Transformer
A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to one or more circuits. A varying current in any one coil of the transformer produces a varying magnetic flux, which, in turn, induces a varying electromotive force across any other coils wound around the same core.

Transformer is a static electrical machine that is considered to be a backbone of a power system.
For generation, transmission and distribution of electric power, AC system is adopted instead of DC system because voltage level can be changed comfortably by using a transformer. For economic reasons, high voltages are required for transmission whereas, for safety reasons, low voltages are required for utilisation. Transformer is an essential part of power system. Hence, it is rightly said that transformer is a backbone of a power system.
In this page, we shall discuss the general features and principle of operation of single-phase transformers and three phase transformers.
Transformer Latest Posts
2 Important Distribution Transformer Testing Methods
Three-Phase Transformer – Basics and 2 Connection Methods
Open Delta (V-V) Connection of Transformers
Table of Contents
Transformer Basics
- Transformer Working Principle
- Why Transformers are Rated in kVA
- Transformer on DC Supply
- Voltage and Frequency Effects
- Power and Distribution Transformers
- Ideal Transformer and Practical Transformer
- Practical Transformer on No Load
- Comparison between Induction Motor and Transformer
Types of Transformer
- Power and Distribution Transformers
- Core Type and Shell Type Transformer
- Losses in a Transformer
- Voltage and Frequency Effects
- Rectifier Transformer
- Current Transformer – Working and Construction
- Why CT secondary should not be open?
- Types of Current Transformers
- CT Windings and Insulation Level
Three Phase Transformer
- Three Phase Transformer – Basics and Connection Methods
- Three Phase Transformer Interconnection
- Parallel Operation of 1 Phase Transformer
- Transformer Bushings
- Open Delta (V-V) Connection of Transformers
- Star-Star (Y-Y) Connection of Three Phase Transformers
- Why Three Phase System Preferred Over Higher Phases?
Transformer Oil
- Properties of Good Transformer Oil
- Transformer Oil Tests
- Transformer Oil Filtration
- Transformer Oil Testing – Video Training
Transformer Testing
- Type Test, Routine Test and Special Tests
- Condition Monitoring of Transformers
- Percentage Impedance of Transformer and Its Calculation
- How to Test Percentage Impedance of Transformer?
- Transformer All day Efficiency
- Electrical Bushings – Types, Purpose and Construction with Diagrams
- Difference between Dielectric Testing & Insulation Resistance Measurement
- Insulation Resistance Test (IR Test) or Megger Test