Operating Principle of Electrical Machines, its types and application

As an electrical engineer, you might know that the electrical machines are device that can perform a specified task with or without rest, just like a politician on the campaign trail.

Photo by Luca J on Unsplash

Here are some examples of electrical machines that can be seen in homes Ceiling fan, refrigerator, washing machine, Dish washer, Air Conditioner.

Operating principle of electrical machine

The basic working principle of an any electrical machine is based on electromagnetic induction law, which was formulated by Michael faraday in 1831.

Whenever the conductor moves in Magnetic field the EMF (Electro magnetic force) is induced in the conductor

EMF is nothing but Voltage or potential difference. 

Discovery of electromagnetic induction law

Michal Faraday discovered that the action of placing a current carrying conductor between magnetic field will cause the electrical conductor to experience the mechanical force. This phenomenon is called the electromagnetic induction law.

The mechanical force can be utilized for various applications such as in electric motors and generators.

Electrical machine Classifications

Generally, electrical machines can be classified in a number of ways including

• By type of energy converted

1. Electrical Motor : Convert electrical Energy into mechanical Energy
2. Electrical Generators: Convert Mechanical Energy into Electrical Energy

• By Type of Motion

1. Rotating Electrical Machine: Have a Rotating rotor and a stationary stator
2. Linear Electrical Machine: Have a Moving element that moves in a linear direction.

• By type of Magnetic Field

1. DC Electrical Machines: Use a Direct Current to create a magnetic field
2. AC Electrical Machines: Uses an alternating current to create a magnetic field

• By type of Construction

1. Static electrical Machine : Having no moving parts
2. Rotating electrical Machines : Having moving rotor and stationary stator

The classification names themselves explain the operation of electrical machines. Non-rotating machines are stationary machines that do not have moving parts and rotating machines have moving parts.

Machines that rotate are called dynamic machines, and machines that do not rotate are called static machines.

Application

Electrical Machines are used in a wide variety of applications including,

• Power Generation: Electrical generators are used to generate Electricity.
• Industrial Automation: Electrical motors are used to power a wide variety of machinery and equipment such as robots, Conveyors etc.
• Transportation: Electric Motors are used to power electric vehicles, trains and other transportation systems.