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# 1999 IEEE Transmission and Distribution Conference (Cat. No. 99CH36333)

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Displaying Results 1 - 25 of 78
• ### 1999 IEEE Transmission and Distribution Conference [front matter]

Publication Year: 1999, Page(s):0_1 - xvi
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• ### An effective-resistance measurement technique for improving the current-cycling test of power connectors

Publication Year: 1999, Page(s):616 - 622 vol.2
| | PDF (611 KB)

The current-cycling tests as prescribed by the ANSI C119.4 and CSA-C57 standards have been in use for many years by utilities in the US and Canada to evaluate the performance of electrical connectors. Although these standards can provide some satisfactory level of assurance for the users, their evaluation criteria are, however, not sensitive enough to detect the contact degradation. As a consequen... View full abstract»

• ### Author index

Publication Year: 1999, Page(s):0_4 - 0_6
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• ### Substation battery options-present and future

Publication Year: 1999, Page(s):518 - 522 vol.2
| | PDF (476 KB)

Alternatives to vented lead-acid batteries for substation duties are presented. Currently available battery options include valve-regulated lead-acid and nickel-cadmium. Future options include nickel-metal hydride, lithium-ion and lithium polymer. Advantages and disadvantages are discussed for each type, as they relate to this application View full abstract»

• ### Application of electronic secondary technologies to 1000 kV gas-insulated switchgear and transformers

Publication Year: 1999, Page(s):509 - 516 vol.2
| | PDF (620 KB)

To achieve the target of starting operation at the beginning of the twenty-first century, 1000 kV GIS and transformer were developed. From the viewpoint of enhancement of reliability and rationalization of operation and maintenance, not only the primary equipment but also the secondary equipment such as electronic current and voltage transformer and monitoring sensors for 1000 kV equipment are the... View full abstract»

• ### Very fast transients in 1000 kV gas insulated switchgear

Publication Year: 1999, Page(s):501 - 508 vol.2
Cited by:  Papers (8)
| | PDF (648 KB)

For 1000 kV transmission system, disconnecting switches (DSs) fitted with resistors and high-speed grounding switches (HSGSs) were developed. At the UHV Equipment Test site, DS surge and HSGS closing surge tests were conducted. Then, the very fast transient overvoltage (VFTO) controlling performance of the DS and the surge voltage level due to HSGS closing were confirmed. In the same tests, the su... View full abstract»

• ### Field tests on current carrying performances of 1000 kV GIS

Publication Year: 1999, Page(s):495 - 500 vol.2
Cited by:  Papers (1)
| | PDF (480 KB)

Field tests on 1000 kV (UHV) gas insulated switchgear (GIS) substation equipment have been conducted. This paper presents mainly the results of a temperature rise test which demonstrates the mechanical reliability of the GIS. The specified value of induced current of the enclosure and shunt bars among phases is set as much as 100% of rated normal current. The average temperature of four points def... View full abstract»

• ### Composite insulation technology for new compact 72/84 kV C-GIS

Publication Year: 1999, Page(s):489 - 494 vol.2
Cited by:  Papers (6)
| | PDF (456 KB)

This paper presents a composite insulation technology for a new compact 72/84 kV C-GIS-cubicle type gas insulated switchgear. The dielectric characteristics of a composite insulation structure composed of low-pressure SF6 and epoxy are shown. It is clarified that this structure is effective in increasing withstand voltages in nonuniform electric fields and that they can be further incre... View full abstract»

• ### Multi-objective optimization of a neural network based differential relay for power transformers

Publication Year: 1999, Page(s):476 - 481 vol.2
Cited by:  Papers (6)
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An application of artificial neural networks (ANNs) to the protection of three-phase power transformers is presented in this paper. The emphasis is placed on selecting the appropriate type of an ANN as well as pre- and post-processing algorithms. More than 30 essentially different architectures have been developed and tested in this paper: from natural relaying signals to highly pre-processed logi... View full abstract»

• ### Effect of load parameters on the harmonic performance of distribution networks

