What is Speed Regulation of DC Motor?

What is Speed Regulation of DC Motor?

Speed regulation definition

The speed regulation of a DC motor is a change in speed from no-load to full load, expressed as a fraction or percentage of full load speed.

Good speed regulation

A motor with good speed regulation has the smallest difference between no-load and full-load speeds.

Motor type

• Permanent magnet dc motor

• Dc shunt motor

• Dc series motor

• Compound dc motor

Velocity and electromotive force relation

The speed of a DC motor is proportional to the electromotive force (emf) and inversely proportional to the magnetic flux per pole.

Here,

N = speed of rotation in rpm.

P = number of poles.

A = number of parallel paths.

Z = total no. conductors in armature.

Therefore, the speed of a DC motor is directly proportional to the electromotive force (emf) and inversely proportional to the flux per pole (φ).

Speed regulation formula

Speed regulation is calculated using a specific formula that takes into account the no-load and full-load speeds.

Speed regulation is defined as the change in speed from no load to full load, expressed as a fraction or percentage of full-load speed.

Therefore, as per definition per unit (p.u) speed regulation of DC motor is given as,

Similarly, percentage (%) speed regulation is given as,

Where,

Therefore,

A motor that maintains nearly constant speed at all loads below full rated load has good speed regulation.