Dc and ac machines short notes pdf
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Definition : Electric motor is the electro-mechanical machine which converts the electrical energy into mechanical energy. In other words, the devices which produce rotational force is known as the motor. The working principle of the electric motor mainly depends on the interaction of magnetic and electric field.
Universal Motor - construction, working and characteristics
The conversion of this mechanism is known as the commutator, thus these machines are also named as commutating machines. DC machine is most frequently used for a motor. The main benefits of this machine include torque regulation as well as easy speed. The applications of the DC machine is limited to trains, mills, and mines. For example, underground subway cars, as well as trolleys, may utilize DC motors. In the past, automobiles were designed with DC dynamos for charging their batteries.
We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you! Published by Ariel McGee Modified over 2 years ago. Discuss the operating differences between different types of generators Understand the principle of DC generator as it represents a logical behavior of dc motors. Most DC machines are similar to AC machines: i.
A DC motor is any of a class of rotary electrical motors that converts direct current electrical energy into mechanical energy. The most common types rely on the forces produced by magnetic fields. Nearly all types of DC motors have some internal mechanism, either electromechanical or electronic, to periodically change the direction of current in part of the motor. DC motors were the first form of motor widely used, as they could be powered from existing direct-current lighting power distribution systems. A DC motor's speed can be controlled over a wide range, using either a variable supply voltage or by changing the strength of current in its field windings. Small DC motors are used in tools, toys, and appliances. The universal motor can operate on direct current but is a lightweight brushed motor used for portable power tools and appliances.
power factor compensators (synchronous condensers). ii) Asynchronous (Induction) Machines: • Induction Motors: Most widely used electrical motors in.
In electrical engineering , an armature is the component of an electric machine which carries alternating current. The armature can be on either the rotor rotating part or the stator stationary part , depending on the type of electric machine. The armature windings interact with the magnetic field magnetic flux in the air-gap; the magnetic field is generated either by permanent magnets, or electromagnets formed by a conducting coil. The armature must carry current , so it is always a conductor or a conductive coil, oriented normal to both the field and to the direction of motion, torque rotating machine , or force linear machine.
In actual practice, both of the primary and secondary windings have got some ohmic resistance causing voltage drops and copper losses in the windings. In actual practice, the total flux created does not link both of the primary and secondary windings but is divided into three components namely the main or mutual flux f linking both of the primary and secondary windings, primary leakage flux fL 1 linking with primary winding only and secondary leakage flux fL 2 linking with secondary winding only. The primary leakage flux fL 1 is produced by primary ampere-turns and is Proportional to primary current, number of primary turns being fixed. The self induced emf divided by the primary current gives the reactance of primary and is denoted by X 1. When a practical transformer is loaded Induced emf in secondary winding.
The magnetic flux in a d. The production of magnetic flux in the device by circulating current in the field winding is called excitation.