Contents
What is armature current?
In electrical engineering, an armature is the component of an electric machine that carries windings which, when an electric current passes, produces an electromotive force. The first is to carry current across the field, thus creating shaft torque in a rotating machine or force in a linear machine.
What is the difference between field current and armature current?
The current in the field does not alternate. The armature winding is that which generates or has an alternating voltage applied to it. The armature is the winding to which the load is connected. In small generators, the field windings are often on the stator, and the armature windings are on the rotor.
How do you calculate armature current?
Therefore, Average armature current, Motor emf, Ia=196.01−804=23.003AEa=Km. ωm=Km2π×140060Km=80×602π×1400=0.546V−s/rador 0.546Nm/A.
How can armature current be reduced?
How to Reduce Armature reaction in DC Machine
- The armature reaction causes the distortion in main field flux.
- If reluctance at pole tips is increased it will reduce distorting effect of armature reaction.
- The effect of armature reaction can be neutralized by use of compensating winding.
What is the difference between armature and commutator?
An armature is a combination of the winding, commutator, brushes, and ball bearings….What is Commutator?
| Armature | Commutator |
|---|---|
| It receives current from the armature windings | It receives current from the armature core |
| The core consists of armature windings, commutator, and brushes | It has some segments |
What is the advantage of armature?
1) The current is drawn directly from fixed terminals on the stator without the use of brush contacts. 2) The insulation of stationary armature winding is easier. 3) The number of sliding contacts (slip rings) is reduced. Moreover, the sliding contacts are used for low-voltage DC Source.
Why DC is used for excitation?
Why only D.C is used for Excitation in Alternators? Excitation voltage or current is supplied to the field windings of a rotor to produce a static magnetic field. If we use alternating current instead of direct current; we will get a fluctuating magnetic field.
What is armature rewinding?
Armature Winding is the winding, in which voltage is induced. Field Winding is the winding in which the main field flux is produced when the current through the winding is passed.
What is the armature resistance?
[′är·mə‚chər ri′zis·təns] (electricity) The ohmic resistance in the main current-carrying windings of an electric generator or motor.
What is field current?
: the current supplied to the field windings of a generator or motor to establish the magnetic field for its operation.
Which motor is used for blowers?
Induction motors — or (in the context of blowers in particular) often called by the more playful squirrel-cage motors (to avoid confusion with inducer-blower products). In fact, these motors are the most common used in blowers today, as they excel in high-horsepower blower and cooling-fan applications.
What is the main effect of armature reaction?
The adverse effects of armature reaction: Armature reaction weakens the main flux. In case of a dc generator, weakening of the main flux reduces the generated voltage. Armature reaction distorts the main flux, hence the position of M.N.A. gets shifted (M.N.A. is perpendicular to the flux lines of main field flux).
What happens when a conductor is mounted on an armature?
When a conductor carrying a current lies in a magnetic field, a force is exerted on the conductor and if this conductor be mounted on an armature which is free to rotate, rotation will occur. The commutator of a d.c. motor ensures that the conductors are always carrying currents so that torque production is maintained in the required direction.
How does an armature in a can work?
‘In a regular can motor, the armature spins inside the can when an electric current is applied.’ ‘The company also manufactures photovoltaic cells (used in the production of solar energy) and precision metal and plastic components such as gears, switches and motor armatures.’
What is the effect of the armature reaction?
This m.m.f. sets up a magnetic flux and the effect of this flux on that set up by the main poles is called armature reaction. The armature m.m.f. is acting on a relatively small airgap under the main poles and on a long air path of high reluctance between the poles.
How is the armature set up under the Poles?
Under the poles, the flux set up by the armature m.m.f. will be proportional to the m.m.f. but between the poles, the flux set up will be quite small even though the m.m.f. is greatest in this region. Neglecting magnetic saturation, the resultant flux distribution is found by adding the two separate fluxes.