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Power Delivery, IEEE Transactions on

Issue 2 • Date April 1995

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Displaying Results 1 - 25 of 64
  • Bibliography of switchgear literature: IEEE committee report

    Page(s): 824 - 844
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1880 KB)  

    This bibliography was prepared by the IEEE Recognition and Planning Subcommittee of the IEEE Switchgear Committee to be used as a reference for switchgear education. The references generally cover the period of mid-1988 through mid-1992. The last complete switchgear bibliography was published in 1989 covering the period through June 1985. This reference is updated at five year intervals.<> View full abstract»

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  • Bibliography of relay literature, 1993 IEEE committee report

    Page(s): 684 - 696
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    The latest of a series of classified lists of power system relaying references, begun in 1827, is presented. This bibliography is in continuation to the bibliographies of relay literature which were published previously and are contained in the references given for volumes of the IEEE Transactions.<> View full abstract»

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  • Fault testing of gapless zinc oxide transmission line arresters under simulated field conditions

    Page(s): 786 - 796
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    Gapless zinc oxide (ZnO) transmission line arresters were fault tested under simulated field service conditions to address important reliability issues associated with their application. Specific reliability issues addressed were: (1) failure mode or pressure relief capabilities; (2) the ability of the arrester fault isolation device to isolate a faulted arrester from the system while simulating a high speed line reclosing operation; and (3) verification that the evolving fault is restricted to the faulted phase only and does not involve adjacent unfaulted phases. An important and unique aspect of this test was to demonstrate how the complete assembly, made up of an actual 100 kV tower structure, arrester and associated elements, would perform by documenting results for each of the three reliability issues noted. Test results address important user application issues impacting system reliability and suggest potential focus areas for future standards development work View full abstract»

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  • Design, implementation and testing of an artificial neural network based fault direction discriminator for protecting transmission lines

    Page(s): 697 - 706
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    This paper describes a fault direction discriminator that uses an artificial neural network (ANN) for protecting transmission lines. The discriminator uses various attributes to reach a decision and tends to emulate the conventional pattern classification problem. An equation of the boundary describing the classification is embedded in the multilayer feedforward neural network (MFNN) by training through the use of an appropriate learning algorithm and suitable training data. The discriminator uses instantaneous values of the line voltages and line currents to make decisions. Results showing the performance of the ANN-based discriminator are presented in the paper and indicate that it is fast, robust and accurate. It is suitable for realizing an ultrafast directional comparison protection of transmission lines View full abstract»

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  • Practical distribution transformer models for harmonic studies

    Page(s): 906 - 912
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    Transformer models for distribution network harmonic studies based on rated parameters are presented. Results from simulations and measurements on power transformers are compared. Sensitivity studies are carried out to show how the total harmonic distortion of current and voltage behaves as a parameter of the transformer change. A field test involving a transformer as part of a power system feeding a DC motor drive was used to compare simulations and measurements. Both agreed reasonably well View full abstract»

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  • Temperature rise tests on a forced-oil-air cooled (FOA) (OFAF) core-form transformer, including loading beyond nameplate

    Page(s): 913 - 923
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    Results of temperature rise tests performed in accordance with PC57.119/Draft 12, Recommended Procedures for Performing Temperature Rise Tests on Oil-Immersed Power Transformers at Loads Beyond Nameplate Ratings, are presented. Tested data is compared with calculated values using IEEE and IEC loading guide equations and exponential power constants are determined and are compared with those given in the loading guide. Discussion is offered that may be useful in future drafts of and to the users of the proposed test procedure View full abstract»

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  • An improved non-inductive impulse voltage measurement technique for ZnO surge arresters

    Page(s): 778 - 785
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    One of the most important parameters of the protective performance of ZnO surge arresters is the residual voltage. In laboratory tests on standard arresters, a thin ZnO disc with a central hole is used in order to pick up the voltage, and a system with a double shielding technique reduces outside effects. Comparative tests of voltage signals from this series divider with those from a conventional parallel connected divider show that inductive overshoot is avoided View full abstract»

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  • Transient analysis of distribution class adaptive VAr compensators: simulation and field test results

