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

Inledning

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:

  • Industriella fabriker
  • Kommersiella byggnader
  • Transformatorstationer för allmännyttiga tjänster
  • Solkraftverk
  • Vindkraftsprojekt
  • Mining facilities
  • Datacenter
  • 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 till 500 MVA, inklusive:

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
  • Magnetisk kärna
  • Isoleringssystem
  • Kylsystem
  • 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

Till exempel:

Nedstegstransformator

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
Hög brandsäkerhet
No oil leakage risk
Låga underhållskrav
Lämplig för installation inomhus
Miljövänlig
Common Applications

Three phase dry type transformers are commonly installed in:

Kommersiella byggnader
Sjukhus
Flygplatser
Datacenter
Industriella anläggningar
Köpcentrum

Typical ratings:

Kapacitet Tillämpning
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.

Fördelar

  • High power capacity
  • Utmärkt kylningsprestanda
  • Lång livslängd
  • Suitable for outdoor applications

Tillämpningar

Vanliga användningsområden är bland annat:

  • Transformatorstationer för allmännyttiga tjänster
  • Solcellsparker
  • Vindkraftsparker
  • Industriella anläggningar
  • 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

Applikationer:

  • Bostadsområden
  • Commercial facilities
  • Industriella fabriker

4. Three Phase Power Transformer

A trefasig krafttransformator is used in high voltage transmission and substations.

Applikationer:

  • Kraftverk
  • Grid substations
  • Projekt för förnybar energi

Effektområde:

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

Industriella kraftsystem

Factories rely on three phase transformers to supply power for:

  • Motorer
  • Compressors
  • Pumps
  • CNC-maskiner
  • Produktionslinjer
  • Automation equipment

Industrial transformers usually require:

  • Hög verkningsgrad
  • Kontinuerlig drift
  • Strong overload capability

Kommersiella byggnader

Three phase transformers are commonly used in:

  • Kontorsbyggnader
  • Hotell
  • Köpcentrum
  • Flygplatser

A common North American system:

480V → 208Y/120V

This voltage system is widely used for:

  • Lighting
  • VVS-system
  • Building equipment

Projekt för förnybar energi

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

Exempel:

Solar inverter:

800V

↓

Transformer:

0.8kV / 35kV

↓

Grid connection

Three Phase Transformer Voltage Ratings

Different countries use different voltage standards.

Nordamerika

Common voltages:

Primär spänning Sekundär spänning
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?

För att välja rätt transformator måste man utvärdera flera tekniska parametrar.

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. Ingångs- och utgångsspänning

Exempel:

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:

Transformator av torr typ

Outdoor:

Oljeisolerad transformator

5. Transformer Standards

Internationella projekt kan kräva:

  • UL certification
  • CSA certification
  • DOE efficiency
  • IEC-standarder
  • IEEE-standarder

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

Varför välja EverNew Transformer?

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

Our manufacturing capabilities include:

Product Range

  • Distributionstransformator
  • Transformator av torr typ
  • Oljeisolerad transformator
  • Padmonterad transformator
  • Krafttransformator

Technical Capability

Kapacitet:

15 kVA – 500 MVA

Spänning:

6kV – 500kV

Certifieringar

  • UL
  • CSA
  • CE
  • GOST
  • ISO

We supply transformers for:

  • USA
  • Kanada
  • Sydamerika
  • Europa
  • Asien
  • 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
  • Lindning av koppar eller aluminium
  • Metod för kylning
  • Required standards
  • Order quantity

How do I choose a three phase transformer size?

You should consider:

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

Slutsats

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
  • Metod för kylning
  • Installationsmiljö
  • Internationella standarder

Som yrkesverksam 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 är en erfaren expert inom transformatorområdet, erkänd för sin omfattande kunskap och expertis. Med många års erfarenhet har han etablerat sig som en framträdande person i branschen och bidrar med värdefulla insikter och analyser som kolumnist för ledande publikationer. Hans djupgående förståelse för transformatorteknik, i kombination med hans passion för att dela information, gör honom till en pålitlig källa för både proffs och entusiaster.

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