{"id":2896,"date":"2024-08-25T20:53:17","date_gmt":"2024-08-25T20:53:17","guid":{"rendered":"https:\/\/workhouse.sweetdishy.com\/?p=2896"},"modified":"2024-08-25T20:53:18","modified_gmt":"2024-08-25T20:53:18","slug":"production-of-revolving-field","status":"publish","type":"post","link":"https:\/\/workhouse.sweetdishy.com\/index.php\/2024\/08\/25\/production-of-revolving-field\/","title":{"rendered":"PRODUCTION OF REVOLVING FIELD"},"content":{"rendered":"\n

Consider a stator on which three different windings represented by three concentric coils a<\/em>1<\/sub>a<\/em>2<\/sub>, b<\/em>1<\/sub>b<\/em>2<\/sub>, and c<\/em>1<\/sub>c<\/em>2<\/sub>, respectively, are placed 120\u00b0 electrically apart.<\/p>\n\n\n\n

Let a three-phase supply, as shown in\u00a0Figure 12.5, is applied to the stator. Three-phase currents will flow through the three coils and produce their own magnetic fields. The positive half\u00a0cycle of the alternating current (AC) is considered as inward flow of current in the start terminals and negative half cycle is considered as outward flow of current in the start terminals. The direction of flow of current is opposite in the finish terminals of the same coil.<\/p>\n\n\n\n

\"image\"\/<\/figure>\n\n\n\n

Fig. 12.5  <\/strong>Wave diagram of 3-phase AC supply with instants t1<\/sub>,t2<\/sub> and t3<\/sub><\/p>\n\n\n\n

Let at any instant\u00a0t<\/em>1<\/sub>, current in coil side\u00a0a<\/em>1<\/sub>\u00a0be inward and in\u00a0b<\/em>1<\/sub>\u00a0and\u00a0c<\/em>1<\/sub>\u00a0outward, whereas the current in the other sides of the same coils is opposite, that is,in coil side\u00a0a<\/em>2<\/sub>\u00a0is outward and\u00a0b<\/em>2<\/sub>\u00a0and\u00a0c<\/em>2<\/sub>\u00a0is inward. The resultant field and its direction (F<\/em>m<\/sub>) are marked in\u00a0Figure 12.6.<\/p>\n\n\n\n

At instant\u00a0t<\/em>2<\/sub>, when\u00a0\u03b8<\/em>\u00a0is 60\u00b0, current in coil sides\u00a0a<\/em>1<\/sub>\u00a0and\u00a0b<\/em>1<\/sub>\u00a0is inward and in\u00a0c<\/em>1<\/sub>\u00a0is outward, whereas the current in the opposite sides is opposite. The resultant field and its direction is shown in\u00a0Figure 12.7, which is rotated through an angle\u00a0\u03b8<\/em>\u00a0= 60\u00b0 from its previous position.<\/p>\n\n\n\n

At instant\u00a0t<\/em>3<\/sub>\u00a0when\u00a0\u03b8<\/em>\u00a0is 120\u00b0, current in coil side\u00a0b<\/em>1<\/sub>\u00a0is inward and in\u00a0c<\/em>1<\/sub>\u00a0and\u00a0a<\/em>1<\/sub>\u00a0is outward. The resultant field and its direction is shown in\u00a0Figure 12.8, which is rotated through an angle\u00a0\u03b8<\/em>\u00a0= 120\u00b0 electrical from its first position.<\/p>\n\n\n\n

\"image\"\/<\/figure>\n\n\n\n

Fig. 12.6  <\/strong>Position of resultant field at instant t1<\/sub><\/p>\n\n\n\n

Fig. 12.7  <\/strong>Position of resultant field at instant t2<\/sub><\/p>\n\n\n\n

Fig. 12.8  <\/strong>Position of resultant field at instant t3<\/sub><\/p>\n\n\n\n

Thus, in one cycle, the resultant field completes one revolution. Hence, we conclude that when three-phase supply is given to a three-phase wound stator, a resultant field is produced which revolves at a constant speed, called synchronous speed (N<\/em>s<\/sub> = 120\u00b0 f \/ P).<\/em><\/p>\n\n\n\n

In this case, we have observed that when supply from phase 1, 2, and 3 is given to coil a<\/em>1<\/sub>a<\/em>2<\/sub>, b<\/em>1<\/sub>b<\/em>2<\/sub>, and c<\/em>1<\/sub>c<\/em>2<\/sub>, respectively, an anticlockwise rotating field is produced. If the supply to coil a<\/em>1<\/sub>a<\/em>2<\/sub>, b<\/em>1<\/sub>b<\/em>2,<\/sub> and c<\/em>1<\/sub>c<\/em>2<\/sub> is given from phase 1, 3, and 2, respectively, the direction of rotating field is reversed. Therefore, to reverse the direction of rotation of rotating field, the connections of any two supply terminals are inter changed.<\/p>\n","protected":false},"excerpt":{"rendered":"

Consider a stator on which three different windings represented by three concentric coils a1a2, b1b2, and c1c2, respectively, are placed 120\u00b0 electrically apart. Let a three-phase supply, as shown in\u00a0Figure 12.5, is applied to the stator. Three-phase currents will flow through the three coils and produce their own magnetic fields. The positive half\u00a0cycle of the alternating current (AC) […]<\/p>\n","protected":false},"author":1,"featured_media":2894,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[415],"tags":[],"class_list":["post-2896","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-three-phase-induction-motors"],"jetpack_featured_media_url":"https:\/\/workhouse.sweetdishy.com\/wp-content\/uploads\/2024\/08\/spare-parts.png","_links":{"self":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/2896","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/comments?post=2896"}],"version-history":[{"count":1,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/2896\/revisions"}],"predecessor-version":[{"id":2897,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/2896\/revisions\/2897"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media\/2894"}],"wp:attachment":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media?parent=2896"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/categories?post=2896"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/tags?post=2896"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}