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

Voltage Ratio = Primary Turns / Secondary Turns

For example:

降压变压器

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:

商业建筑
医院
机场
数据中心
工业设施
Shopping centers

Typical ratings:

EverNew manufactures dry type transformers with:

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

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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.

优势

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

应用

常見的應用包括：

• 变电站
• 太阳能发电场
• 风电场
• 工業廠房
• Power transmission systems

Typical voltage ratings:

• 6kV
• 10 千伏
• 11 千伏
• 13.8kV
• 35 千伏
• 110 千伏
• 220 千伏

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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

应用：

• 住宅區
• Commercial facilities
• 工业厂房

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4. Three Phase Power Transformer

A 三相電力變壓器 is used in high voltage transmission and substations.

应用：

• Power plants
• Grid substations
• 可再生能源项目

功率范围

From several MVA to hundreds of MVA.

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Three Phase Transformer Applications

工业动力系统

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
• 連續運作
• Strong overload capability

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商业建筑

Three phase transformers are commonly used in:

• Office buildings
• Hotels
• 购物中心
• 机场

A common North American system:

480V → 208Y/120V

This voltage system is widely used for:

• Lighting
• HVAC systems
• Building equipment

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可再生能源项目

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

例如

Solar inverter:

800V

↓

Transformer:

0.8kV / 35kV

↓

Grid connection

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Three Phase Transformer Voltage Ratings

Different countries use different voltage standards.

北美

Common voltages:

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International Markets

Common systems:

EverNew transformers can be designed according to:

• IEC
• ANSI
• 电气和电子工程师学会
• UL
• CSA
• CE
• 社会变革管理计划

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How To Select A Three Phase Transformer?

Choosing the correct transformer requires evaluating several technical parameters.

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1. Transformer Capacity (kVA)

The transformer capacity must match the electrical load.

Common sizes:

• 15 千伏安
• 30 kVA
• 45 kVA
• 75 千伏安
• 112.5 千伏安
• 150 千伏安
• 500 千伏安
• 1000 千伏安
• 2500 千伏安

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2. Input and Output Voltage

例如

Commercial building:

Input:

480V Three Phase

Output:

208Y/120V Three Phase

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3. Frequency

Common frequencies:

• 50Hz
• 60Hz

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4. Transformer Cooling Method

Choose according to installation environment:

Indoor:

干式变压器

Outdoor:

油浸式变压器

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5. Transformer Standards

International projects may require:

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

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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

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為什麼要選擇 EverNew 變壓器？

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

我們的製造能力包括：

Product Range

• 配电变压器
• 干式变压器
• 油浸式变压器
• 垫装变压器
• 电源变压器

Technical Capability

容量

15 kVA – 500 MVA

电压

6kV – 500kV

认证

• UL
• CSA
• CE
• 社会变革管理计划
• ISO

We supply transformers for:

• 美国
• 加拿大
• 南美洲
• 欧洲
• 亚洲
• 非洲

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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.

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What is the most common three phase transformer voltage?

Common systems include:

• 480V
• 208Y/120V
• 400V
• 415V
• 13.8kV
• 35 千伏

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How much does a three phase transformer cost?

The price depends on:

• Transformer capacity
• Voltage rating
• Copper or aluminum winding
• 冷却方式
• Required standards
• Order quantity

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How do I choose a three phase transformer size?

You should consider:

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

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结论

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
• 冷却方式
• Installation environment
• 國際標準

作为专业人员 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.