{"id":4909,"date":"2024-08-20T19:03:48","date_gmt":"2024-08-20T19:03:48","guid":{"rendered":"https:\/\/svestudy.com\/?page_id=4909"},"modified":"2025-05-11T11:10:39","modified_gmt":"2025-05-11T11:10:39","slug":"aux-1-unit-15-q8","status":"publish","type":"page","link":"https:\/\/svestudy.com\/?page_id=4909","title":{"rendered":"Aux 1 Unit 15 Q8"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"114\" src=\"https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166-1024x114.png\" alt=\"\" class=\"wp-image-5769\" srcset=\"https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166-1024x114.png 1024w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166-300x33.png 300w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166-768x85.png 768w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166-1200x133.png 1200w, https:\/\/svestudy.com\/wp-content\/uploads\/2024\/08\/image-166.png 1478w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">(a) Describe the construction of a salient pole a.c. generator rotor.(6)<br>(b) Explain how many poles would be required for a 50Hz supply, rotational speed of 750rpm.(4)<\/p>\n\n\n<div class=\"wp-block-ub-content-toggle wp-block-ub-content-toggle-block\" id=\"ub-content-toggle-block-ce549d91-408b-4415-b753-d88a258cdd9a\" data-mobilecollapse=\"true\" data-desktopcollapse=\"true\" data-preventcollapse=\"false\" data-showonlyone=\"false\">\n<div class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; \" id=\"ub-content-toggle-panel-block-d2383d44-c6b6-48fe-acd2-ebbf9bc7ecb2\">\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-0-ce549d91-408b-4415-b753-d88a258cdd9a\" tabindex=\"0\">\n\t\t\t<p class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-ce549d91-408b-4415-b753-d88a258cdd9a\" style=\"color: #000000; \">The construction of a salient pole a.c. generator rotor.<\/p>\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"><span class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"><\/span><\/div>\n\t\t<\/div>\n\t\t\t<div role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-0-ce549d91-408b-4415-b753-d88a258cdd9a\">\n\n<p class=\"wp-block-paragraph\">Let&#8217;s break down the construction of a salient pole AC generator rotor:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Core Structure:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Laminated Steel:<\/strong> The rotor core is built from a stack of thin silicon steel laminations, each insulated from the others to minimize eddy current losses. These laminations are typically 0.5mm to 1.5mm thick. \u00a0 <a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\">1. US9205487B2 &#8211; Compensation mechanism for cast rotor lamination stack height and compression pressure control &#8211; Google Patents <\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\">patents.google.com<\/a><a href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Shaft:<\/strong> A central shaft made of high-strength steel runs through the core, providing the axis of rotation for the rotor.<\/li>\n\n\n\n<li class=\"\"><strong>Spider:<\/strong> In large rotors, a spider, also made of steel, is used to support the laminated core and provide structural integrity.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Salient Poles:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Projections:<\/strong> The defining feature of this rotor type is the presence of salient poles \u2013 distinct, projecting pole pieces that extend outward from the rotor core.<\/li>\n\n\n\n<li class=\"\"><strong>Number of Poles:<\/strong> The number of poles depends on the desired generator speed and frequency. Slower-speed generators typically have more poles.<\/li>\n\n\n\n<li class=\"\"><strong>Pole Construction:<\/strong>\n<ul class=\"wp-block-list\">\n<li class=\"\">Laminated Core: Each pole is also constructed from laminated silicon steel to reduce eddy current losses.<\/li>\n\n\n\n<li class=\"\">Pole Shoe: The outer end of each pole is often fitted with a pole shoe, which helps shape the magnetic field and improve the generator&#8217;s efficiency.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Field Windings:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Excitation Coils:<\/strong> Insulated copper conductors are wound around each pole to form the field windings or excitation coils.<\/li>\n\n\n\n<li class=\"\"><strong>DC Excitation:<\/strong> These coils are supplied with DC current, creating a strong magnetic field around each pole.<\/li>\n\n\n\n<li class=\"\"><strong>Connection:<\/strong> The field windings are connected in series, and the ends are brought out to slip rings mounted on the shaft.