Three phase dry type transformer 三相變壓器

規格 Detail Spec

Three phase auto type aluminum transformer with enclosure

Three phase isolation type aluminum transformer with enclosure

Three phase auto type copper transformer with enclosure

Three phase isolation type copper transformer with enclosure

The Role and Principles of Transformers

Transformers play a critical role in power transmission and distribution systems, handling both power conversion and electrical interconnection. Many everyday electrical appliances also contain built-in transformers or external adapters that convert incoming AC power to the required operating voltage.

1. Coil-Type Transformers

Coiltype transformers operate based on the principle of electromagnetic induction, using copper or aluminum windings. Two sets of windings are wrapped around a shared magnetic core — the winding connected to the power source is called the primary coil, and the other is the secondary coil.
When AC power flows through the primary coil, it creates a changing magnetic flux in the core, which then induces an alternating current of the same frequency in the secondary coil. This mechanism allows transformers to be used for either stepping up (boost) or stepping down (reduce) voltage levels.

2. Core Design and Materials

The design of the transformer core comes in various forms, but the primary requirement for core materials is high magnetic permeability. Core materials typically undergo heat treatment (annealing) and are composed of soft iron with added silicon steel, which allows them to generate more magnetic flux lines compared to other materials — significantly improving efficiency.

3. Transformer Losses

Ideally, a transformer would have 100% efficiency, where the power input on the primary side equals the power output on the secondary side. However, due to core magnetization and internal losses, real-world efficiency is inevitably lower. Transformer losses are generally divided into two types:

• No-Load Loss (Core Loss):
  This occurs even when the electrical equipment is not operating but the transformer is energized. These losses come from magnetizing the core and remain constant regardless of the load.

• Load Loss (Copper Loss):
  This arises when the electrical equipment is in use. It includes the power losses due to the load and the resistance in the windings. Using core materials with high magnetic permeability can effectively reduce load losses, helping to save energy and reduce electricity costs.

4. Transformer Noise (Hum)

Another common concern is transformer noise, often heard as a low-pitched "hum". This is caused by slight vibrations in the silicon steel laminations due to alternating magnetic flux. The vibration frequency matches the AC voltage frequency. If the power source contains harmonic distortion or the transformer design is poor, it may lead to abnormal or excessive noise.

Copper vs. Aluminum Conductors

Note: While aluminum conductors offer a cost advantage, they have lower conductivity.

Selection should be based on application requirements and budget considerations.

Autotransformer vs. Isolation Transformer

✅ Advantages & Disadvantages of Autotransformers

Advantages:

• Requires fewer conductor windings and silicon steel sheets, resulting in lower cost.

• High efficiency with minimal losses and better voltage regulation.

• Smaller size and lower temperature rise, saving space and energy.

Disadvantages:

• No isolation between primary and secondary sides; faults on the primary side may directly affect the secondary, leading to lower safety.

  
  

✅ Advantages & Disadvantages of Isolation Transformers

Advantages:

• Complete isolation between primary and secondary windings provides power filtering and protects downstream equipment.

• Effectively prevents fault currents from the primary side from reaching the secondary side, offering higher safety.

Disadvantages:

• Higher cost due to more conductor and material usage.

• Larger size and slightly lower efficiency; suitable for applications with higher demands on power quality.