Publication Year: 1999, Page(s):784 - 790 vol.2
Cited by:  Papers (1)
| | PDF (736 KB)

This study addresses the effect of the load parameters, such as its density, power factor, its daily load curve and the eventual presence of power factor correcting capacitors, on the frequency characteristics of the input impedance of a radial distribution network. The network is supplying a load area of a rectangular shape via a feeder and several laterals. A closed-form expression for that impe... View full abstract»

• ### Real time simulation of CT's in a current differential protection scheme

Publication Year: 1999, Page(s):470 - 475 vol.2
Cited by:  Papers (2)
| | PDF (448 KB)

The Jiles/Atherton phenomenological model of a ferromagnetic material is used in the simulation of current transformers (CTs) in a differential current protection scheme. The results of simulation studies for a two CT scheme are compared to waveforms recorded during practical tests View full abstract»

• ### An approach to constructing sensitivity indices and fuzzy control of system voltage and reactive power

Publication Year: 1999, Page(s):759 - 764 vol.2
Cited by:  Papers (3)
| | PDF (504 KB)

This paper presents the results of research aimed at improving the efficiency of coordinated online control of system voltage and reactive power on the basis of developing models, methods and a control system, integrating traditional numerical techniques with fuzzy logic technology. An approach associated with experimental design is considered to construct diverse types of sensitivity indices, whi... View full abstract»

• ### A new lossless circuit balancing the MV distribution systems from insulated shield wires of HV lines

Publication Year: 1999, Page(s):722 - 728 vol.2
Cited by:  Papers (1)
| | PDF (448 KB)

Three-phase scheme shield wire lines (MV lines obtained by isolating 2 shield wires of an HV transmission line) are intrinsically unbalanced. Even though the load supplied is balanced, negative sequence components of the voltage are originated by this asymmetry. Balancing means are necessary in order to contain these components to tolerable values. The paper presents a new balancing circuit, made ... View full abstract»

• ### Resonance in inhomogeneous transmission lines using travelling waves

Publication Year: 1999, Page(s):778 - 783 vol.2
| | PDF (528 KB)

The paper presents an analytical procedure for estimation of resonance frequencies in inhomogeneous transmission lines. The procedure is based on a new approach which is based on the fact that the phenomenon is characterized by an algebraic sum of travelling current waves at the beginning of the line. Two typical cases of discontinuities on a practical transmission line are considered: a transpose... View full abstract»

• ### Fault section estimation in electrical power systems using artificial neural network approach

Publication Year: 1999, Page(s):466 - 469 vol.2
Cited by:  Papers (16)
| | PDF (300 KB)

Fault section estimation is important for a power system to be restored to its normal state after a faulty section is isolated. In this study, an artificial neural network based approach is proposed to estimate the faulty section in power system by using the information from the protective relays and circuit breakers. The proposed approach is applied to a sample system where bus, transformer and l... View full abstract»

• ### A thermal model for optimized distribution and small power transformer design

Publication Year: 1999, Page(s):925 - 929 vol.2
Cited by:  Papers (5)
| | PDF (404 KB)

A thermal model for the design of rectangular layer windings for transformers is summarized. The model calculates thermal gradients across layers, to and from the core, and from the no-duct region under the core iron to the ducted region. The model evaluates the effects of cooling duct quantity, location, and size on the thermal performance. The model includes temperature dependent fluid propertie... View full abstract»

• ### Composite insulators are gaining ground-25 years of Swiss experience

Publication Year: 1999, Page(s):827 - 833 vol.2
Cited by:  Papers (5)
| | PDF (640 KB)

This paper presents the newest applications of silicone composite insulators which are finding increasing use not only in Switzerland, but also in the power industry worldwide. These applications include interesting designs for railway overhead lines, medium voltage lines, and 400 kV high voltage overhead transmission lines. Solutions are presented for high-voltage outdoor equipment, which have be... View full abstract»

• ### Field experience with multigas on-line monitoring of power transformers

Publication Year: 1999, Page(s):895 - 900 vol.2
Cited by:  Papers (4)
| | PDF (440 KB)

