6kV Oil-Immersed Main Transformer

6kV oil-immersed distribution transformers are developed for 6kV/0.4kV, 50Hz power transmission and transformation systems, widely deployed in rural power grids, outdoor box substations, industrial and mining enterprises, centralized photovoltaic power plants, outdoor municipal power supply stations and other outdoor power distribution scenarios.

The products fully comply with GB/T 6451 national standard for oil-immersed power transformers, IEC 60076 international standard for power transformers and GB 20052 energy efficiency grade specifications. Core strengths include low manufacturing cost, outstanding heat dissipation, strong overload performance and long service life.

HY TRANSFORMER is a high-tech enterprise integrating R&D, production and sales of full-series transformers up to 220kV. Our oil-immersed transformer product line covers S11, S13, S15 high-efficiency energy-saving series. We also supply matching YB European-style box-type substations and American prefabricated substations to provide one-stop complete power distribution solutions for clients.

1. High-Grade Raw Materials & Mature Winding & Tank Manufacturing Process

The iron core adopts high-permeability low-loss cold-rolled oriented silicon steel sheets; windings are wound with 99.9% oxygen-free pure copper conductors, which effectively reduce copper loss and temperature rise. The whole coil undergoes vacuum drying and oil immersion treatment, equipped with corrugated radiators for natural circulation heat dissipation. The fully sealed oil tank structure isolates internal windings from humid air, with stable partial discharge value. It can withstand long-term heavy load and harmonic interference from photovoltaic grid connection, meeting both conventional distribution and PV step-up transformer technical requirements.

2. Excellent Heat Dissipation & Stable Operation Under Harsh Outdoor

Conditions Insulating transformer oil acts as both cooling and insulating medium, with far superior heat transfer efficiency than air cooling. The whole machine can operate stably under high temperature, dust, light salt fog outdoor environments. Equipped with oil level gauge, temperature gauge, pressure relief valve and other safety accessories, it effectively prevents overheating and internal short-circuit failures.

3. Ultra-Low Energy Consumption & Strong Overload Capacity

Magnetic circuit and winding layout are optimized for 6kV power grid operating characteristics. No-load loss and load loss reach national Class 1 energy efficiency standard. The oil circulation cooling system supports long-term continuous heavy-load operation, and can withstand 150% short-time overload without overheating damage, with overall service life exceeding 30 years under normal maintenance. The operating noise is controlled below 55dB at 1 meter, meeting urban environmental noise limits.

4. Full Customization for Multiple Working Conditions

Standard modular design supports flexible customization of rated capacity, high-voltage tapping range, connection group, impedance voltage, outer protection shell and auxiliary accessories. We can produce tailor-made 6kV photovoltaic step-up oil-immersed transformers, mining flameproof oil transformers and special boost transformers to match rural power grids, large-scale photovoltaic bases, factory outdoor power stations and industrial park power supply systems.

5. Low Initial Procurement Cost & Flexible Outdoor Layout

Under the same rated capacity, oil-immersed transformers have lower purchase cost than dry-type transformers. They have no strict restrictions on indoor space, and are mainly used for outdoor installation. They can be arranged in remote unattended power supply points, reducing early-stage civil construction investment. Routine maintenance only requires regular oil quality testing and oil replenishment; failure rate remains low with standardized maintenance. Optional remote temperature signal transmission components support remote monitoring of outdoor substation equipment.

6. Large-Scale Production Capacity & Complete Lifecycle After-Sales

Service We own dedicated automatic production lines for oil-immersed transformers and have delivered thousands of outdoor power grid and photovoltaic engineering projects worldwide. Sufficient inventory and production capacity can stably deliver bulk orders of full-capacity 6kV conventional distribution transformers and PV dedicated oil transformers. We provide on-site installation commissioning guidance and lifelong professional technical after-sales support.

• 6kV oil-immersed distribution transformers are specially designed for 6kV/0.4kV 50Hz power supply and transmission systems, widely applied in:

• Rural overhead power grids, remote village outdoor power distribution stations

• Centralized ground photovoltaic power stations, mountain distributed PV projects (custom step-up transformers available)

• Outdoor power distribution stations of metallurgical, chemical, mining and manufacturing enterprises

• Municipal outdoor box substations, road lighting power supply systems

• Large industrial parks, chemical zones and unattended remote power supply points

Q1: Can 6kV oil-immersed transformers be applied to photovoltaic power stations? Do their loss indicators comply with IEC standards?

A: Yes. Our factory can develop customized full-copper photovoltaic step-up oil-immersed transformers based on standard 6kV oil transformer bodies. The no-load loss and load loss fully meet the energy efficiency requirements specified in IEC 60076. With strong anti-harmonic surge performance brought by oil insulation and large heat capacity, the products can be used as special PV grid-connected boost equipment, as well as general distribution transformers for industrial, mining and rural power grid projects.

Q2: What are the pros and cons of 6kV oil-immersed transformers compared with dry-type transformers of the same capacity?

A: Advantages of 6kV oil-immersed transformers:

1. Lower one-time purchase cost under equal capacity, more cost-effective for large-capacity equipment.

2. Superior oil circulation heat dissipation, stronger long-term continuous overload capacity, suitable for long-term heavy-load outdoor operation.

3. No high requirements for building fire protection, ventilation and indoor space, perfect for unattended remote outdoor power supply sites.

4. Larger heat storage capacity, better resistance to instantaneous impact load and harmonic fluctuation.

Disadvantages of 6kV oil-immersed transformers:

1. Filled with flammable insulating oil, not suitable for densely populated indoor areas such as shopping malls, hospitals and underground pipe galleries.

2. There exists risk of oil leakage; regular oil sampling, filtering or replacement maintenance is required, increasing long-term operation workload.

3. Oil waste disposal is needed after service life, which has certain environmental management requirements; cannot be directly installed in fully enclosed indoor public spaces.

Q3: What safety monitoring accessories are standard equipped on 6kV oil-immersed transformers?

A: Each standard 6kV oil-immersed transformer is equipped with complete safety monitoring parts: oil level indicator to observe real-time oil volume, winding temperature gauge to track operating temperature, pressure relief valve to release internal pressure in case of fault, and gas relay to detect internal short-circuit faults. We can additionally install temperature signal transmitters, remote alarm modules and oil quality online monitoring devices as customized options to realize remote data upload and fault early warning for unattended substations.

• GB/T 6451 Technical Parameters and Requirements for Oil-Immersed Distribution Transformers

• IEC 60076-1~9 Power Transformers International Standard

• GB 1094.1~11 General Standards for Power Transformers

• GB 20052 Minimum Allowable Values of Energy Efficiency and Energy Efficiency Grades for Three-Phase Distribution Transformers

• GB/T 7354 Partial Discharge Measurement for Electrical Equipment

Supplementary Technical Parameter Description

The product parameter table adopts the same capacity specification range as the reference document, with high voltage rated at 6kV, standard tapping range ±5% or ±2×2.5%, low voltage 0.4kV, connection group Dyn11 or Yyn0. Medium and small capacities adopt 4.0% short-circuit impedance, large capacities adopt 6.0% short-circuit impedance, with S13/S15 ultra-low loss design, strong heat dissipation and stable outdoor operation performance.