Three Phase Transformer: Working Principle, Types, Applications and Selection Guide

Three Phase Power Transformer Guide with Types, Applications and Complete Transformer Solutions for Industrial and Utility Systems

Introduction

A three phase transformer is one of the most widely used electrical transformers in industrial power distribution systems. It is designed to transfer electrical energy between three-phase power circuits while changing voltage levels efficiently and safely.

Three phase transformers are commonly used in:

  • Industriële fabrieken
  • Commerciële gebouwen
  • Onderstations van nutsbedrijven
  • Solar power plants
  • Wind energy projects
  • Mining facilities
  • Datacenters
  • Manufacturing plants

Compared with single phase transformers, a three phase transformer provides higher power capacity, improved efficiency, and better load balance, making it the preferred solution for medium voltage and high-power electrical systems.

As an experienced three phase transformer manufacturer, EverNew Transformer provides customized transformer solutions from 15 kVA tot 500 MVAmet inbegrip van:

What Is a Three Phase Transformer?

A three phase transformer is an electrical transformer designed for three-phase alternating current (AC) systems.

Unlike a single phase transformer, which operates with one alternating voltage waveform, a three-phase transformer uses three separate phases with a 120-degree phase difference.

The three phases provide:

  • Higher power transmission efficiency
  • Reduced conductor size
  • Better motor performance
  • More stable industrial power supply

A typical three phase transformer contains:

  • Three primary windings
  • Three secondary windings
  • Magnetic core
  • Insulation system
  • Koelsysteem
  • Transformer enclosure

Three Phase Oil Immersed Transformer for Industrial Power Distribution Systems and Utility Substation Applications

How Does a Three Phase Transformer Work?

The operating principle of a three phase transformer is based on electromagnetic induction.

When AC voltage is applied to the primary winding, it creates alternating magnetic flux inside the transformer core. This magnetic flux induces voltage in the secondary winding.

The voltage conversion ratio depends on the relationship between winding turns:

Voltage Ratio = Primary Turns / Secondary Turns

For example:

Step-down transformator

Input:

13.8kV

Output:

480V

The transformer reduces medium voltage electricity to a usable low voltage level for industrial equipment.

Three Phase Transformer Types

Three phase transformers can be classified according to construction, insulation method, cooling system, and application.

1. Three Phase Dry Type Transformer

A three phase dry type transformer uses air as the cooling and insulation medium instead of transformer oil.

Dry type transformers are widely used where fire safety and environmental protection are important.

Advantages of Dry Type Transformer
High fire safety
No oil leakage risk
Low maintenance requirements
Suitable for indoor installation
Environmentally friendly
Common Applications

Three phase dry type transformers are commonly installed in:

Commerciële gebouwen
Ziekenhuizen
Luchthavens
Datacenters
Industrial facilities
Shopping centers

Typical ratings:

Capaciteit Toepassing
15 kVA Small commercial loads
45 kVA Industrial equipment
75 kVA Building power supply
500 kVA Factory distribution
2500 kVA Large industrial systems

EverNew manufactures dry type transformers with:

  • Copper winding
  • Aluminum winding
  • Cast resin insulation
  • UL/CSA compliant designs

Three Phase Dry Type Transformer Coil Manufacturing and Copper Winding Process for Industrial Power Transformer Production

2. Three Phase Oil Immersed Transformer

A three phase oil immersed transformer uses insulating oil for cooling and electrical insulation.

Oil immersed transformers are commonly used for outdoor power distribution because they provide excellent heat dissipation and high capacity capability.

Voordelen

  • High power capacity
  • Excellent cooling performance
  • Long service life
  • Suitable for outdoor applications

Toepassingen

Common applications include:

  • Onderstations van nutsbedrijven
  • Zonneparken
  • Windparken
  • Industrial plants
  • Power transmission systems

Typical voltage ratings:

  • 6kV
  • 10kV
  • 11kV
  • 13.8kV
  • 35kV
  • 110kV
  • 220kV

3. Three Phase Distribution Transformer

A three phase distribution transformer is designed to reduce medium voltage electricity to low voltage for end users.

Typical conversion:

11kV → 400V

13.8kV → 480V

35kV → 400V

Toepassingen:

  • Residential areas
  • Commercial facilities
  • Industriële fabrieken

4. Three Phase Power Transformer

A three phase power transformer is used in high voltage transmission and substations.

Toepassingen:

  • Power plants
  • Grid substations
  • Renewable energy projects

Vermogensbereik:

From several MVA to hundreds of MVA.

