Speed Control Methods Of DC Motor
DC motors brought us revolutionary changes in industrial and domestic applications.This all because of an unique feature of DC motors i.e, speed controlling of DC motors .Compared to Synchronous motor , Induction Motor controlling the speed of DC series or DC shunt motor is very easy and efficient. Now let's get into the detailed explanation on how we can control speed of DC motor ?
What is speed control?
Speed controlling is nothing but changing our DC motor speed according to our requirements.We have different methods to control speed.As we know DC motors are majorly categorized into DC series motors and DC shunt motors.
(where, P = no. of poles, Ø = flux/pole, N = speed in rpm, Z = no. ofarmature conductors, A = parallel paths)
Eb can also be given as,
Eb = V- IaRa
thus, from the above equations
N = Eb 60A/PØ
but, for a DC motor A, P and Z are constants
Therefore, N ∝ K Eb/Ø (where, K=constant)
This shows the speed of a dc motor is directly proportional to the back emf and inversely proportional to the flux per pole.
Speed Control Methods of a DC Motor
In DC motor an EMF induced in armature conductors due to the rotation of armature in magnetic field this is called back EMF (Eb). The magnitude of the Eb can be given by the EMF equation of a DC generator.
Eb = PØNZ/60A
Eb can also be given as,
Eb = V- IaRa
thus, from the above equations
N = Eb 60A/PØ
but, for a DC motor A, P and Z are constants
Therefore, N ∝ K Eb/Ø (where, K=constant)
This shows the speed of a dc motor is directly proportional to the back emf and inversely proportional to the flux per pole.
January 07, 2017 at 03:17PM by EEE, ADBU