Dissolved-gas analysis has long been recognized as the best method for the detection and identification of incipient faults in power transformers. This diagnostic method has progressed one step further with the introduction of the TNU on-line multigas monitor. Field demonstration has been in progress since June 1997 on a critical transformer of the Manitoba Hydro power system. On-line multigas mon... View full abstract»

• ### A mixed back-propagation/Marquardt-Levenberg algorithm for optimizing the distribution electrical systems operation

Publication Year: 1999, Page(s):753 - 758 vol.2
Cited by:  Papers (2)
| | PDF (368 KB)

This paper presents a new methodology to be applied to the distribution electrical systems optimization for reducing the resistive electrical losses of the systems in real-time. This methodology combines the best features of two known algorithms (back-propagation algorithm (BP) and Marquardt-Levenberg algorithm (ML)) for improving the convergence of artificial neural networks (ANN) training. Since... View full abstract»

• ### An alternative procedure for the design of high voltage overhead transmission lines: sensitivity analysis, constrained design and line upgrading through tower reconductoring

Publication Year: 1999, Page(s):715 - 721 vol.2
| | PDF (368 KB)

In a previous publication by the author (1999), a method was suggested for the proper selection of the number and radius of the line's subconductors, the bundle configuration as well as the main tower dimensions of HV and EHV lines. The objectives of this follow-up paper are: (1) the application of the above procedure to study the sensitivity of the line's transmitted power to changes in its condu... View full abstract»

• ### A new application concept of transmission line arresters to 500-kV lines

Publication Year: 1999, Page(s):681 - 686 vol.2
Cited by:  Papers (2)
| | PDF (552 KB)

More than half of the electrical faults on transmission lines are caused by lightning in Japan. In order to improve their lightning performance, gapped type transmission line arresters have been installed in many service lines since 1986. It is general that the arresters are installed on three phases of one circuit of double-circuit transmission lines to prevent interruptions of supply due to ligh... View full abstract»

• ### Accurate calculation of thyristor-controlled series compensator impedance

Publication Year: 1999, Page(s):654 - 657 vol.2
Cited by:  Papers (1)
| | PDF (264 KB)

This paper derives an accurate analytical expression of the fundamental-frequency impedance of a thyristor-controlled reactor when used as part of a transmission line series compensator. The formula is a function of thyristor firing angle, line inductance, and compensator capacitance. A numerical example illustrates the accuracy of two approximate expressions at different levels of line compensati... View full abstract»

• ### Harmonic balance based bifurcation analysis of three-phase ferroresonance with full scale experimental validation

Publication Year: 1999, Page(s):772 - 777 vol.2
Cited by:  Papers (4)
| | PDF (424 KB)

The determination of ferroresonant oscillations in circuits with voltage transformers is a highly nonlinear problem due to the possible core saturation. It is achieved with an algorithm based upon the harmonic balance method in the frequency domain. Advantages over a time domain description are discussed. Branches of solutions in relevant parameter planes can be continued beyond bifurcation points... View full abstract»

• ### Monitoring changes in system variables due to islanding condition and those due to disturbances at the utilities' network

Publication Year: 1999, Page(s):460 - 465 vol.2
Cited by:  Papers (4)  |  Patents (1)
| | PDF (444 KB)

The continuous growth in embedded generation (EG) has emphasised the importance of being able to reliably detect loss of mains (LOM) especially when the EG is islanded' with part of the utility network. Current methods of detection have not proved completely dependable, particularly when the islanded' load's capacity matches that of the EG. This paper is the result of an investigation, using the... View full abstract»

• ### Field studies of dynamic thermal rating methods for overhead lines

Publication Year: 1999, Page(s):842 - 851 vol.2
Cited by:  Papers (17)  |  Patents (2)
| | PDF (716 KB)

Dynamic thermal circuit rating (DTCR) is a method of monitoring and dynamically uprating existing transmission circuits. This paper describes the results from a series of field tests of the overhead line module of the software at a number of unique field test sites. This initial analysis of field data, which is essential to establishing the functionality, accuracy, and reliability of the method, a... View full abstract»