    Page(s): 1119 - 1125
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    Simulation studies are performed to analyze the transient behavior of the adaptive VAr compensator (AVC), a power electronic device installed at the distribution level, during its design, installation and field testing stages. The simulation model includes detailed models for power apparatus, power semiconductor devices and low signal level electronics. Hence, by using this model, a wide range of simulation studies which contribute towards the development of the AVC and its effectiveness in the field can all be performed on the same platform. A new power electronics simulator called SABER has proven to be very effective for this study because of its model-independent structure and extensive library that covers various disciplines of engineering. The simulation studies are aimed at gaining a better understanding of the interaction between the AVC and the distribution system. They cover a range of phenomena such as switching transients due to mechanical capacitor bank closing, fast transients due to reverse recovery of the power diodes of the AVC, power system harmonics and voltage flicker problem. This paper also briefly describes the criteria for selection of the simulation tool and the models developed View full abstract»

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  • Reduction in distribution transformer failure rates and nuisance outages using improved lightning protection concepts

    Page(s): 768 - 777
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    This paper presents a case study of an overhead distribution feeder in a very high keraunic area. The feeder was experiencing approximately twice the number of lightning caused transformer failures per year than any other distribution feeder in the area. In an attempt to lower the outage rate and the repair costs, the lightning protection for this feeder was studied and a new protection system was installed. The first section of this paper discusses the outage history of this feeder and existing transformer overvoltage protection. It then details the steps that were taken to improve the protection so acceptable customer service could be achieved. The interruption data results for one year after the protection changes were implemented are then presented. The results from the field trial of the new lightning protection scheme exhibit a significant improvement in the feeder service reliability. The last section of this paper is a compilation of teardown data of failed distribution transformers. The analysis includes failed transformers from the study feeder, and failed transformers from the same electric utility, but not part of the feeder study. The causes of the transformer failures were tabulated. The results from the teardowns indicate that a high percentage of distribution transformers with interlaced and noninterlaced secondary windings fail from low-side voltage surges View full abstract»

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  • A survey of optical channels for protective relaying practices and experience

    Page(s): 647 - 658
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    The Optical Channels for Protective Relaying Working Group of the IEEE Power System Relaying Committee performed a survey of industry practices for applying optical channels, both planned and installed, for protective relaying communications. This report summarizes the sizes of the existing and planned optical fiber network, the types of construction, whether the relaying channels are on dedicated fiber or multiplexed with other services, experience, and maintenance practices View full abstract»

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  • Development and practical operation of perfluorocarbon immersed 275 kV transformers with compressed SF6 gas insulation

    Page(s): 880 - 888
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    A perfluorocarbon (PFC) immersed 275 kV power transformer with compressed SF6 gas insulation has been under development. This paper clarifies the AC partial discharge inception voltage and time characteristics of PFC immersed insulation and also clarifies that a prototype 275 kV 100 MVA three-phase transformer could be operated without any trouble during long-term overvoltage tests. This prototype proved that it had AC partial discharge inception strength of higher than 1.5 times the AC test voltage and lightning impulse breakdown strength of 1.5 times the test voltage. A 275 kV, 250 MVA three-phase power transformer was developed and operated at the outdoor substation of the Chubu Electric Power Co., Japan. This transformer has been successfully operated to date and a detailed internal inspection of the transformer was carried out after one year and 9 months of successful practical operation. No significant abnormal condition was recognized View full abstract»

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  • Application of advanced after-laying test to long-distance 275 kV XLPE cable lines

    Page(s): 567 - 579
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    Long-distance XLPE cable lines were laid over a distance of 26.9 km using the newly established 275 kV XLPE cable technology and in-situ jointing technique. Field AC HV withstand testing was conducted on these lines as the after-laying test-the first such test for long-distance EHV XLPE cable lines. For this test, small resonance type AC withstand HV test equipment was developed. A new system was also established for direct and simultaneous measurement of partial discharge over the entire cable length. One latent defect was detected in this test, proving that the test method is extremely effective in confirming the quality of XLPE cable lines View full abstract»

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  • Transient model and simulation in three-phase three-limb transformers

    Page(s): 896 - 905
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    When a three-phase three-limb power transformer, whose primary windings are Y-connected with isolated neutral, is energized or reclosed by asynchronous closure of the circuit breaker poles, the transient voltage at the still disconnected transformer terminal and the transient current flowing from the connected windings may reach considerably high values. This can cause serious damage to equipment connected to the transformer. This transient phenomenon is closely related to the switching sequence of the circuit breaker poles, switching-on angles, remanent flux and the magnetic saturation characteristics of the transformer's iron core. This paper presents a simple and effective method to predict the transient phenomenon of power transformers. The proposed method formulates a model to represent the transient under various operating conditions. Simulations and experiments are both demonstrated to support the proposed method View full abstract»