High Quality Three Phase Transformer Winding Production Process with Copper Windings for Industrial Power Transformer Manufacturing

Three Phase Transformer Applications

Industriële energiesystemen

Factories rely on three phase transformers to supply power for:

  • Motors
  • Compressors
  • Pumps
  • CNC machines
  • Production lines
  • Automation equipment

Industrial transformers usually require:

  • High efficiency
  • Continuous operation
  • Strong overload capability

Commerciële gebouwen

Three phase transformers are commonly used in:

  • Office buildings
  • Hotels
  • Winkelcentra
  • Luchthavens

A common North American system:

480V → 208Y/120V

This voltage system is widely used for:

  • Lighting
  • HVAC systems
  • Building equipment

Projecten voor hernieuwbare energie

Solar and wind projects require transformers to increase voltage before grid connection.

Voorbeeld:

Solar inverter:

800V

↓

Transformer:

0.8kV / 35kV

↓

Grid connection

Three Phase Transformer Voltage Ratings

Different countries use different voltage standards.

Noord-Amerika

Common voltages:

Primaire spanning Secundaire spanning
480V 208Y/120V
600V 347/600V
13.8kV 480V
34,5kV 480V

International Markets

Common systems:

Primary Secondary
10kV 400V
11kV 415V
20kV 400V
35kV 400V

EverNew transformers can be designed according to:

  • IEC
  • ANSI
  • IEEE
  • UL
  • CSA
  • CE
  • GOST

Three Phase Transformer Manufacturing Process in Modern Transformer Factory with Advanced Production Technology

How To Select A Three Phase Transformer?

Choosing the correct transformer requires evaluating several technical parameters.

1. Transformer Capacity (kVA)

The transformer capacity must match the electrical load.

Common sizes:

  • 15 kVA
  • 30 kVA
  • 45 kVA
  • 75 kVA
  • 112,5 kVA
  • 150 kVA
  • 500 kVA
  • 1000 kVA
  • 2500 kVA

2. Input and Output Voltage

Voorbeeld:

Commercial building:

Input:

480V Three Phase

Output:

208Y/120V Three Phase

3. Frequency

Common frequencies:

  • 50Hz
  • 60Hz

4. Transformer Cooling Method

Choose according to installation environment:

Indoor:

Droge Type Transformator

Outdoor:

In olie ondergedompelde transformator

5. Transformer Standards

International projects may require:

  • UL certification
  • CSA certification
  • DOE efficiency
  • IEC standards
  • IEEE standards

Outdoor Three Phase Pad Mounted Distribution Transformer for Utility Substation and Renewable Energy Power Projects

Three Phase Transformer Manufacturer

Selecting a reliable three phase transformer manufacturer is important for ensuring safety, efficiency, and long service life.

A professional transformer supplier should provide:

✔ Engineering design support

✔ Factory testing

✔ International certifications

✔ Customized voltage solutions

✔ Export experience

Why Choose EverNew Transformer?

EverNew Transformer is a professional transformer manufacturer in China with more than 30 years of experience.

Our manufacturing capabilities include:

Product Range

  • Distributietransformator
  • Droge Type Transformator
  • In olie ondergedompelde transformator
  • Opgezette transformator
  • Voedingstransformator

Technical Capability

Capaciteit:

15 kVA – 500 MVA

Spanning:

6kV – 500kV

Certificeringen

  • UL
  • CSA
  • CE
  • GOST
  • ISO

We supply transformers for:

  • VS
  • Canada
  • Zuid-Amerika
  • Europa
  • Azië
  • Afrika

Three Phase Transformer FAQ

What is the difference between single phase and three phase transformer?

A single phase transformer is normally used for smaller loads, while a three phase transformer is designed for industrial and commercial power systems requiring higher capacity.

What is the most common three phase transformer voltage?

Common systems include:

  • 480V
  • 208Y/120V
  • 400V
  • 415V
  • 13.8kV
  • 35kV

How much does a three phase transformer cost?

The price depends on:

  • Transformer capacity
  • Voltage rating
  • Copper or aluminum winding
  • Koelmethode
  • Required standards
  • Order quantity

How do I choose a three phase transformer size?

You should consider:

  • Total connected load
  • Starting current
  • Future expansion
  • Voltage requirements
  • Efficiency requirements

Conclusie

A three phase transformer is an essential component in modern electrical power systems, providing efficient voltage conversion for industrial, commercial, and renewable energy applications.

Choosing the correct transformer requires careful evaluation of:

  • Power capacity
  • Voltage levels
  • Koelmethode
  • Installation environment
  • International standards

Als professional three phase transformer manufacturer, EverNew Transformer provides reliable transformer solutions worldwide with customized designs from low voltage distribution systems to high voltage power networks.

Contact EverNew Transformer today for your three phase transformer project.

    Jeremy

    Jeremy is een doorgewinterde expert op het gebied van transformatoren, erkend om zijn uitgebreide kennis en expertise. Met zijn jarenlange ervaring heeft hij zich gevestigd als een prominente figuur in de industrie en draagt hij waardevolle inzichten en analyses bij als columnist voor toonaangevende publicaties. Zijn diepgaande kennis van transformatortechnologie, gekoppeld aan zijn passie voor het delen van informatie, maakt hem tot een betrouwbare bron voor zowel professionals als liefhebbers.

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