Why a DC shunt motor is also called a constant flux motor or constant speed motor?

Detailed Solution. In case of DC shunt motor, flux is practically constant as the field is parallel to the armature. If the load is increased, then the speed of the motor will remain almost constant because the field current remains almost constant. So that it is also known as constant speed motor.

Why a DC shunt motor is also called a constant flux motor or constant speed motor name any three applications of DC shunt motors?

In a shunt motor, the shunt field current Ish is always a constant since the field winding is connected in parallel to the armature winding and the supply voltage. If load change is not considered since a DC shunt motor has a constant flux φ and a constant supply voltage the speed of the motor remains constant.

Is flux constant in separately excited DC motor?

Operating Characteristics of a Separately Excited DC Motor Thus, these two motors have identical speed-armature current and torque–armature current features. In a separately excited DC motor, the flux is assumed to be constant.

Which of the following is constant flux DC motor?

In dc shunt motor flux produced by field winding is proportional to field current. Here the input voltage is constant so field current and flux is also constant. So dc shunt motor is also called a constant flux or constant speed motor. Hence the speed of DC shunt motor is independent of armature current.

What is constant in DC shunt motor?

In case of DC shunt motor, the shunt field current is always constant. Since the field winding is connected in parallel to the armature winding and the supply voltage under a constant supply voltage and normal load, then the field flux of the shunt motor remain approximately same.

Which motor is a constant speed motor Why?

The slip of the induction motor varies in between 3 to 5 \% of the synchronous speed. When the load on induction is increased,the slip gets decreased within its specified slip range. Thus, an induction motor can be called as a constant speed motor. Why Three Phase Induction Motor Self-Starting?

Why is the flux practically constant in separately excited generator?

Separately Excited DC Generator The flux produced by the poles depends upon the field current with the unsaturated region of magnetic material of the poles. i.e. flux is directly proportional to the field current. But in the saturated region, the flux remains constant.

What is the principal difference between a separately excited shunt and shunt dc motor?

A separately excited dc motor is a motor whose field circuit is supplied from a separate constant-voltage power supply, while a shunt dc motor is a motor whose field circuit gets its power directly across the armature terminals of the motor.

Which losses of DC shunt motor are constant?

The core losses are the hysteresis and eddy current losses. These losses are considered almost constant as the machines are usually operated at constant flux density and constant speed.

Which is constant speed motor?

A DC motor can be referred to as a constant speed motor because it can self- regulate its speed.

Why synchronous motor is a constant speed motor?

Synchronous motor is the motor when rotor speed synchronise with speed of rotating magnetic field. Rotor speed of synchronous motor locked with the speed Rotating magnetic field. So the speed of synchronous motor must be constant and fixed. This speed solely depends upon frequency and no of poles.