![\"Equal](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2025\/02\/equal_area.jpg\")
<\/p>\nFor single machine system and infinite bus-bars a method known as \u201cequal area criterion of stability\u201d is employed. This method of stability study eliminates the calculations of swing curves which saves a considerable amount of work. This method is not applicable to multi-machine system and is applicable to only a single machine connected to infinite bus.<\/p>\n
The principle of equal area criteria consists of the basis that when \u03b4 oscillates around the equilibrium point with constant amplitude, transient stability will be maintained.<\/p>\n
Consider the swing equation,<\/p>\n
<\/p>\n
If the system is unstable \u03b4 continues to increase with respect to time and the machine losses synchronism. On the other hand, if the system is stable, \u03b4(t) performs oscillations whose amplitude decreases in actual practice because of damping terms. These situations are shown below in figure.<\/p>\n
![\"Damping\"](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2025\/02\/damping.jpg\")
<\/p>\n
Practically, the response \u03b4(t) in a power system generally falls in the two broad categories as shown above in figure. For a stable system, in the first swing, \u03b4 goes to a maximum and starts to reduce.
\nHence, the system is stable if at some time d\u03b4\/dt = 0 and the system is unstable if at some time d\u03b4\/dt > 0 (generally t\u00a0 > 1 sec).![\"Plot\"](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2025\/02\/plot.jpg\")
<\/p>\n
Conclusion<\/strong><\/p>\n Equation (3) indicates that the system is stable if the area under Pa (accelerating power) \u2013 \u03b4 curve reduces to zero at some value of \u03b4. In other words, for the system to be stable, during transient the positive area (accelerating area) under Pa – \u03b4 curve must be equal to the negative area (decelerating area) and hence the name \u201cequal-area\u201d criterion of stability.<\/p>\n << Previous<\/a> | Next >><\/a> For single machine system and infinite bus-bars a method known as \u201cequal area criterion of stability\u201d is employed. This method<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1221,5],"tags":[1254,400,1253,1251],"class_list":["post-4359","post","type-post","status-publish","format-standard","hentry","category-power-generation-concepts","category-ee","tag-accelerating-power","tag-equilibrium","tag-swing-curves","tag-transient-stability"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/4359","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=4359"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/4359\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=4359"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=4359"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=4359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n Must Read: <\/strong> What is Power Generation?<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"