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Prepared by
Eng \ Mohamed Mamdouh Kabsha


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INTRODUCTION:

Power system is the backbone of the life that nobody can do without it and power system represents the country it belong to as the more the country developing the more the system stronger and reliable is, so any country that want to keep up with the international development and convenience of the society it must take care of making the power system stable, secure and reliable and form this point of view this paper offered a discussion of possible root causes of blackout and necessary steps to reduce the risk of it, the ways of right investment to improve system stability. Also represent the major methods of restoration approaches.
Blackout has a significant effect on the society so it is a disaster so when a blackout occur the first thing considered is trying to restore the electric power to the important load until there will be not any load without power in minimum time in order to minimize the loss. Blackouts are of different type and the worst one is the total blackout type that spread along wide area through a single country or more this will be viewed later.
blackout occur due to various events that may be unexpected events such as weather ,maintenance outage and tree growth and since securing the power system against all possible contingencies and dangerous events is clearly impossible so the fundamental principle only calls for securing against all credible contingencies. If the rules of operation were followed then blackout will then occur only if contingencies that were not considered credible occurred.
The complete prevent of blackout is difficult for long time but it's probability should be decreased through good design of power system network component and protect it by intelligent protection system that work properly when needed and don't operate unnecessarily. Also the rules of operation must be followed and after do all that the blackout can also occur.

Overview of the Electric Power System and Its Reliability

Modern society has come to depend on reliable electricity as an essential resource for national security; health and welfare; communications; finance; transportation; food and water supply;
heating, cooling, and lighting; computers and electronics; commercial enterprise; and even entertainment and leisure in short, nearly all aspects of modern life. Customers have grown to expect that electricity will almost always be available when needed at the flick of a switch. Most customers have also experienced local outages caused by a car hitting a power pole, a construction crew accidentally damaging a cable, or a lightning storm. What is not expected is the occurrence of a massive outage on a calm, warm day. Widespread electrical outages, such as the one that occurred on August 14, 2003 USA-Canada, are rare, but they can happen if multiple reliability safeguards break down.
Providing reliable electricity is an enormously complex technical challenge, even on the most routine of days. It involves real-time assessment, control and coordination of electricity production at thousands of generators, moving electricity across an interconnected network of transmission lines, and ultimately delivering the electricity to millions of customers by means of a distribution network.
As shown in Figure 2.1, electricity is produced at lower voltages (10,000 to 25,000 volts) at generators from various fuel sources, such as nuclear, coal, oil, natural gas, hydro power, geothermal, photovoltaic, etc. Some generators are owned by the same electric utilities that serve the end-use customer; some are owned by independent power producers (IPPs); and others are owned by customers themselves particularly large industrial customers.

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