Process Selection And Adaptation Of Epoxy Resin Bushings In Substation Scenarios

In power systems, the epoxy bushing is a core component for connection and insulation, and its selection directly affects the reliability of substation equipment operation. From manufacturing processes to on-site installation, the technical standards at every stage are constantly evolving.

Regarding the process standards for prefabricated structures:

For high-voltage switchgear and transformers in substations, the industry currently prefers the epoxy resin bushing material formed using the APG (Automatic Pressure Gel) process. This process ensures uniform material flow within the mold, effectively eliminating internal air gaps, thereby achieving a higher partial discharge initiation voltage. Taking 40.5kV voltage level equipment as an example, the standard epoxy resin cast bushing must meet a 1-minute power frequency withstand voltage of 95kV, and the partial discharge quantity is typically controlled below 10pC. During installation, it is necessary to verify whether the flange interface complies with EN 50180 or EN 50181 standards to avoid mechanical stress concentration caused by dimensional tolerances.

Technical Details of Composite Insulation Structures

In substation applications in outdoor or highly polluted environments, single epoxy resin materials need to be composited with silicone rubber bushings.

• External Insulation Optimization: By composited high-temperature vulcanized silicone rubber with a epoxy bushing manufacturer outer layer, the hydrophobicity and migration properties of silicone rubber are utilized to improve the equipment's anti-flashover capability under salt spray or condensation conditions.

• Mechanical Load Verification: For wall bushings subjected to busbar tensile forces, their bending load capacity must be considered. Some designs increase the static bending strength to over 625N by pre-embedding stainless steel or glass fiber reinforcement materials in the epoxy layer to cope with conductor galloping under extreme weather conditions.

On-site Supervision and Quality Verification

For incoming epoxy bushing for transformer, strict incoming inspection is recommended. In addition to verifying the UL 94 V-0 flame retardant rating and RoHS environmental certification, attention should also be paid to whether the manufacturer has testing equipment such as DSC thermal analyzer and X-ray flaw detector. These methods can effectively identify incomplete curing of epoxy resin or the uniformity of distribution of internal reinforcing materials.