{"id":2908,"date":"2024-08-25T20:59:32","date_gmt":"2024-08-25T20:59:32","guid":{"rendered":"https:\/\/workhouse.sweetdishy.com\/?p=2908"},"modified":"2024-08-25T20:59:32","modified_gmt":"2024-08-25T20:59:32","slug":"rotor-emf","status":"publish","type":"post","link":"https:\/\/workhouse.sweetdishy.com\/index.php\/2024\/08\/25\/rotor-emf\/","title":{"rendered":"ROTOR EMF"},"content":{"rendered":"\n

The revolving magnetic field set up in the stator by polyphase currents is common to both stator and rotor winding. This field induces emfs in both windings. The stator-induced emf per phase is given by the relation<\/p>\n\n\n\n

 <\/p>\n\n\n\n

E<\/em>1<\/sub> = 4.44 \u00d7 kw<\/em>1<\/sub> \u00d7 T<\/em>1<\/sub> \u00d7 f <\/em>\u00d7 \u0278<\/em>m<\/sub>        (12.1)<\/p>\n\n\n\n

Where kw<\/em>1<\/sub> = winding factor, that is, product or coil span factor k<\/em>c<\/sub> and distribution factor k<\/em>d<\/sub>.<\/p>\n\n\n\n

T<\/em>1<\/sub> = No. of turns\/phase of stator winding<\/p>\n\n\n\n

\u0192<\/em>= stator or supply frequency and<\/p>\n\n\n\n

\u0278<\/em>m<\/sub>= maximum value of flux.<\/p>\n\n\n\n

The rotor-induced emf\/phase, E<\/em>2<\/sub> = 4.44 \u00d7 kw<\/em>2<\/sub> \u00d7 T<\/em>2<\/sub>\u00d7 \u0192<\/em>r<\/sub> \u00d7 \u0278<\/em>m<\/sub>        (12.2)<\/p>\n\n\n\n

Where \u0192<\/em>r<\/sub> is the rotor current frequency, and under stationary condition, that is, at the start \u0192<\/em>r<\/sub>= \u0192<\/em>.<\/p>\n\n\n\n

Therefore, rotor-induced emf\/phase at standstill or start, E<\/em>2s<\/sub>= 4.44 \u00d7 kw<\/em>2<\/sub> \u00d7 T<\/em>2<\/sub> \u00d7 f <\/em>\u00d7 \u0278<\/em>m<\/sub><\/p>\n\n\n\n

Dividing\u00a0equation (12.2)\u00a0by\u00a0(12.1), we get,<\/p>\n\n\n\n

\"image\" (i.e., transformation ratio)<\/p>\n\n\n\n

From\u00a0equation (12.2), induced emf in the rotor under running condition,<\/p>\n\n\n\n

 <\/p>\n\n\n\n

E<\/em>2<\/sub> = 4.44 \u00d7 kw<\/em>2<\/sub> \u00d7 T<\/em>2<\/sub> \u00d7 (S <\/em>\u00d7 f <\/em>) \u00d7 \u0278<\/em>m<\/sub> = S<\/em> \u00d7 E<\/em>2s<\/sub><\/p>\n\n\n\n

The induced emf in the rotor circuit is maximum at the start and varies according to the value of slip under running condition. Since the value of normal slip under loaded condition is nearly 5 per cent, the rotor-induced emf is, therefore, nearly 5 per cent of the maximum value.<\/p>\n","protected":false},"excerpt":{"rendered":"

The revolving magnetic field set up in the stator by polyphase currents is common to both stator and rotor winding. This field induces emfs in both windings. The stator-induced emf per phase is given by the relation   E1 = 4.44 \u00d7 kw1 \u00d7 T1 \u00d7 f \u00d7 \u0278m        (12.1) Where kw1 = winding factor, that is, product or coil span factor kc and distribution factor kd. T1 = No. […]<\/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-2908","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\/2908","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=2908"}],"version-history":[{"count":1,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/2908\/revisions"}],"predecessor-version":[{"id":2909,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/2908\/revisions\/2909"}],"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=2908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/categories?post=2908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/tags?post=2908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}