66kV Üç Fazlı Yağ İşlemeli Ayar Tranformatoru

Product Overview

As a pioneer and the first dedicated original equipment manufacturer (OEM) in China's neutral grounding transformer industry, we have laid the original benchmark for the industry's development with our profound technical strength accumulated through decades of intensive cultivation. From the independent R&D of core technologies to large-scale mass production, we have built a full-process independently controllable system. Relying on our stable and leading product performance and unparalleled reliability, we have become a preferred partner in the field of power grid construction.

Rockwill delivers reliable and high-performance earthing transformers designed for 66kV power systems. Our oil-immersed transformers are engineered to provide stable neutral grounding solutions while ensuring operational safety and system protection. Manufactured in compliance with international standards including IEC and GB, these transformers incorporate premium materials and rigorous quality control throughout production.

Basic Info.

Some of these earthing transformers cover voltage levels including：3.3kV / 6kV / 11kV / 15kV / 20kV / 22kV / 30kV / 33kV / 34.5kV / 36kV / 44kV / 66kV / 88kV / 110kV / 132kV / 145kV / 150kV / 220kV / 275kV / 330kV / 400kV, etc. The current withstand time ranges from 1s, 2s, 3s, 5s, 6s, 8s, 9s, 10s, 30s, 60s, 1hour to 2hours, and customization is available.

Key Features

• Voltage Class: 66kV system voltage (200 BIL)

• Capacity Range: Standard units from 100kVA to 10,000kVA

• Winding Configuration: Optimized zigzag (ZNyn) design

• Cooling System: ONAN/OFAF cooling options

• Insulation: Mineral oil or synthetic ester fluid

• Construction:

• Corrugated tank or radiator cooling

• Hermetically sealed or conservator tank options

• CRGO silicon steel core

• Copper/aluminum windings

Technical Advantages

• Enhanced Safety: Built-in Buchholz relay and pressure relief device

• Low Impedance: Zero-sequence impedance <15Ω for effective fault current management

• Durability: Corrosion-resistant paint system for outdoor installations

• Efficiency: Reduced no-load losses through optimized core design

• Flexibility: Off-circuit tap changer (±5% in 2.5% Steps)

Typical Applications

Utility Networks:

• Neutral grounding for 66kV transmission systems

• Arc suppression coil connections

• Resistance grounding systems

 Industrial Plants:

• Petrochemical facilities

• Mining operations

• Steel manufacturing plants

Renewable Energy:

• Wind farm collector stations

• Solar PV substations

• Hydroelectric plants

Performance Specifications

• Temperature Range: -30°C to +40°C Ambient

• Humidity: ≤95% Monthly Average

• Altitude: Up to 2000m ASL

• Sound Level: ≤75dB at 1m

• Efficiency: ≥99.2% at Full Load

Testing Protocol
All units undergo comprehensive testing including:

• Zero sequence impedance measurement

• Induced overvoltage test (260Hz)

• Lightning impulse test (350kV)

• Temperature rise test (65K max.)

• Oil dielectric strength test (≥50kV)

Service Conditions

• Suitable for indoor/outdoor installation

• Wind resistant up to 35m/s

• Non-explosive environments

• Seismic capability: 0.3g horizontal acceleration

Application Fields

• 66kV/88kV/110kV/132kV Power Distribution Network Construction

• New Energy Power Plants (e.g., Wind Power/Photovoltaic)

• Power Distribution Stations in Large Industrial Parks

• Railway Traction Power Supply Systems

• Urban Power Grid Upgrading and Renovation Projects

• High-Voltage Power Supply Systems for Industrial and Mining Enterprises

• Grounding Protection Projects of Regional Substations