table of the main classifications of transformers
The following is a table of the main classifications of transformers, categorized by core dimensions such as application and insulation method:
| Classification | Type | Key Characteristics & Principle | Primary Applications & Scope |
|---|---|---|---|
|
Purpose & Function |
Power Transformer | The core component for power transmission & distribution in electrical systems, with high capacity and voltage levels. | Used in power plants and substations for stepping up (e.g., 10.5kV/220kV) or stepping down (e.g., 110kV/10kV) voltage for efficient power transfer. |
| Distribution Transformer | The final step-down unit in the system, converting medium voltage (e.g., 10kV) to utilization voltage (e.g., 400V). | Supplies power to end-users like factories, residential complexes, and villages. | |
| Special Transformer | Designed for specific industrial or functional needs with unique construction or performance requirements. | Includes Rectifier Transformers (for electrolysis, traction), Furnace Transformers (for metallurgy), Mining/Shipboard Transformers (flameproof/durable). | |
|
Instrument Transformer (CT & PT) |
Steps down high voltage/current to standard values for measurement, metering, and protection, not for power transfer. | Installed in substations and switchgear to provide isolated signals to instruments and relays. | |
|
Voltage Regulating Transformer (On-load Tap Changer) |
Adjusts output voltage under load to maintain stable grid or process voltage. | Applied at grid nodes requiring high voltage stability or for sensitive industrial loads. | |
| Isolation Transformer | Provides galvanic isolation between primary and secondary windings (only magnetic coupling) for safety and noise reduction. | Used in medical equipment, data center servers, and precision instruments where interference immunity, shock protection, or ground loop elimination is critical. | |
|
Insulation & Cooling |
Oil-Immersed Transformer | Uses insulating oil as dielectric and coolant. Excellent cooling, high capacity, cost-effective. | The majority of outdoor substations and installations without strict fire hazards. |
| Dry-Type / Cast-Resin Transformer | Windings are encapsulated in epoxy resin or other solid materials. Fire-resistant, explosion-proof, maintenance-free. | Indoor locations with high safety demands: high-rise buildings, subways, data centers, hospitals. | |
| Gas-Insulated Transformer | Uses inert gases like SF6 as dielectric. Fire-resistant and compact. | For special indoor spaces with extreme fire safety requirements or space constraints (e.g., offshore platforms, urban underground substations). | |
|
Core Material |
Silicon Steel (CRGO) Transformer | Core made of grain-oriented silicon steel laminations. Mature technology, the most widely used. | The absolute mainstream for all conventional applications. |
| Amorphous Metal Transformer | Core made of amorphous alloy ribbons. No-load losses are 60-80% lower than silicon steel, offering significant energy savings. | Ideal for distribution scenarios with long-term light-load or no-load operation, such as rural grids or commercial areas with low nighttime load. | |
|
Phase |
Single-Phase Transformer | Used in single-phase AC systems, typically of smaller capacity. | Residential and commercial single-phase supplies, or combined to form three-phase banks. |
| Three-Phase Transformer | The standard for three-phase AC systems. | All industrial and large-scale power supply applications. | |
|
Winding Configuration |
Two-Winding Transformer | The most common type, with separate primary and secondary windings per phase. | The vast majority of voltage conversion applications. |
| Three-Winding Transformer | Has three windings per phase for linking three different voltage systems. | Used in hub substations that interconnect three voltage levels. | |
| Autotransformer | Primary and secondary windings share a common portion. More material-efficient and higher efficiency, but no electrical isolation. | Connecting power systems with similar voltage levels (e.g., 220kV/110kV), or used as motor starters. |
Importance Roles Of A transformer
A transformer is an electrical device that uses the principle of electromagnetic induction to change the voltage, current, and impedance of alternating current (AC). It has four main core functions, which together support the entire process from power generation and transmission to final consumption.
Core Function 1: Voltage Transformation
This is the most basic and primary function of a transformer.
Step-up: The voltage generated by power plants is relatively low. To transmit it over long distances and reduce energy loss along the lines, step-up transformers must significantly increase the voltage.
Step-down: After the electricity is transmitted to the consumption area, to meet the electricity needs of different users such as factories, businesses, and residents, step-down transformers and distribution transformers are used to gradually reduce the high voltage to a safe low voltage.
Core Function 2: Electrical Isolation
Transformers transfer energy through magnetic coupling, and their primary (input) and secondary (output) circuits are completely electrically isolated. This provides safety for personnel operation and equipment operation, effectively preventing electric shock accidents and eliminating interference caused by grounding potential differences between different devices. Isolation transformers, widely used in medical equipment, precision instruments, and data centers, are typical applications of this function.
Core Function 3: Impedance Matching
By changing the turns ratio of a transformer, the impedance can be proportionally changed squarely while transforming the voltage. This function is crucial in the electronics and communications fields. It ensures that the "internal resistance" of the signal source (such as a power amplifier) is optimally matched with the load (such as a loudspeaker), thereby enabling the signal to be transmitted with maximum efficiency and maintaining optimal sound or signal quality.
Core Function 4: Providing Specialized Power
Besides power systems, transformers are widely used in industrial and mining enterprises that require specialized power supplies.
For example:
Rectifier transformers: Provide DC power for the electrolysis and chemical industries.
Electric furnace transformers: Provide a large and stable current for smelting electric arc furnaces.
Instrument transformers: Used for measurement and protection, safely and proportionally reducing high voltage and high current for instrumentation.
Test transformers: Used to generate high voltage to test the insulation performance of electrical equipment.
In short, transformers are indispensable "energy adapters" and "safety isolators" in modern power systems and electronic equipment, playing a role throughout the entire chain of power production, transmission, distribution, and use.
standards for transformers
| Standard System | Standard |
|---|---|
|
China National Standards (GB/T) |
GB/T 1094 Series |
| GB/T 18494 Series | |
| GB/T 19212 Series | |
| GB 20052 | |
|
International Standards |
IEC 60076 Series |
| IEC 61558 Series | |
| IEEE C57.12.xx Series |
Products Description
LVZW-35 current transformer is a sensor used to measure large current in 35kV system.
It is mainly used in substations, power systems and electrical equipment.
The transformer adopts magnetic core type, which is characterized by high linearity, strong anti-interference ability, small size and simple structure.
LVZW-35 current transformer is a current transformer with very high cost performance.
Contact Us
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Contact: Melody Sun (Export Sales manager)
Email: xdtz03@westpowerelectric.com
Mobile: +86 180 9176 5658 (WhatsApp/Wechat)
