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Gas turbines are usually started by a DC motor or an air motor. Either system is available for most turbines up to about 20 MW. Occasionally AC motors are used. Beyond 20 MW, when heavy industrial machines tend to be used, it becomes more practical to use air motors or even diesel engine starters. DC […]

The electrical engineer should take full account of the site location and environmental conditions that a gas turbine generator will need to endure. These conditions can seriously affect the electrical power output that will be achievable from the machine. The starting point when considering the possible output is the ISO rating. This is the declared

The fuels usually consumed in gas turbines are either in liquid or dry gas forms and, in most cases, are hydrocarbons. In special cases non-hydrocarbon fuels may be used, but the machines may then need to be specially modified to handle the combustion temperatures and the chemical composition of the fuel and its combustion products.

There are basically two gas turbine driving methods, known as ‘single-shaft’ and ‘two (or twin) shaft’ drives. In a single-shaft gas turbine, all the rotating elements share a common shaft. The common elements are the air compressor, the compressor turbine and the power turbine. The power turbine drives the generator. In some gas turbines, the

At the earliest practical time in a project the engineers will need to identify areas of engineering and design where interfaces are necessary. An efficient system of communication and exchange of information should be established and implemented at regular intervals. Meetings should be arranged to discuss problem areas and short-falls in information. The following generally

• Switchboards and motor control centre name and tag number. • Bus-section numbers or letters. • Cubicle numbers or letters. • Line voltage, number of phases, number of wires, frequency, busbar continuous current rating. • Busbar nominal fault breaking capacity in kA at 1 or 3 seconds. • Identification of all circuit breakers, fuse-contactor units,

Single-line diagrams are the most essential documents that are developed during the detail design phase of a project. They identify almost all the main items of power equipment and their associated ancillaries. Initially they define the starting point of a project. Finally they are a concise record of the design, from which all the design

The rating of a motor should exceed that of its driven machine by a suitable margin. The selection of this margin is often made by the manufacturer of the driven machine, unless advised otherwise. The actual choice depends on various factors e.g. Approximate rating of the motor or machine (kW) Margin of the motor rating

Some basic and important points, in relation to a modern power system, are summarized below: 1. Generation, transmission and distribution of electric power in our country is carried out as 3-phase system at 50 Hz. 2. Three most important conventional methods of power generation in out country are: coal based thermal plants, Hydel plants and

Nuclear power plants are thought to be the solution for bulk power generation. The present day atomic power plants work on the principle of nuclear fission of 235U. In the natural uranium, 235U constitutes only 0.72% and remaining parts is constituted by 99.27% of 238U and only about 0.05% of 234U. The concentration of 235U