactor dropout testing are provided for determining voltage limits in the 480 volt system during motor starting transients View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A novel self-induced self-regulated single phase induction generator. I. Basic system and theory

    Page(s): 377 - 382
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    This paper describes a newly developed single phase capacitor self excited induction generator with self regulating features, suitable for oil engine driven portable gen-sets for autonomous/standby power generation. The system is also suitable for microhydel and wind energy systems. The generator has two specially designed stator windings in quadrature, connected externally to a shunt and a series capacitor respectively. It employs a standard die-cast squirrel cage rotor. Special features, advantages and theoretical concepts of the system are highlighted View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Application of Floquet's theory to the analysis of series-connected wound-rotor self-excited synchronous generator

    Page(s): 369 - 376
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (500 KB)  

    In this paper, Floquet's theory for solving differential equations with periodically varying coefficients has been utilized in evaluating the steady state performance of a three phase wound rotor series-connected self-excited synchronous generator SCSESG. This type of generator is practically realized by the series connection of stator and rotor windings of a conventional wound-rotor induction machine. Self excitation may occur when a suitable capacitor bank is connected across the machine terminals. The analysis gives the same results that are obtained when the d-q transformation model is utilized. Application of Floquet's theory has the advantage of reducing the mathematical manipulation needed. The results are checked experimentally. Saturation effects on each axis inductance as well as iron losses show satisfactory agreement. The generator acts as a hypothetical salient pole machine operating at half the rotor electrical angular frequency and is independent of load conditions provided that the prime mover speed is kept constant View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Control by variable rotor speed of a fixed-pitch wind turbine operating in a wide speed range

    Page(s): 520 - 526
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    Variable rotor speed control of a fixed-pitch wind turbine is investigated on a system consisting of a wind turbine which can operate in a wide speed range, from 0 to 38 RPM. It produces any desired output from the rated (20 kW) to no-load, providing there is enough wind. A special technique is used to determine the operating point of the wind turbine by using the measured rotor speed and power. A difficult problem with this type of wind turbine control is to make the upper speed limit reasonably high to capture as much energy as possible but still low enough to avoid power peaks View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pipe crawling inspection robots: an overview

    Page(s): 576 - 583
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (948 KB)  

    Pipe crawling inspection robots (PCIRs) are playing an important and expanding role in remote testing and inspection of 4 in. to 8 ft. diameter pipes. PCIRs provide the power, process and pulp industries with an economical and time-saving approach to inspection of insulated, buried or inaccessible pipes. Three locomotive mechanisms of PCIRs, commonly-employed nondestructive testing (NDT) sensors and techniques, as well as field deployments are discussed in this paper View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimum design of longitudinal field variable reluctance motors-application to a high performance actuator

    Page(s): 357 - 361
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    A new structure is defined for variable reluctance motors; it is based on the concept of longitudinal or tangential field. A mathematical model is given, and is used to define the optimum pattern. A high performance linear actuator has been built on these principles; predicted values have been checked against experimental data View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comparison of power system stabilizers for damping local mode oscillations

    Page(s): 533 - 538
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (568 KB)  

    The Bureau of Reclamation has examined the damping of local mode oscillations using three types of power system stabilizers (PSS): internal frequency; electrical power; and accelerating power. Comparisons of operating characteristics such as PSS output noise and sensitivity to load changes are also included. Results are based on the analysis of field test data and analog computer simulation, Methods that can be used at remote sites during PSS alignment tests have been employed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The power system planning in Japan: an international perspective on the future of power systems

    Page(s): 546 - 551
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB)  

    The Japanese energy "Outlook" was formulated June 1990, by the Energy Advisory Committee to the Ministry of International Trade and Industry, as a policy intended as a reference and a goal for all Japanese to make every effort to achieve. The author describes how, in order to implement the national energy policy in combination with the "Outlook" programme, a long-term electric power facilities development plan (the "Mono-Plan") was authorized by the Central Electric Power Council (CEPC) as an annual rolling plan. CEPC is organized by ten major power utilities including EPDC, to coordinate activities of electric utilities in Japan. One important role of the Council is to give advice to the Government in terms of power system planning, development and management. The above mentioned "Outlook" includes "Mono-Plan" as basic data View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimum matching of direct-coupled electromechanical loads to a photovoltaic generator

    Page(s): 343 - 349
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (532 KB)  

    The objective of the paper is to present a general mathematical formulation for matching electromechanical loads connected to a photovoltaic array. An optimization method is then used to solve the matching problem with the objective of maximizing the gross mechanical energy. The analysis is extended to obtain the sizing of the array and the battery in the direct-coupled system. Results show that optimum matching can be achieved by carefully selecting the PV array rated parameters with respect to the load parameters. The rated power of the array is twice that of the load. The field constant that maximizes the gross mechanical energy can be obtained given the parameters of the load and the array temperature. The separately excited motor offers higher matching performance compared to the series motor. The rotodynamic load offers better matching compared to the viscous friction load View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reliability, cost, and performance of PV-powered water pumping systems: a survey for electric utilities