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  • The application of AM/FM system to distribution contingency load transfer

    Page(s): 1126 - 1135
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    A geographic information management system (GIS) is applied to perform the automated mapping and facility management (AM/FM) of power distribution systems for contingency load transfer. Three phase load flow analysis is used to calculate the current flows of line switches by retrieving the network topology and facility attributes which have been stored in the AM/FM database. The current flows solved are then stored in the database as the attributes of line switches for load transfer analysis. When a system contingency such as a fault or overload occurs, the load transfer is then executed to find the switches to be operated by the heuristic search method while subjected to the system operation rules. By the proposed method, the network topology can be easily updated and displayed in the computers by the connectivity trace routine according to the switching operations. Since all the system facilities are stored in the AM/FM database according to the actual spatial coordinates, it provides practical information for the system operators and crews to allocate and operate the switches easily. To demonstrate the effectiveness of the integrated AM/FM system with application programs for distribution operation, a distribution system of Taiwan Power Company (Taipower) in Kaohsiung downtown area is selected for case study. It is found that contingency load transfer for distribution system operation can be enhanced significantly with the application of AM/FM systems to determine the switches to be operated and the corresponding spatial locations of the switches View full abstract»

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  • Electromagnetic interference with electronic apparatus by switching surges in GIS-cable system

    Page(s): 739 - 746
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    Thyristor malignitions and protector relay failures caused by gas circuit breakers closing in the gas insulated switchgear (GIS) of a power cable system could not be controlled by reducing the ground impedance or adding surge absorbing capacitors. As a result, a study was carried out on this problem with a 66 kV mock-up apparatus installed in a factory. It was found that malignitions and failures such as those mentioned above could be controlled by preventing 10 MHz ultra high-frequency surges emitted by the GIS from leaking out into the grounding system View full abstract»

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  • Methods for protecting employees and others from electrical hazards adjacent to electric utility vehicles

    Page(s): 950 - 960
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    Electrical hazards related to electric utility vehicles working adjacent to a power line are generated from two sources: from induction due to the proximity of the vehicle to energized facilities, or an accidental contact between the vehicle and energized parts. The magnitude of the current and voltages, and thus the related hazards are quite different. Methods of minimizing the hazard and are discussed in the paper. Isolating the work site by barricading is the best method for protecting the public. Complete isolation is not practical for the worker. Grounding the vehicle will reduce the vehicle voltage but the resulting current flow will create step and touch hazards. Isolation from the grounding points and limitation of the time a work has contact with the vehicle are very desirable methods of protection View full abstract»

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  • Development and field testing of an adaptive flicker controller for 15-kV systems

    Page(s): 1025 - 1030
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    An adaptive flicker controller (AFC) device is developed and field tested. The AFC control strategy is described for systems with large and rapidly varying loads connected to a weak feeder. The control algorithm does not require knowledge of system parameters such as line impedance. The algorithm is fast and adaptive to system variations. The AFC is tested in a utility distribution system having a severe voltage flickering problem. The hardware and software required to implement the AFC is discussed. The results of a field test are presented and analyzed View full abstract»

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  • Transformer model reduction using time and frequency domain sensitivity techniques

    Page(s): 1052 - 1059
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    The paper investigates the use of sensitivity methods to identify the parameters of reduced transformer models. The reduced model retains the structure of the original model. The identification is performed in both the time domain and the frequency domain. The technique is applied to a lumped-linear model of an experimental coil, and the results are promising View full abstract»

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  • Reduction of stray currents and magnetic fields from single-phase power distribution systems

    Page(s): 1112 - 1118
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB)  

    This paper describes a simple, straightforward method for reducing stray currents and external magnetic fields from single-phase power distribution systems through the installation of a 1:1 current transformer. The current transformer magnetically couples the phase conductor and neutral conductors of a power cable, thereby forcing the return current to travel through the neutral rather than through other paths. Furthermore, if the phase conductor and neutral are sufficiently close together (preferably concentric), the magnetic field created by the return current in the neutral cancels the field created by the current from the phase conductor, thereby eliminating magnetic fields. This isolates the power cable from its environment while allowing it to remain solidly grounded. The current transformer may be applied to all sizes of power distribution systems, from underground residential distribution systems to wiring within buildings. This paper explains the theory behind this method, discusses possible practical applications of the method, and reports the results of a test installation by the City of Austin. These results show that the method can virtually eliminate stray currents and magnetic fields emanating from power distribution systems. However, more research should be done before the method is put into practice View full abstract»