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Slip Rings and Brushes:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Electrical Connection:<\/strong> Slip rings provide a continuous electrical connection between the rotating field windings and the stationary external DC excitation source. \u00a0 <a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\">1. What&#8217;s the role of the slip ring in generators? &#8211; TutorChase <\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\">www.tutorchase.com<\/a><a href=\"https:\/\/www.tutorchase.com\/answers\/ib\/physics\/what-s-the-role-of-the-slip-ring-in-generators#:~:text=The%20slip%20ring%20rotates%20with,coil%20and%20the%20stationary%20external\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Carbon Brushes:<\/strong> Carbon brushes press against the slip rings, conducting the DC current to the field windings. \u00a0 <a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Carbon brush performance on slip rings &#8211; ResearchGate <\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\">www.researchgate.net<\/a><a href=\"https:\/\/www.researchgate.net\/publication\/261451556_Carbon_brush_performance_on_slip_rings#:~:text=in%20traction%20motors.-,...,excitation%20to%20the%20field%20winding.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Other Features:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Damper Windings (Amortisseur Windings):<\/strong> These short-circuited copper bars are often embedded in the pole faces to help dampen oscillations and improve stability during transient conditions.<\/li>\n\n\n\n<li class=\"\"><strong>Cooling:<\/strong> Depending on the size and design, the rotor might have internal cooling channels or fans to dissipate heat generated in the windings.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key Points:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Non-Uniform Air Gap:<\/strong> The air gap between the rotor poles and the stator is non-uniform, being smaller at the pole centers and larger between the poles. This creates a varying reluctance path that helps generate a sinusoidal output voltage.<\/li>\n\n\n\n<li class=\"\"><strong>Suitable for Low and Medium Speeds:<\/strong> Salient pole rotors are typically used in generators designed for low to medium speeds, such as those driven by hydroelectric turbines or diesel engines.<\/li>\n\n\n\n<li class=\"\"><strong>Rugged Construction:<\/strong> Their robust construction makes them suitable for handling high mechanical stresses and large power outputs.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In summary:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The salient pole AC generator rotor consists of a laminated steel core with projecting poles, each wound with excitation coils. The rotating magnetic field created by these poles interacts with the stator winding to generate electricity. This type of rotor is characterized by its non-uniform air gap and suitability for low to medium speed applications. \u00a0<a href=\"https:\/\/testbook.com\/question-answer\/the-salient-pole-type-construction-is-suitable-for--637eebe4d2cfc0687b7bee02\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/testbook.com\/question-answer\/the-salient-pole-type-construction-is-suitable-for--637eebe4d2cfc0687b7bee02\" target=\"_blank\" rel=\"noreferrer noopener\">1. [Solved] The salient pole type construction is suitable for running l &#8211; Testbook <\/a><a href=\"https:\/\/testbook.com\/question-answer\/the-salient-pole-type-construction-is-suitable-for--637eebe4d2cfc0687b7bee02\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/testbook.com\/question-answer\/the-salient-pole-type-construction-is-suitable-for--637eebe4d2cfc0687b7bee02\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a target=\"_blank\" rel=\"noreferrer noopener\" href=\"https:\/\/patents.google.com\/patent\/US9205487B2\/en\"><\/a><\/p>\n\n<\/div>\n\t\t<\/div>\n\n<div class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-left-radius: 8px; border-bottom-right-radius: 8px; \" id=\"ub-content-toggle-panel-block-d2383d44-c6b6-48fe-acd2-ebbf9bc7ecb2\">\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-1-ce549d91-408b-4415-b753-d88a258cdd9a\" tabindex=\"0\">\n\t\t\t<p class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-ce549d91-408b-4415-b753-d88a258cdd9a\" style=\"color: #000000; \">How many poles would be required for a 50Hz supply, rotational speed of 750rpm?