ABSTRACT
Power system control has traditionally been accomplished by entities in “control areas.” The “control area” concept involves balancing load with generation within the electrical boundaries corresponding to the service territory of a vertically integrated utility. When the amount of generation in a control area exceeds the total load within a control area, frequency will increase. As long as electric power service is reliable, most people are content and unconcerned about pursuing the subject of reliability. The general level of interest in reliability peaks when electric power service is unreliable. Within the field of power system reliability analysis there are well- established methods for analyzing and calculating component and system reliability. At the power distribution system level, a number of indices have been defined for assessing reliability. The North American Electric Reliability Council used the following definitions of power system reliability and power system security during the 1980s and 1990s.