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  • Equivalent resistivity of non-uniform soil for grounding grid design

    Page(s): 759 - 767
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    This paper develops a method to determine the equivalent resistivity of heterogeneous soils to be used in the available expressions for uniform soils employed to calculate the ground resistance, mesh and step voltages of substation grounding grids. The results obtained with the proposed equivalent resistivity are compared with the results obtained from the two layer and the multilayer models of the soil and with the results from a computer program, developed by the authors, directly based on the potential produced by a point source in heterogeneous soil View full abstract»

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  • Design of HVDC converter stations with respect to audible noise requirements

    Page(s): 747 - 758
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    The purpose of this paper is to provide an overview of the engineering methods, tools, design solutions and verification methods used in the design of HVDC converter substations subject to acoustic requirements. The sound generation section of the paper describes how the sound power level radiated from electrical components can be calculated based on the load. The sound propagation section describes how the sources affect the sound pressure level at emission points of interest. A method to break down the acoustic requirement to the component level and practical studies to verify the concordance with the requirements are also illustrated. Different solutions for screening and absorption are described as well as measurement methods. The paper also describes a working method used to fulfil outdoor acoustic requirements View full abstract»

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  • Insulation recovery time after fault arc interruption for rapid auto-reclosing on UHV (1000 kV class) transmission lines

    Page(s): 1060 - 1065
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    The insulation recovery time after arc interruption must be known in order to select an adequate reclosing dead time of rapid auto-reclosing on transmission lines. The flashover probability of the insulation recovery voltage obtained from the insulation recovery tests using full size insulator assemblies was calculated. The insulation recovery time at the fault point for rapid auto-reclosing on UHV (1000 kV class) transmission lines was estimated View full abstract»

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  • Linear, lumped parameter transformer model reduction technique

    Page(s): 853 - 861
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    The behavior of large power transformers under transient conditions is of significant interest to both transformer designers and power system engineers. The designer employs computer programs to construct detailed electrical models enabling him to compute the transformer's internal transient voltage distribution. Using this information, and various other tools, the design engineer can develop a reliable and cost effective insulation structure. The power engineer requires a reduced model that accurately represents the transformer's behavior to investigate the effects of power system transients. Reduced models are generally obtained either from detailed design models, or from measurements on fully constructed transformers. The latter technique has the major disadvantage that in the absence of an expensive prototype design, improvements cannot be made. Presently, both methods are subject to varying degrees of error. This paper presents a reduction technique that starts with the linear, detailed design model, and provides a reduced model of any specified size, while retaining the same computational accuracy as the original model. The method is mathematically exact, relatively straight-forward and compatible with time domain transient analysis programs. Application of the technique to the detailed model of a 765/345/34.5 kV, 500 MVA single phase autotransformer is provided View full abstract»

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  • Simulation of transient sheath overvoltages in the presence of proximity effects

    Page(s): 1066 - 1075
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    The series impedance needed in the simulation of power cable transients is commonly calculated using formulae that neglect the presence of proximity effects. Further, when applying these formulae, sheaths constructed as wire screens must be treated as tubular conductors. This paper investigates how these simplifications affect the occurrence of transient sheath voltages. The analysis involves calculations by the finite element method and comparison of calculated results with field measurements. It is shown that the sheath voltages are dependent on the proximity effect and the helical winding of the sheath wires View full abstract»

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  • Interphase power controller adapted to the operating conditions of networks

    Page(s): 961 - 969
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    This paper introduces a new family of interphase power controllers (IPC) for which the useful portion of the Prsr characteristics are shifted as the power transfer level is increased. Thus, the power characteristics of a specific IPC application can be adapted to the operating conditions of the power network. The response of the IPC is compared to those of the two conventional technologies used in building it: the phase-angle regulator; and series compensation. It is shown how the natural response of the IPC regulates active power passively, without the need for control action. Also, reactive power can be controlled independently of active power slowing for better voltage control. The new IPC retains the inherent qualities of previous IPCs View full abstract»

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Aims & Scope

Installation and operation of apparatus, equipment, structures, materials and systems for the safe, reliable and economic generation, transmission, distribution, conversion, measurement and control of electric energy.

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Meet Our Editors

Editor-in-Chief
Wilsun Xu
Ph.D., P.Eng.
Dept. Electrical and Computer Eng.
University of Alberta
(9107 - 116 Street)
Edmonton, Alberta T6G 2V4 Canada
wxu@ualberta.ca
Phone:780-492-5965
Fax:780-492-1811