The electrical machine is an electromechanical device which converts electrical energy into mechanical energy or, mechanical energy into electrical energy to perform a task. A transformer is also an electrical machine which acts as an electromechanical device to convert voltage from one level to another level.
Electrical Machines are the backbone of electrical engineering. They are devices that convert energy from one form to another—either electrical to mechanical, or mechanical to electrical. The classification of electrical machines is very important for students preparing for SSC JE, RRB JE, GATE, and other electrical engineering competitive exams. Below is the detailed hierarchy of electrical machines with proper sub-classifications.
1. Transformer
A transformer is a static device used to transfer electrical energy between two circuits through electromagnetic induction. Based on design and operation, transformers are classified as:
- Single Phase Transformer
- Three Phase Transformer
- Auto Transformer
2. Motor
A motor is an electrical machine that converts electrical energy into mechanical energy. Motors are broadly classified into AC Motors, DC Motors, and Special Motors.
2.1 AC Motor
AC Motors are widely used in industries and household appliances. They can be further classified into:
2.1.1 Induction Motor
- Single Phase Induction Motor
- Three Phase Induction Motor
2.1.2 Synchronous Motor
- Three Phase Synchronous Motor
- Reluctance Motor
- Hysteresis Motor
2.2 DC Motor
DC Motors are commonly used where speed control is required. They are classified as:
- DC Shunt Motor
- DC Series Motor
2.3 Special Motor
Special motors are designed for specific applications. They include:
- AC Series Motor
- Repulsion Motor
- Servo Motor
- Schrage Motor
- PCB DC Motor
- Stepper Motor
3. Generator
Generators are electrical machines that convert mechanical energy into electrical energy. They are divided into AC Generators and DC Generators.
3.1 AC Generator
AC Generators produce alternating current and can be further classified into:
3.1.1 Alternator
- Salient Pole Alternator
- Cylindrical Rotor Alternator
3.1.2 Induction Generator
3.2 DC Generator
DC Generators produce direct current and are classified into:
- DC Shunt Generator
- DC Series Generator
- DC Compound Generator
Classification of of Electrical Machines
For quick understanding, below is the hierarchical classification of Electrical Machines in tree format:
Electrical Machine │ ├── Transformer │ ├── Single Phase Transformer │ ├── Three Phase Transformer │ └── Auto Transformer │ ├── Motor │ ├── AC Motor │ │ ├── Induction Motor │ │ │ ├── Single Phase │ │ │ └── Three Phase │ │ └── Synchronous Motor │ │ ├── Three Phase Synchronous Motor │ │ ├── Reluctance Motor │ │ └── Hysteresis Motor │ ├── DC Motor │ │ ├── DC Shunt Motor │ │ └── DC Series Motor │ └── Special Motor │ ├── AC Series Motor │ ├── Repulsion Motor │ ├── Servo Motor │ ├── Schrage Motor │ ├── PCB DC Motor │ └── Stepper Motor │ └── Generator ├── AC Generator │ ├── Alternator │ │ ├── Salient Type │ │ └── Cylindrical Type │ └── Induction Generator └── DC Generator ├── DC Shunt Generator ├── DC Series Generator └── DC Compound Generator
Conclusion
In this article, we discussed the detailed classification of electrical machines, including Transformers, Motors, and Generators. This hierarchy is very useful for electrical engineering students and aspirants of SSC JE, RRB JE, GATE, and other competitive exams. Understanding the classification helps in building strong concepts in electrical machines, which is one of the most important subjects in the electrical engineering syllabus.
Frequently Asked Questions (FAQs)
Q1. What are the main classifications of Electrical Machines?
Electrical Machines are mainly classified into three categories: Transformers, Motors, and Generators. Each category is further divided into sub-types based on construction and working principle.
Q2. What are the types of Transformers?
The main types of transformers are: Single Phase Transformer, Three Phase Transformer, and Auto Transformer.
Q3. How are Motors classified?
Motors are classified into three main types: AC Motors, DC Motors, and Special Motors. AC Motors include Induction and Synchronous motors, DC Motors include Shunt and Series types, while Special Motors include Stepper, Servo, and Repulsion motors.
Q4. What are the different types of Generators?
Generators are classified as AC Generators and DC Generators. AC Generators include Alternators (Salient and Cylindrical) and Induction Generators, while DC Generators include Shunt, Series, and Compound generators.
Q5. Which Electrical Machine is used to convert electrical energy into mechanical energy?
Motors are used to convert electrical energy into mechanical energy.
Q6. Which Electrical Machine is used to convert mechanical energy into electrical energy?
Generators are used to convert mechanical energy into electrical energy.