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With the power shortage and nonavailability of power at certain locations, the use of captive power is becoming more common. In fact, every industry has their own standby generating sets. Utilities like post and telegraphs, airports, etc. use engine-alternator sets as emergency power supplies. Due to the development of technology, varied types of new electrical equipments have come in use. With the...
Standby power plant reliability is critically tested during commercial AC failures. Malfunctions can be costly or disastrous. Typically system components are tested and maintained to standards, but the entire power plant as a system is only tested during a commercial power outage. This paper presents unique procedures devised in our company to simulate power failures without an actual outage. The...
After the examination of Fuel Operated Generator's function in conventional and in alternative energy power systems, the authors have studied the power systems optimization from reliability, economic and operational points of view. Then, the more important parameters of Fuel Operated Generator's and associated power systems were identified. Particular attention was given to the acquisition, analysis...
The importance of the DC voltage limits specified for a DC to AC corverter (inverter) is analysed. Sealed and vented battery performances, when the above limits are changed, are compared. Benefits and disadvantages regarding cost, efficiency, inverter design and their consequences are discussed.
The demanding requirements, innovative design, and high performance of a sophisticated optical fiber splicer are described. The power supply is required to produce complex and highly controlled voltage/ current waveforms under the control of an integrated microprocessor. The same microprocessor is also used to manipulate optical fibers in three dimensions so as to produce a solid splice with low optical...
A modern international telecommunication center employing high tech communications equipment requires a very reliable and sophisticated power system. This paper highlights the underlying design philosophy of the power system of a typical international telecommunication center in Canada. Salient specifications of the power system and its components are provided. This is followed by a brief description...
The paper deals with tracking control with forecast of modulation inverters and static power frequency changers. There is described a way and presented an exemplary circuit designed for emitting a forecast signal. Mathematical principles of the control under examination as well as exemplary currents and voltages, corresponding to the control, at the loads of the modulation inverter and static power...
KDD, an international telecommunications carrier in Japan, has several switching centers. The largest one is located at KDD Shinjuku Building in Tokyo. In this building, many telecommunications systems are installed for various services such as telephones, TELEX and data communications. Once the power supply fails, these telelcommunications services are severely damaged. Therefore, an emergency power...
The Canadian Standards Association is a non-profit organization dedicated to the writing of Standards, and Certification of products to these Standards. Although CSA Standards are voluntary, with reference to telephone equipment power supplies compliance to the applicable Standards is made mandatory by the Canadian Federal and Provincial Governments. These are electrical safety Standards addressing...
The continuing development of new converter technologies has meant a rapid evolution of the power supplies used in telecommunications equipment. Supplies using these new technologies operate at ever higher frequencies and are potential EMI sources. In concert with this technological development, regulatory bodies such as the FCC have set new or tighter standards to limit EMI problems. This combination...
The principle of Pulse Width Modulation (PWM) has been well known for decades. A patent was actually issued in 1944, but it was not until the early sixties that the principle began to be widely applied to power conversion. Today the PWM principle is applied extensively in the power conversion field. However, the full advantage of this principle, as applied to inverters, can only be realized by appropriate...
Growing sophistication in critical telecommunication and other modern computerized equipment requires uninterrupted power. This necessitates an uninterrupted transfer capability between normal and alternate sources of power, such as utility and engine-generator. Such a transfer is easily accomplished between two compatible sources (for example between two sources connected to the same bus feeder)...
As equipment has become more compact and reliable, it is essential that the power supply unit also be compact and reliable. In the past, the use of high frequency switching was one way to miniaturize power supply equipment. In recent years, MOS FET has been developed, enabling switching up to several megahertz. This now requires that the optimum switching frequency be determined. Since parts have...
The emergence of new technologies for power processing plants has complicated the selection process for power equipment. During the evaluation of power systems, one has to look at the advantages and disadvantages of various technologies, their impact on redundant systems and the reliability real or calculated. Also system costs usually dictates where trade offs have to be made. This paper deals with...
This paper describes a pulse current generator that provides a high current under low output voltages. This generator is basically a DC to DC converter with an intermediate high frequency AC link; it makes use of two devices called dual thyristors with a LC resonant circuit operating above its resonant frequency. After giving a brief description of the properties of the dual thyristor, the authors...
Common methods of balance criterions according to the linear theories are widely spread in SMPS development - despite the fact, that we have to deal with extremely nonlinear circuits, as for instance power switches and similar. The reason for the relatively successful applications of linear theories to nonlinear systems lies in fairly large distance between the high switching frequency on one hand...
Computer program simulation and the results of experimental work have been used to study and predict the thermal performance of equipment shelters. A light weight shelter served by a pumped water storage cooling system is the type of shelter modelled. The shelter provides a standby room temperature limiting capability. This is required when high heat dissipating digital communications equipment is...
This paper describes the thermal analysis performed at the French Telecommunications Research Centre, regarding a new mechanical rack used for an optical fibre terminal: the BR 10 rack. BR 10 is constructed in the form of a beam to which receivers and transmitters are fastened. Each unit is fitted with two printed circuit boards, which are plugged in horizontally. An experiment was first conducted...
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