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Showing papers in "IEEE Transactions on Power Delivery in 1987"


Journal ArticleDOI
TL;DR: In this article, various approaches to increasing the thermal capacity of transmission lines without reconductoring or extensive restructuring are considered. But, some problems in the application of these methods and some cautions concerning the usefulness of such time variable thermal ratings to system operators are reviewed.
Abstract: Dynamic Thermal Line Ratings is a new field of endeavor that holds much promise for electric utilities seeking to maximize existing line capacity, increase transfer capability between utilities and regions while providing adequate system security. Various approaches to increasing the thermal capacity of transmission lines without reconductoring or extensive restructuring are considered. The dynamic thermal rating (DTR) methods considered involve monitoring weather conditions so that during periods of favorable wind and ambient temperature the maximum allowable line current can be increased. The relative importance of the various weather parameters and transmission line thermal limits are discussed. Certain problems in the application of these methods and some cautions concerning the usefulness of such time variable thermal ratings to system operators are reviewed. Momentary increases of up to 300 percent and average increases in the range of 50 percent above traditional static thermal ratings (STR) are theoretically possible. Actual increases may be considerably less. In particular, the ability to place monitors in those spans which limit the whole line rating due to clearance or annealing limits on the line has not been demonstrated. Also, concerns about operation of conductors at higher average temperatures and the system operator's need for a reliable estimate of thermal capacity some hours into the future are noted.

48 citations


Journal ArticleDOI
TL;DR: In this article, the results of a program of tests carried out in a number of laboratories on artificially contaminated insulators using the clean fog method are reported and analyzed, and the effects of fog generation characteristics, insulator coating variability, and calculation method are considered.
Abstract: The results of a program of tests carried out in a number of laboratories on artificially contaminated insulators using the clean fog method are reported and analyzed. The effects of fog generation characteristics, insulator coating variability, and calculation method are considered. The analysis shows that a high level of reproducibility can be achieved. Requirements are given for ensuring that the reproducibility and repeatability of the method are adequate for its acceptance as a standard testing procedure.

35 citations



Journal Article
TL;DR: In this article, the Thin-Wire Time Domain (TWTD) code and the Waterloo Analysis and Design (WATAND) code were combined into a new 3D time domain computer code.
Abstract: The Thin-Wire Time Domain (TWTD) Code and the Waterloo Analysis and Design (WATAND) Code were combined into a new three-dimensional (3-D) time domain computer code. Based on the new computer code a 3-D time domain model of lightning was proposed. The lightning model was verified during the 1985 lightning season by measurements conducted at the CN Tower in Toronto. Using the new model, it is possible for the first time to correct the lightning current for the presence of towers and to predict the current distribution along a lightning channel.

12 citations



Journal ArticleDOI
TL;DR: In this article, the authors summarized the results of an industry survey of gas insulated equipment protection practices and developed recommendations where necessary, including the use of gas monitoring equipment (alarm and/or trip), unique relaying protection applications and unique operating procedures.
Abstract: This paper summarizes the result of an industry survey of gas insulated equipment protection practices and develops recommendations where necessary. Tables are included to show the type of gas insulated equipment located at each substation (current transformers, voltage transformers, switches, bus bars, bushings, lightning arresters, and cable end terminations), the equipment configuration (single or three conductors), the type of gas monitoring equipment used (density or pressure), the use of gas monitoring equipment (alarm and/or trip), unique relaying protection applications, and unique operating procedures. Gas insulated circuit breakers are specifically excluded from this survey.

1 citations


Journal ArticleDOI
TL;DR: The paper provides guidelines for performing switching surge field tests on EHV systems and initial work towards development of a more comprehensive guide on this topic is begun.
Abstract: The paper provides guidelines for performing switching surge field tests on EHV systems. Objectives for the field tests are identified. Requirements for the test plan, test procedures, instrumentation, and test documentation are analyzed. The paper is the result of initial work towards development of a more comprehensive guide on this topic.