what is ac generator write the working and construction of AC generator
Answers
Explanation:
This is a machine that converts mechanical energy to electrical energy giving an output of alternating current or voltage. It works on the principle of faraday’s law of electromagnetic induction. The direction of current in an Alternating Current generator is found by using fleming’s right-hand rule. A four-pole single-phase generator is shown in 1st photo in the attachment.
Construction
It consists of Yoke, permanent magnets, a coil or loop wound with wires, pole core, armature core, pole shoe, slip rings, and brushes. The Yoke is a frame that acts as a protecting cover for the generator. All the components rest inside the Yoke. Magnets are used for the production of the magnetic field inside the air gap. A coil made of four-wire AB, BC, CD, and DC is placed inside the magnetic field. The schematic diagram of this machine is shown in the 2nd photo of the attachment below.
Pole core consists of pole shoe which is used to house the windings. The core of armature is used to rest the armature windings. The armature is responsible for the production of armature flux. The slip rings are used for the operation to be performed smoothly. These are attached to the brushes through the current passes. Slip rings run smoothly between the brushes which avoid the twisting of wires.
Working
It works on the principle of Faraday’s law of electromagnetic induction. Whenever a conductor cuts the lines of magnetic flux an EMF will be induced that causes the current to flow in the conductors. For a better understanding of the working of the Alternating Current Generator, consider a simple loop generator placed under the influence of a magnetic field. The loop placed inside the magnetic field is named as ABCD as this loop is an attachment of wire AB, BC, CD, and DC. This loop is rotated by using an external shaft which is generally a prime mover. The working of an Alternating Current Generator is shown in the 3rd photo in the attachment.
The lines of magnetic flux will be from left to right from Pole ‘N’ and ‘S’. When the loop is rotated it cuts the magnetic flux thus, developing an EMF. The developed EMF causes the current to flow in the conductors. This current direction is found by using fleming’s right-hand rule in generators.
Fleming’s right-hand rule states that the three fingers middle, fore-finger, and thumb are positioned perpendicular to each other. The representation of Fleming’s Right-hand rule is shown in the figure below.
Here, as the loop rotates, the current inside the wire AB is found by applying this rule. The current flows inside the wire AB for half cycle. As the loop rotates, the current inside the wire AB reverses for the other cycle. The same thing happens in the other wires too I,e in BC, CD, and DC. Therefore, the current direction changes for every half-cycle as the loop rotates. The working of the Alternating Current Generator considering two cases is shown in the fourth photo.
The loop end is connected to slip rings and is responsible for the movement of the wires as the loop rotates. The slip rings are connected to the brushes, the current passes from the slip ring to brushes and then to the load. These slip rings are used to slip smoothly because they are attached to the brushes in order that there is no twisting of the winding.
Answer:
Explanation:
The device which converts mechanical energy
into electrical energy in the form of alternating
current is called AC generator.