VGR Rings

Reliable Voltage Grading Components for Power Transformers

VGR Rings are precision‑engineered transformer components designed to control electric field distribution and reduce electrical stress at critical points. Manufactured from high‑purity cellulose materials with integrated conductive elements, they combine electrical performance, mechanical stability, and long‑term compatibility with liquid dielectrics in demanding transformer environments.

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Application Overview

Static Rings are primarily used in power transformers to manage voltage gradients and equalize electrical stress across insulation systems. Typical applications include:

High‑voltage winding terminations
Voltage grading in transformer insulation structures
Electric field control in critical high‑stress zones

By smoothing local field concentrations, static rings help protect insulation systems and improve the reliability of transformer designs.

What We Solve For

High electric field concentrations can accelerate insulation aging and increase the risk of partial discharge or failure. Static Rings (VGR Rings) address this challenge by:

Reducing voltage stress at critical insulation interfaces
Improving electric field uniformity around windings and leads
Enhancing long‑term dielectric performance in oil‑filled systems
Supporting stable mechanical performance over the transformer lifespan

This results in improved insulation protection, extended service life, and increased operational reliability.

TECHNICAL

Features & Functionality

Functionality & Options

Used for voltage grading and electric field control
Suitable for oil‑filled power transformers
Available as Shape A static rings, open or closed
Conductive pigtail for reliable electrical connection
Custom dimensions available on request
Designed for integration into transformer insulation systems

Key Technical Specifications

Insulation class: Class A (105 °C)
Core material: Precompressed pressboard
Pulp type: 100 % sulphate pulp
Core standard: IEC 641‑1 Type B 3.1
Conductive element: Metallized tinsel strip
Electrical connection: E‑Cu pigtail, 6 mm rope lay, semi‑flexible
Dielectric compatibility: Suitable for liquid dielectrics
Mechanical properties: High purity, low shrinkage, low compressibility

EXPERIENCE

Our Projects Featuring Insulect Industrial Materials

Explore our project highlights to see where Insulect industrial materials are making an impact.
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Fortescue Aldoga, New 275kV Substation Switchgear

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Fortescue Future Industries 275 kV Substation Project

ADVANTAGES

Why Choose Our VRG Rings

Designed to deliver dependable voltage grading and long‑term insulation performance, these VGR rings combine proven cellulose‑based materials with integrated conductive elements and robust mechanical design. They provide transformer manufacturers with a stable, standards‑compliant solution for controlling electric fields, protecting insulation systems, and ensuring reliable operation throughout the transformer lifecycle.

Optimized Electric Field Control

The integrated conductive elements and carefully engineered geometry help distribute voltage evenly, reducing localized electrical stress and protecting surrounding insulation.

Mechanical Stability for Long Service Life

Precompressed pressboard with uniform fibre orientation provides dimensional stability, high mechanical strength, and resistance to deformation during transformer operation.

Proven Compatibility and Standards Compliance

Manufactured in accordance with IEC 641‑1 and VDE 0530, these VGR Rings are fully compatible with oil‑filled transformer systems and support compliance in both new builds and refurbishment projects.

IMPLEMENTATION

Services & Support

Insulect offers comprehensive services and support for the products we manufacture and specialise in, enhancing value for local utilities, major energy users, equipment manufacturers, and service operators.

LOCAL TECHNICAL TEAM

Our local technical team provides exceptional support and expertise, ensuring quick response times and personalised service to tackle any challenges that may arise during project execution.

ENGINEERING DESIGN

Our team utilises advanced technology and industry knowledge to develop innovative and efficient solutions, customised to fit the unique requirements of each project.

PROCUREMENT & LOGISTICS

We facilitate smooth procurement and logistics processes by sourcing from trusted, proven partners and coordinating timely deliveries, ensuring projects remain on schedule and within budget.

TESTING & COMMISSIONING

Professional testing and commissioning support ensures that every system functions safely and reliably, adhering to all regulatory standards and client expectations.

TURNKEY PROJECT DELIVERY

We are able to oversee every phase from concept to completion, providing comprehensive solutions that simplify complex projects and ensure successful outcomes.

FACTORY VISITS

We facilitate client visits to our local manufacturing sites here in Australia, as well as overseas, for initial inspection as well as factory acceptance testing.