Applications of electrical machines

Application of electrical machines:

Electrical machines are electromechanical device which is used to convert electrical power in to mechanical power or mechanical power in to electrical power.

Electrical machines means it is consider as a motor and also consider as a generator. Both are electromechanical devices. Motor is used to convert electrical power into mechanical power. Generator is used to convert mechanical power in to electrical power.

Mainly two types of machines are available according to the source;

1) DC machines

2) AC machines

1) DC machines: This machines are uses DC power source like battery or rectifiers.  According to the construction of windings, three types of DC machines are available; series, shunt and compound DC machines.

DC motor is used where starting torque is required high. This motor can used in mixers, grinders. Previously this motors are used in crane and lift, but now days this motors are not used in this application.

Other applications like; Electric traction, Cranes, Elevators, Air compressor, Vacuum cleaner, Hair drier, Sewing machine.

Dc generators are used to generate DC power. In remote area, where electricity is not available at that area this is very useful.

2) AC machines: This is most used machines. Which includes Induction motor, synchronous motor.

       A) Induction motor: this motor is widely used in industries. Out of all this motors, more than 90% of motors are IM because this motor has low cost, high efficiency and easy in construction. This motors are used in application like; water pumps, kitchen appliances, fans and air conditioners, automobiles and common industrial machinery like boiler pumps and compressors.

        B) Synchronous motor: In this motor, speed of rotor is same as speed of rotor. So, rotor is rotating at a speed of synchronous speed. Synchronous motor runs at a constant speed at a given frequency irrespective of the load. But, the speed of an asynchronous motor reduces with the increase in the load.

This motor is required two power source; AC source is main source and DC source is also required for excitation. This motor is not self started. This motor is used in power stations to generate electricity at a desired frequency and also used to control voltage by changing its excitation in the transmission lines.