Aluminum Corona Rings For High Voltage Bushings: The FAQ Guide

Are you looking forward to having a plan or coming up with an idea to purchase aluminum corona rings for high voltage bushings projects?

Aluminum corona rings are mainly used in high voltage bushings. They are easy to operate, convenient to move, and fast to install.

Here let Highv team introduce the design and production of aluminum corona rings for high voltage bushings.

Then you will be able to get a clear and a crisp understanding of how aluminum corona rings are used for high voltage bushings.

High voltage bushings test produces high voltage, which cause the non-uniform local electric field.

The function of the corona ring is to distribute the electric field gradient and lower its maximum values below the corona threshold, either preventing corona discharge entirely or transferring its destructive effects from the valuable hardware to the ring.

A very similar related component, aluminum corona shielding cover, is also used on the top head of high voltage bushings.


What Is The Transformer High Voltage Bushing

The transformer high voltage bushing is the main insulation device outside the transformer box.

The lead wires of the transformer windings must pass through the insulating sleeve to insulate between the lead wires and between the lead wires and the transformer casing, and at the same time play the role of fixing the lead wires.

Due to the different voltage levels, the insulating bushing has the form of pure porcelain bushing, oil impregnated bushing and capacitor bushing.

Pure porcelain bushings are mostly used in transformers of 10kV and below. It wears a conductive copper rod in the porcelain bushing, and the inside of the porcelain bushing is air insulated.

Oil impregnated bushings are mostly used in 35kV transformers. They are filled with oil in the porcelain bushing, and a conductive copper rod is inserted in the porcelain bushing, and the copper rod is covered with insulating paper.

Capacitor bushings are used on high voltage transformers above 100kV.
It is composed of main insulation capacitor core, outer insulation upper and lower ceramic parts, connecting bushing, oil pillow, spring assembly, base, corona shielding sphere, measuring terminal, connection terminal, rubber gasket, insulating oil, etc.

What Is The High Voltage Wall Bushing

The high voltage wall bushing refers to a device that allows one or several conductors to pass through a wall partition for insulation and support.
It is an important component in the power system.

In the process of manufacturing, transportation, and maintenance of high voltage wall bushings, latent defects may remain due to various reasons.

During long-term operation, defects will gradually occur due to the effects of electric field and conductor heating, mechanical damage, chemical corrosion, and atmospheric conditions.

What Is The HVDC Bushing

According to different applications, HVDC bushings can be divided into HVDC transformer bushings, HVDC converter transformer valve side bushings, HVDC fully enclosed combined electrical (GIS) outlet bushings and HVDC wall bushings and so on.

  • The HVDC transformer bushing is drawn from the transformer tank and connected to the power transmission line, which is the current carrying channel for the lead-in or lead-out wire of the transformer winding.
  • The valve-side bushing of the HVDC converter transformer passes through the converter valve hall and is connected to the converter valve. It is the lead-in or lead-out wire carrying channel of the valve side winding of the converter transformer.
  • The HVDC GIS outlet bushing is the current carrying channel of the GIS equipment lead wire, which is used to safely connect the transmission line.
  • The HVDC wall bushing is the necessary channel for the power transmission of the converter station. It connects the DC transmission line outside the converter valve hall and the converter valve in the converter valve hall to introduce or draw HVDC power.

In HVDC engineering applications, the bushing operating environment is complex and needs to withstand the comprehensive working conditions of ultra-high voltage, high current, mechanical tension, vibration and atmospheric pollution.

This puts forward higher requirements on the electrical performance, mechanical performance, temperature rise control, and sealing performance of the casing.

The structure scheme, insulation material and production process of conventional voltage grade bushings cannot be directly applied to UHV bushings.

Why Big Size Aluminum Corona Rings Are Used For Ultra High Voltage Bushings

High voltage can result in unwanted noise and corona, especially in the high voltage bushings testing which voltage is ultra high.

So aluminum corona rings are needed to suppress the UHV corona.

Aluminum corona rings and shielding covers are common parts in high voltage bushings. They are easy to operate, convenient to move, and fast to install.

In fact, the diameter of aluminum corona ring body have the main influence for corona effect.

For example, 750mm-1000mm outside diameter with 3mm thickness wall thickness aluminum corona ring is widely used for 220kV transformer bushings.

Here we should introduce our processing capabilities of the large outer diameter of aluminum corona rings.

The biggest outer diameter dimension of super aluminum corona ring is up to 16000mm. And pipe inner diameter of aluminum corona ring is 3000mm. Wall thickness of pipe will be from 2.0mm to 10mm.

During the production process, our team will check the sizes frequently and input our Just-in-Time record. This could ensure all corona rings are within the good tolerances.


Clearly, the aluminum corona rings are the major parts for high voltage bushings testing application.

HIGHV is the professional aluminum corona rings manafacturer and corona shielding solutions supplier.

For more than 28 years, we’ve offered our expertise to businesses of all sizes looking to quality aluminum corona rings in everything from high voltage bushings and insulators production to UHVDC research and development.

Our expert team members are available to help you determine the best aluminum corona rings for high voltage bushings solutions to help you meet your goals. Call us today.