<\/p>\n\t\t\t<div class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"><span class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"><\/span><\/div>\n\t\t<\/div>\n\t\t\t<div role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-1-ce549d91-408b-4415-b753-d88a258cdd9a\">\n\n<p class=\"wp-block-paragraph\">The number of poles required for a 50 Hz supply and a rotational speed of 750 rpm is <strong>8<\/strong>. \u00a0<a href=\"https:\/\/testbook.com\/question-answer\/an-8-pole-3-phase-50-hz-induction-motor-is-opera--61ceb52b7505e824293d0a48\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/testbook.com\/question-answer\/an-8-pole-3-phase-50-hz-induction-motor-is-opera--61ceb52b7505e824293d0a48\" target=\"_blank\" rel=\"noreferrer noopener\">1. [Solved] An 8-pole, 3-phase, 50 Hz induction motor is operating at 72 &#8211; Testbook <\/a><a href=\"https:\/\/testbook.com\/question-answer\/an-8-pole-3-phase-50-hz-induction-motor-is-opera--61ceb52b7505e824293d0a48\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/testbook.com\/question-answer\/an-8-pole-3-phase-50-hz-induction-motor-is-opera--61ceb52b7505e824293d0a48\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Here&#8217;s the explanation:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Synchronous Speed:<\/strong> In AC motors and generators, the synchronous speed (the speed of the rotating magnetic field) is determined by the supply frequency and the number of poles. The formula is: \u00a0 <a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\">1. Rotating Magnetic Fields &amp; AC Motor Operation &#8211; WorldWide Electric Corporation <\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\">worldwideelectric.com<\/a><a href=\"https:\/\/worldwideelectric.com\/articles\/rotating-magnetic-fields-ac-motor-operation\/#:~:text=It%20is%20known%20as%20%E2%80%9Csynchronous,number%20of%20poles%20(P).\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><code>Ns = (120 * f) \/ P<\/code> where:\n<ul class=\"wp-block-list\">\n<li class=\"\">Ns = Synchronous speed in revolutions per minute (RPM) \u00a0 <a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\">1. Technology Support &#8211; LUYANG <\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\">www.luyangmotor.com<\/a><a href=\"https:\/\/www.luyangmotor.com\/msg\/technology-support.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\">f = Supply frequency in Hertz (Hz)<\/li>\n\n\n\n<li class=\"\">P = Number of poles<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li class=\"\"><strong>Actual Speed:<\/strong> The actual rotational speed of an induction motor is slightly lower than the synchronous speed due to slip. However, for this calculation, we&#8217;ll consider the synchronous speed as the desired rotational speed. \u00a0 <a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\">1. Induction Motors and Slip Speed \u2014 Lesson 7 &#8211; Ansys Customer Center <\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\">innovationspace.ansys.com<\/a><a href=\"https:\/\/innovationspace.ansys.com\/courses\/courses\/rotating-magnetic-fields-and-motors\/lessons\/induction-motors-and-slip-speed-lesson-7\/#:~:text=%2D%20In%20the%20presence%20of%20opposing,less%20than%20the%20synchronous%20speed.\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/li>\n\n\n\n<li class=\"\"><strong>Calculation:<\/strong>\n<ol class=\"wp-block-list\">\n<li class=\"\">We know the desired frequency (f = 50 Hz) and rotational speed (n = 750 rpm).<\/li>\n\n\n\n<li class=\"\">We need to find the number of poles (P).<\/li>\n\n\n\n<li class=\"\">Rearranging the formula, we get: <code>P = (120 * f) \/ Ns<\/code><\/li>\n\n\n\n<li class=\"\">Plugging in the values: <code>P = (120 * 50) \/ 750 P = 6000 \/ 750 P = 8<\/code><\/li>\n<\/ol>\n<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Therefore, an 8-pole AC generator or motor is needed to achieve a rotational speed of 750 rpm when connected to a 50 Hz power supply.<\/strong><\/p>\n\n<\/div>\n\t\t<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>(a) Describe the construction of a salient pole a.c. generator rotor.(6)(b) Explain how many poles would be required for a 50Hz supply, rotational speed of 750rpm.(4)<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"templates\/template-full-width.php","meta":{"nf_dc_page":"","footnotes":""},"class_list":["post-4909","page","type-page","status-publish","hentry"],"featured_image_src":null,"_links":{"self":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/4909","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/svestudy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4909"}],"version-history":[{"count":3,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/4909\/revisions"}],"predecessor-version":[{"id":9519,"href":"https:\/\/svestudy.com\/index.php?rest_route=\/wp\/v2\/pages\/4909\/revisions\/9519"}],"wp:attachment":[{"href":"https:\/\/svestudy.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4909"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}