Applications and Advantages of 6-35kV Dry‑type Transformers

Dry‑type transformers rated from 6kV up to 35kV are essential components in modern medium‑voltage power distribution networks. Unlike oil‑immersed units, dry‑type transformers use no liquid insulation, making them inherently fire‑safe, environmentally friendly, and suitable for indoor installation near load centers. This voltage range covers a wide spectrum of applications, from rural distribution (6‑10kV) to industrial power supply (20‑22kV) and utility substations (33‑35kV).

Voltage Class Characteristics and Application Differences

6kV – 10kV Class

Advantages:

Lower insulation requirements, resulting in more compact and lighter construction.

Well‑suited for short‑distance power delivery, such as within a factory or campus.

Easier to manufacture and generally lower initial cost than higher voltage units.

Disadvantages:

Higher line losses over longer distances.

Limited to relatively low‑power transmission; not economical for large‑scale grids.

Typical Applications:

Industrial plants with on‑site generation.

Mining operations where distance between power source and load is short.

Legacy distribution networks in some Asian and European countries.

11kV – 15kV Class

Advantages:

A balanced choice between cost and performance.

Acceptable power delivery distance with moderate line losses.

Widely recognised in international standards (IEC, BS, ANSI).

Disadvantages:

Less efficient than 20‑22kV for large industrial parks or suburban grids.

Requires more substations for covering wide rural areas compared to 33kV.

Typical Applications:

Urban distribution in the United Kingdom, Ireland, and many Commonwealth countries (11kV is standard).

Commercial buildings, hospitals, and data centers.

Small‑scale renewable energy projects (e.g., solar farms up to a few MW).

20kV – 22kV Class

Advantages:

Significantly lower line losses than 10‑15kV for the same power throughput.

Allows fewer substations over a given area, reducing capital expenditure.

Used extensively in Europe (20kV) and parts of Latin America (22kV).

Dual‑voltage designs often allow operation at both 10kV and 20kV, easing grid upgrades.

Disadvantages:

Higher insulation cost and larger footprint than 10‑15kV units.

Not as widely standardised globally as 11kV or 33kV.

Typical Applications:

Distribution networks in Germany, Austria, Switzerland, and Scandinavian countries (20kV).

Industrial parks and large commercial developments.

Wind farms and solar plants in the 5‑20MW range.

30kV – 35kV Class

Advantages:

Very long power delivery distance with low line losses – ideal for rural electrification and feeding large industrial zones.

Reduces the number of primary substations needed.

33kV is a standard in many African, Middle Eastern, and Asian countries (ex‑British colonies).

35kV is widely adopted in China, Eastern Europe, and parts of South America.

Disadvantages:

Higher manufacturing complexity and cost.

Larger physical dimensions and weight, requiring more robust foundations and lifting equipment.

Not suitable for indoor installation in most commercial buildings.

Typical Applications:

Utility distribution networks serving large geographic areas.

Heavy industrial complexes (steel mills, cement plants, mining operations).

Connecting renewable energy plants to the transmission grid (e.g., 30‑50MW solar farms).

Railway traction power supply.

Voltage Level Selection Preferences by Country / Region

Different countries have adopted specific medium‑voltage standards based on historical, technical, and economic factors:

For export projects, KAIBEITE can manufacture dry‑type transformers for any of the above voltage classes, fully compliant with IEC, IEEE, or other local standards.

Key Advantages of KAIBEITE 6-35kV Dry‑type Transformers

KAIBEITE produces dry‑type transformers using high‑grade grain‑oriented silicon steel (CRGO) cores, which bring the following benefits:

Low no‑load losses – High permeability and low hysteresis loss of premium silicon steel significantly reduce core losses, meeting or exceeding Tier 2 energy efficiency requirements (GB 20052‑2024 and IEC 60076‑11).

Low noise operation – Advanced core joining techniques (step‑lap or butt‑lap) and optimized magnetic flux distribution lower audible noise to levels well below industry limits, making our transformers suitable for residential areas, hospitals, and libraries.

Long service life – Epoxy‑resin encapsulated windings provide excellent protection against moisture, dust, and chemicals. Properly maintained units can operate for over 30 years.

Excellent overload capability – Natural cooling (AN) permits 120% continuous load; forced air cooling (AF) can increase capacity to 150% for temporary peak demands.

Fire safety – Self‑extinguishing materials produce no toxic gases, ideal for indoor and underground installations.

Low maintenance – No oil to test, filter, or replace – only occasional cleaning of air ducts.

Proven Applications

KAIBEITE dry‑type transformers have been widely deployed in:

Shopping centres, high‑rise office buildings, and hotels – where fire safety and low noise are critical.

Residential communities and housing estates – indoor or underground substations.

Hospitals and healthcare facilities – reliable, maintenance‑free power for medical equipment.

Industrial plants – powering automation lines, compressors, pumps, and CNC machines.

Photovoltaic (PV) power plants – step‑up transformers from inverter voltage to medium voltage (e.g., 0.4/10kV, 0.69/20kV, 0.8/35kV).

Wind farms – turbine step‑up units and collector substation transformers.

About KAIBEITE

KAIBEITE is a transformer manufacturer with over 15+ years of experience, specialising in the design, research, and production of electrical equipment. Our main business includes oil‑immersed and dry‑type transformers, prefabricated substations, and high‑ and low‑voltage switchgear. We export to Asia, Europe, South America, and Africa, offering fully customised solutions for any medium‑voltage requirement. For a quotation or technical consultation, please contact us.

Production proces

Cooperation Partners

Our Exhibition

Payment & Delvery

ISO management system certification