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Common Types of Transformers in Power Systems: A Complete Guide

Release time:

2026-04-10 11:01

In modern power systems, transformers are the core equipment for achieving voltage conversion, power distribution, and system stability. Whether in industrial manufacturing, urban public utilities, or the booming renewable energy sector, selecting the right type of transformer is crucial for enhancing energy efficiency and ensuring system safety.

The following is a comprehensive analysis of the most common types of transformers in power systems and their core application scenarios.

Classification by Application

Type	Main Function	Key Features	Typical Applications
Power Transformer	Voltage step-up/down in transmission systems	High voltage (110kV+), large capacity, continuous full-load operation	Power plants, transmission networks, substations
Distribution Transformer	Step-down from medium to low voltage (400V/230V)	Close to end-users, fluctuating loads, 24/7 operation	Industrial parks, commercial buildings, residential areas
Instrument Transformer (CT/PT)	Measurement and protection	Converts high voltage/current into standard signals	Power monitoring, relay protection systems

Classification by Insulation & Cooling Method

Type	Cooling / Insulation	Advantages	Disadvantages	Typical Applications
Oil-Immersed Transformer	Transformer oil	Excellent heat dissipation, large capacity, cost-effective	Fire risk, requires maintenance	Outdoor substations, industrial grids
Dry-Type Transformer	Air / Resin	Safe, environmentally friendly, fire-resistant	Higher cost, smaller capacity	Data centers, hospitals, commercial buildings

Classification by Installation Environment

Type	Installation Location	Features	Suitable Environments
Indoor Transformer	Inside buildings	Low noise, fireproof, explosion-proof	Commercial complexes, hospitals, data centers
Outdoor Transformer	Open-air environments	Waterproof, corrosion-resistant, weather-resistant	Substations, industrial areas

Classification by Structural Form

Type	Structural Features	Advantages	Applications
Two-Winding Transformer	Primary + secondary winding	Simple structure, widely used	General power systems
Three-Winding Transformer	One input + two outputs	Flexible power distribution	Multi-voltage systems
Autotransformer	Shared winding	Compact size, high efficiency, lower cost	Ultra-high voltage transmission (220kV+)

Classification by Special Applications

Type	Function	Features	Applications
Compact Substation (Box-Type)	Integrated power distribution	Small footprint, fast installation	Urban distribution, renewable projects
Rectifier Transformer	AC to DC conversion	Used with rectifier systems	Electrolysis, electroplating, rail transit
Furnace Transformer	High-impact load supply	Strong overload resistance	Electric arc furnaces, metallurgy
Renewable Energy Transformer	Grid connection for renewables	Handles fluctuating power	Solar and wind power projects

Classification by Phase

Type	Features	Applications
Single-Phase Transformer	Simple structure, smaller capacity	Small-scale or special applications
Three-Phase Transformer	High efficiency, large capacity	Industrial and grid systems (mainstream)

Quick Selection Guide

Application Scenario	Recommended Transformer Type	Key Configuration	Selection Focus
Industrial Projects	Oil-immersed + distribution transformer	ONAN/ONAF cooling, copper winding	Reliability + cost
Data Centers	Dry-type (cast resin) transformer	Low loss, low noise, Class F/H insulation	Safety + stability
Outdoor Grid	Oil-immersed transformer	Anti-corrosion design, high IP rating	Environmental adaptability
Renewable Energy	Compact substation + step-up transformer	High efficiency, fluctuation resistance	Grid stability
Commercial Buildings	Dry-type transformer	Low noise, energy-saving	Safety + quiet operation
High-Voltage Transmission	Autotransformer	Large capacity, low loss	Investment optimization

Summary and Recommendations

When selecting a transformer, it is essential to balance the following three core dimensions:

Environmental Safety: Dry-type transformers are the preferred choice for indoor installations, while oil-immersed transformers are prioritized for outdoor environments.
Energy Efficiency Ratings: In response to national "Dual Carbon" policies, priority should be given to amorphous alloy or high-standard silicon steel products that meet Grade 1 or Grade 2 energy efficiency standards.
Load Characteristics: For data centers, the impact of harmonics generated by non-linear loads must be considered, necessitating the selection of specialty transformers with anti-harmonic capabilities.