Power distribution lines

In earlier years, to reach a remote area, where. separate telephone lines had not been laid it was normal practice to rttn them through the same poles as the HT power distribution lines (generally 11-33 kV). This was particularly true of internal communications of the electricity companies for ease of operation and to save costs and time. This commitnication was known as the magneto-telephone system. But the proximity of telephone lines to power lines adversely affected the performance of the telephone lines due to generation of overvoltages (Chapter 20) and eleetrical interferences (conductive and inductive interferences, discussed later) on the telephone lines by the power lines.. Some of these interferenees, particularly system harmonics, had the same frequency as the audio frequency of the telephone lines and alTected their audio quality. 

The running of telephone lines through power lines is long discontinued. They are now run on separate structures within a city and nearby areas at audio frequency (— 0.3-3.4 kHz), and maintain enough distance from HT power distribution lines. They are therefore almost unaffected from such disturbances. Nevertheless, interferences must be kept in mind when installing these lines so that they are out of the inductive interference zone of the power lines. The latest method in the field of communications to avoid disturbances is to use underground optical fibre cables, where possible, as discussed later. Optical fibre cables are totally immune to such disturbances. 

Figure J shows an example of the top surface features of an MCP designed for electrooptical-signal-processing applications (33). The MCP has 18 chip attach pads surrounded by dumbbell-shaped pads for wire bonding and repair. The top surface also contains off-package I/Os along two sides, wide power distribution lines, and sites for decoupling capacitors. In this design, the package size of 2.25 by 2.25 in. (5.7 by 5.7 cm) was determined by the top-layer features rather than by the maximum interconnection density.

Litcation When possible, place electrical equipment where people and other equipment cannot contact it. For example, poles keep power distribution lines out of people s reach and above most vehicles and equipment. Buried power lines reduce the Irkelihood of contact even further. 

In order to optimize ways to protect telecommunication and power distribution lines from lighming, one needs to know voltages that can be induced on overhead wires by lighming strikes to the ground or to nearby grounded objects. NEA methods have recendy been employed to analyze lightning-induced voltages on overhead telecommunication and power distribution lines. 

Imai, Y, N. Fujiwara, H. Yokoyama, T. Shimomura, K. Yamaoka, and S. Ishibe. 1993. Analysis of lightning overvoltages on low voltage power distribution lines due to direct lightning hits to overhead ground wire. lEE Jpn.apan Trans. PE 113-6 881-888. 

Hirai, T., T. Miyazaki, S. Okabe, and K. Aiba. 2007. A study on an analysis model of grounding electrode for power distribution lines considering transient behavior. lEEJ Trans. PE 127 833-839 (in Japanese). 

Power line communication (PLC) systems use power distribution lines and cables for data communications in a frequency range up to 30 MHz. Within... 

In addition, other utiUties are installing estabUshed solar cells in a growing number of tests that may lead to a mass market. The studies may indicate the extent to which solar cells can be used to avoid installation costs for new distribution lines between conventional power plants and remote customers buildings. Also, among other objectives, PV cells may provide an economical means of helping to supply demand during peak summer periods in northern climates. 

Under such a condition, the line will maintain a unity p.f. at all points of the line and the reactive power generated, due to the distributed line charging capacitances (Co), is offset by the reactive power absorbed by the distributed line inductances (Lg). The generator is now not unduly stressed by the reactive power feedback, i.e. 

The series capacitors tire connected in series with the power lines to provide reactive control to an individual load or to a power distribution or transmission system. They are therefore switched with the pow er lines and are thus permanently connected devices. 

Relocation of service water pumps and the electrical power distribution system for immunity from steam and boiler feedwater line break... 

Utility companies have a power system network including large generating plants, overhead transmission lines, power substations which reduce transmission line voltages to distribution line voltages, and over-head/underground distribution lines which carry power to the end users (such as a production facility). 

The North American electric power transmission system has been described as the largest, most complex machine ever built by humanity. It is a massive network of generating stations, transmission lines, substations, distribution lines, motors, and other electrical loads all interdependently linked for the conversion, transportation, and control of electrical energy. Approximately 60 percent of all energy utilized in the United States passes through the interconnected electric power system. The major goal of the system is to most efficiently and reliably deliver electric power from generating stations to residential, commercial, and industrial consumers. 

The worst operating condition in a common design practice consists of overly conservative assumptions on the hot-channel input. These assumptions must be realistically evaluated in a subchannel analysis by the help of in-core instrumentation measurements. In the early subchannel analysis codes, the core inlet flow conditions and the axial power distribution were preselected off-line, and the most conservative values were used as inputs to the code calculations. In more recent, improved codes, the operating margin is calculated on-line, and the hot-channel power distributions are calculated by using ex-core neutron detector signals for core control. Thus the state parameters (e.g., core power, core inlet temper-... 

Wind Power Plant A group of wind turbines interconnected to a common utility system through a system of transformers, distribution lines and (usually) one substation. Operation, control and maintenance functions are often centralized through a network of computerized monitoring systems, supplemented by visual inspection. This is a term commonly used in the United States. In Europe, it is called a generating station. 

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