In ac machines, why is the stator winding for phase-b placed 120 degree ahead of phase-a whereas the phasors for phase-b (such as Vb) lag behind the corresponding phasors for phase-a ?

Asked by Last Modified  

8 Answers

Follow 0
Answer

Please enter your answer

electrical

Dear fairooz, I don't now with reference to what u are asking. in case of generator, rotor rotates and as the field windings are on rotor, field is said to be rotating or rotating magnetic field. since the flux cuts the stationary conductors emf is induced in the stationary windings.and...
read more
Dear fairooz, I don't now with reference to what u are asking. in case of generator, rotor rotates and as the field windings are on rotor, field is said to be rotating or rotating magnetic field. since the flux cuts the stationary conductors emf is induced in the stationary windings.and emf phase sequence depends on how 3 phase windings are placed.if they are 120 degree apart then only it satisfies a 3 phase system otherwise it is not.leading or lagging of phasors depend on field rotation (if field is rotating) .in case of synchronus motor if we give 3 phase balanced supply rmf produced in stator if and only iff windinds are pl aced in 120 apart otherwise not.stator field is now rotating but rotor flux is stationary.so no motion of rotor in synchronus motor. read less
Comments

I have very good subject knowledge in all the electrical subjects..i can cover to gate level.. And i can teach mathematics and java too.

Basic concept in polypahse AC machine is to generate RMF. The rmf can be developed in any machine except single pahse machine . if you increase the no of pahses strength of the rmf will increase but there more advantage if you use for 3 phase system instead of 2phase system.. As compared to other ez...
read more
Basic concept in polypahse AC machine is to generate RMF. The rmf can be developed in any machine except single pahse machine . if you increase the no of pahses strength of the rmf will increase but there more advantage if you use for 3 phase system instead of 2phase system.. As compared to other ez 4,5 phase system strength of rmf increase but very less value .. That requires details derivation... The steangth of rmf decides the stator rmf which will incfluence the rotor rmf ie speed of rotor .. So from the advantage of 3 phase system compared to other phase system the widings in eachpahse are diaplced 360/3 = 120 degress .. Let me know if you have more doubts? read less
Comments

Tutor

It is all reference system. Its like if you are seeing rotor from outside then if you watching it moving clockwise. Then if we imagine you are standing on rotor, then u ll feel the surroundings are moving anticlockwise, think in this context. IT is what happens in actual.
Comments

In ac machine, rotating magnetic field (rmf) is required. By using 3 phase ie 120 degree displacement rmf is produced. now, we place Va-Vb-Vc in this sequence because Va start from zero.
Comments

Electrical Engineering ,gate

Its not always necessary that phase b is lag...it is just an examples we saw in books...for machines to rotate there should always a condition...that it rotates from leading axis to lagging axis.....
Comments

What you are saying about laging behind is a 3 ph voltage .. one phase voltage lags the other bt 120.. and physically windings are kept 120 apart to produce rmf.. Dont confuse with mechanical design and 3 phase supply
Comments

Student's Badhsha

in order to produce rotating magnetic filed b/w rotar and stator
Comments

Electrical Enthusiastic

to produce a constant rotating magnetic flux the manufacturer designed with 120 degrees phase shift
Comments

View 6 more Answers

Related Questions

How should I do self-study of chemistry class 12 without any coaching to get a perfect score?
first you should know all the basic concepts and practise it . and watch youtube videos which is related to topics. it is more than enough to get a decent score. And also refer the old Model Question Papers.
Aditya
0 0
5
Hi, how would I get students to teach?
Best Way to get Students on UrbanPro is , Better Become the Silver Member by Purchasing nearly 500 rs for first 3 months. Then you will be easily getting the Numbers of the Customers/Students According...
S.ataurehman
Should I join a coaching institute in the 11th class or do self-study?
There two factors in this: 1. Why do you think you should join coaching? Let me reframe- Do you think you need coaching? What do you intend to achieve form it? 2. What are your subjects? If you are studying...
Gene
0 0
8

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Data Sorting In Excel
Sorting data in MS Excel rearranges the rows based on the contents of a particular column. You may want to sort a table to put names in alphabetical order. Or, maybe you want to sort data by Amount from...

Types of Open Channel Flow
Types of Open Channel Flow 1 Steady Flow Flow is said to be steady when discharge does not change along the course of the channel flow. 2 Unsteady Flow Flow is said to be steady when discharge changes...

Digital Multimeter
• DMM is a measuring instrument • An ammeter measures current • A voltmeter measures the potential difference (voltage) between two points • An ohmmeter measures resistance •...


Reheater in a steam power plant
Which combination of the following statements is correct ?The incorporation of reheater in a steam power plant:P : always increases the thermal efficiency of the plant.Q : always increases the dryness...

Recommended Articles

MBA, Medicine and engineering are the three main professional courses in India. Engineering is still one of the highly sorted after professional courses in the under graduate level, while MBA is favoured as a preferred post graduate course. To shine in these courses, one needs to work and study hard. Engineering as a...

Read full article >

According to a recent survey conducted by the NCAER (National Council of Advanced Economic Research), engineering is the most sought after course in India. Some engineering courses are offered as BE or Bachelor of Engineering while some as Bachelor in Technology or B.Tech. Since engineering is a professional course, the...

Read full article >

Once over with the tenth board exams, a heavy percentage of students remain confused between the three academic streams they have to choose from - science, arts or commerce. Some are confident enough to take a call on this much in advance. But there is no worry if as a student you take time to make choice between - science,...

Read full article >

E-learning is not just about delivering lessons online. It has a much broader scope that goes beyond manual paper or PowerPoint Presentations. To understand the reach of E-learning and how the whole process works in developing the Educational system, we will discuss a few points here. Let us find out how this new learning...

Read full article >

Looking for BTech Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you