الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Electricity or Electrical power has become a major part of our daily life and without electricity we cannot imagine a life today.
Power system network consists of generation, transport and distribution of electric power not less than any of them in importance from the other, in this research we care to electrical equipment for generation power plants which are generators and transformers.
Synchronous generator use in electric power plants for producing electric energy is very important element and much expensive so it should be provided with fully protection system to protect it against any abnormal conditions.
Power transformer is an electrical device that is used to change an alternating current and voltage from one electric circuit to another through electromagnetic induction.
A major application of transformers is to increase voltage before transmitting electrical energy over long distances through wires. Wires have resistance and so dissipate electrical energy at a rate proportional to the square of the current through the wire. By transforming electrical power to a high-voltage (and therefore low-current) form for transmission and back again afterward, transformers enable economic transmission of power over long distances. Consequently, transformers have shaped the electricity supply industry, permitting generation to be located remotely from points of demand. All but a tiny fraction of the world’s electrical power has passed through a series of transformers by the time it reaches the consumer transformers are also used extensively in electronic products to step down the supply voltage to a level suitable for the low voltage circuits they contain. The transformer also electrically isolates the end user from contact with the supply voltage.
Power transformers are no less important than generator in addition to it is expensive too, transformer must be provided by full protection system to avoid transformer failure. Transformer failure causes wasting of electric power especially transformer in electric power plants which has a very high rating.
Failure can occur in a generator or transformer due to different reasons and protection system prevent affected of protected equipment by external faults in addition to prevent evolving damage in case of internal faults leading to repair equipment rather than replace it.
In this report, three case studies are introduced to illustrate the importance of protection system in generation power plants, which are as follows:
1. The generator which belongs to Kafer EI-Dawar Power Station ,unit number 3, rated 137.5 MVA, IO.5kV. Improper synchronizing causes vibrations occur on generator bearings. Vibrations, which are considered simple, lead to line to line fault inside the generator that caused damage for a major part of stator coils. Fast trip generator by differential protection prevented evolving problem .Generator has been repaired instead of being replaced it and that will be explained in details in chapter 7.
2. The auxiliary transformer belong to Abu Qir Power Station, unit number 2, rated 15 MV A, 15/6.4 kV, delta / star was exploded because of internal short circuit and that will be explained in details in chapter 7.
3. The transformer in Damanhur Power Station failed after 10 years from its first energizing which is considered unacceptable because of its life span about (30-40) years and that will be explained in details in chapter 7.
This study aims to help us understand most advanced and important protection system for generator and transformer wqich is very important and expensive equipment to protect them from any repeated fault or expected fault in new researches which achieve stability of the power generation plants in addition to increasing efficiency in electric power generation sector.