Showing papers on "Stand-alone power system published in 1985"

Electricity metering equipment

Abstract: An electricity metering equipment wherein, in order to reduce the possibility of fraudulent consumption of electricity, there is provided in addition to the usual meter (3) for measuring the amount of electricity consumed in a load, an independent device (5) which produces a signal representative of the current supplied to the load. A comparison device (4) then compares the signal with the rate of electricity consumption measured by the meter, and an output signal is produced if there is a discrepancy which may be used to disconnect the supply and/or transmit a signal to the supply authority.

Charging for electricity in the early years of electricity supply

Abstract: The paper begins by outlining the difficulties which faced the early electrical entrepreneurs when they tried to devise methods of charging for electricity supply which were fair, accurate and economic. It discusses the alternatives to fully metered supplies, and also the arguments about the relative merits of energy and quantity meters. The major part of the paper describes the most important types of electricity supply meter and how they developed over a period of about ten years from the opening in 1882 of Edison's Holborn Viaduct electricity supply system, where meters were first used. Detailed technical descriptions of the meters are not given, but references to this information are quoted where possible. An attempt is made to show how widely the different designs of meter were used and to give the opinions of contemporary engineers about them.

Incorporation of large stochastic sources in the power system

Abstract: The paper derives techniques for online and offline computer analysis of the power system in the presence of large amounts of stochastic-source (wind, solar, tidal etc.) generation and develops an extension of the probabilistic simulation (Beleriaux-Booth) technique for use in generation expansion planning. The online techniques are employed for the assessment of spinning reserve and unloadable generation requirements and the prediction of probable system frequency deviations. The offline methods are used for energy production estimation taking account of correlation effects and the required minimum levels of conventional generation that must be on the system for regulating (load following) the continuously varying stochastic-source power generation.

Economical Considerations to the Layout of Uninterruptible Power Supply Systems

Abstract: An increasing number of critical electrical consumers in industry and commerce must have interruption- free, high-quality power supplies. As a result, uninterruptible power supply (UPS) systems have become increasingly important. Present applications cover the range of 500 VA to 500 kVA for individual units and by using parallel units, outputs of up to 2.5 MVA have already been reached. By provision of redundancy and also emergency power generators, an extensive series of modular system designs has been developed. In all cases, economy and operating availability are the prime considerations. The essential aspects of these considerations will be described for the various output series.

Some Consideration about the Practical Design of the Diesel Engine Generator in a Hybrid System as a Power Supply in Telecom Plants

Abstract: In this paper are considered parameters to be taken into account for a first approach design of a group thermal engine Diesel type coupled with an electrical generator Some considerations are made about little electrogenerator groups due to the importance of their utilization in the photovoltaic and aeolian hybrid systems So, tables are tentatively formulated with a practical character for a quick design of the systems All calculations are made in view of a given use of the station battery by the optimization of its work, taking into account all the efficiences involved, in the case of power supply of telecom load operating in cc or ca modes

Economic Considerations for Reserve Telephone Power

Abstract: Considering alternate sources of power during commercial AC power failure, telephone engineers are faced with three common options: 1) A battery reserve normally ranging from three to eight hours of DC power. 2) A stand-by engine (usually a diesel engine or turbine) to provide AC power as substitute for commercial AC. 3) A combination of the first two options. Once reliability and office integrity criteria are satisfied, it is possible to vary the extent of options 1 and 2 to achieve the most cost effective combination without jeopardizing telephone service.