    Page(s): 506 - 512
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (684 KB)  

    Opportunities for electric utilities to utilize photovoltaic-powered systems to serve small utility and customer-owned loads have been documented by the Electric Power Research Institute and others. One application where PV-powered systems can save money for utilities and their customers is remote water pumping for ranch, farm, and domestic use. Information on system reliability, cost, and performance is key to utility management decisions regarding this alternative approach to serving their customers. A project was initiated by EPRI to obtain this information on PV-powered pumping systems installed in the western US. With assistance from three PV-pumping system suppliers, a survey was developed and mailed to 251 owners of PV-powered water pumping systems installed in the last five years. This paper presents the summary of the findings of that survey and includes information on owner preferences, system reliability and performance, and cost data View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Robotic applications in PSE&G's nuclear and fossil power plants

    Page(s): 584 - 592
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1240 KB)  

    Robots are rapidly becoming a strategic technology in the electric utility industry. Since 1983, over 200 applications of these devices have been documented, often resulting in significant time and manpower savings. In nuclear plants, these devices have reduced radiation exposure to human workers and also reduced plant downtime. Public Service Electric and Gas (PSE&G) Company is a nationally recognized leader in this technology. Since 1987, the company has spent $1.6 million on robotic hardware and development projects for use at its Salem (2 PWRs) and Hope Creek (1 BWR) nuclear plants. Savings to date from these investments has exceded $5 million. Recently PSE&G has expanded its robotic application efforts to include fossil plants, with many new concepts. This paper discusses the state-of-the-art of mobile robots in the utility industry, and use of PSE&G's pioneering work in this area as a case study; discussing the cost, performance and benefits of specific applications View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Apparatus for supplying an isolated DC load from a variable-speed self-excited induction generator

    Page(s): 468 - 475
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (696 KB)  

    This paper describes the design and laboratory testing of novel generation apparatus for supplying an isolated DC load from a self-excited induction generator operable at variable speed. The variable-speed generating apparatus consists of a self-excited induction machine, a controlled Graetz bridge rectifier, a voltage-boost power converter, and a control system. The induction generator supplies the rectifier. The voltage-boost power converter interfaces the variable output voltage of the rectifier to the fixed DC voltage required for the load. The rectifier is operated at levels of average DC current and voltage which control machine voltage to the rated AC voltage and which also draw the necessary power to supply the DC load. Performance is enhanced with respect to earlier apparatus in that both the DC voltage supplied to the load and the AC voltage on the machine are simultaneously controlled to fixed reference levels over broad operating ranges of load and speed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Value analysis of intermittent generation sources from the system operations perspective

    Page(s): 484 - 490
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (680 KB)  

    The objective of this study is to determine the economic and operational impact on energy cost of incorporating large photovoltaic (PV) and wind energy conversion systems (WECS) into the electric utility generation mix. In most cases, PV and WECS power outputs are subtracted from the utility load with the expectation that conventional generation would meet the residual load. This approach is valid for small penetration levels and/or for PV and WECS facilities connected near load centers, However, several constraints such as thermal generation characteristics, fuel supply and delivery, spinning reserve requirements, and hydro availability are not adequately represented in this process. To determine the optimal value of large-scale PV and WECS applications, a new methodology that would take into account the aforementioned constraints as well as a more global penetration is developed. Results indicate that while high hydro availability increases PV penetration levels, high ramping rates can also significantly increase penetration levels View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multiple reference frame analysis of an unsymmetrical induction machine

    Page(s): 425 - 432
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB)  

    Due to the asymmetry of the stator windings of an unsymmetrical induction motor, the equations which describe this device cannot be expressed in a frame of reference where the state variables are constant in the steady state. This prevents linearization and thereby places a stumbling block in the development of a transfer function which could be used in linear control analysis, as in servo applications. The work presented in this paper provides a means to accomplish this goal. This is achieved by eliminating the position-dependent terms brought about due to asymmetry by recognising a unique property of a combination of reference frames and by employing an averaging procedure. The resulting equations are shown to predict the performance of the unsymmetrical induction motor with the accuracy of the detailed equations. The stage is now set to develop accurate reduced-order models and linear transfer functions for unsymmetrical induction motors View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The IEEE Transactions on Energy Conversion includes in its venue the research, development, design, application, construction, installation, operation, analysis and control of electric power generating and energy storage equipment (along with conventional, cogeneration, nuclear, distributed or renewable sources, central station and grid connection). The scope also includes electromechanical energy conversion, electric machinery, devices, systems and facilities for the safe, reliable, and economic generation and utilization of electrical energy for general industrial, commercial, public, and domestic consumption of electrical energy.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Juri Jatskevich
University of British Columbia