آخر الأخبار

جاري التحميل ...

  1. Thanks for sharing your thoughts. I truly appreciate your efforts and I am waiting for your next write ups thanks once again.

    Pauleen
    www.imarksweb.org

    ReplyDelete

Torque and Speed Equations

       Before analysing the various characteristics of motors, let us revise the torque and speed equations are applied to various types of motors.
...              T α Φ Ia from torque equation.
       This is because, 0.159(PZ)/A is a constant for a given motor.
       Now  Φ is the flux produced by the field winding and is proportional to the current passing through the field winding.
                   Φ α Ifield
       But for various types of motors, current through the field winding is different. Accordingly torque equation must be modified.
       For a d.c. shunt motor,  Ish is constant as long as supply voltage is constant. Hence Φ flux is also constant.
...              T α  Ia                 for shunt motors
       For a d.c. series motor,   Ise  is same as  Ia. Hence flux Φ is proportional to the armature current Ia.
...               α  Ia   α  Ia2                   for series motors.
Similarly as Eb   = (ΦPNZ)(60A), we can write the speed equation as,
                   Eb  α    Φ N 
...                 α  Eb
       But   V =  Eb   I Ra          neglecting brush drop
...             Eb   = V -  I Ra
...     Speed equation becomes,
                N   α (V-I Ra)/Φ
       So for shunt motor as flux is constant,
...              N   α   V - I Ra
       While for series motor, flux Φ is proportional to Ia.

       These relations play an important role in understanding the various characteristics of different types of motors.
1.1 Speed Regulation
       The speed regulation for a d.c. motor is defined as the ratio of change in speed corresponding to no load and full load condition to speed corresponding to full load.
       Mathematically it is expressed as,  
Related Articles :
Flux Control
Necessity of Starter for D.C. Motors
Four Point Starter
Parameters Magnets D.C. Motors

Sponsored links :

about author

hamada i'm hamada rageh electrical power engineer my talent to write articles about electrical engineering and i depend on google books site to write my articles

التعليقات


اتصل بنا

إذا أعجبك محتوى مدونتنا نتمنى البقاء على تواصل دائم ، فقط قم بإدخال بريدك الإلكتروني للإشتراك في بريد المدونة السريع ليصلك جديد المدونة أولاً بأول ، كما يمكنك إرسال رساله بالضغط على الزر المجاور ...

جميع الحقوق محفوظة

your electrical home