Insulated Transformer Structure for Partial Discharge Suppression
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Solution Overview
Problem
Existing transformers face challenges in providing adequate insulation between the primary and secondary sides, particularly for high voltage applications, leading to issues such as partial discharge breakdown and manufacturing difficulties, especially in dry-type transformers.
Innovation Solution
The transformer design incorporates an insulating sheet with conductive or semiconductive coatings on both sides, split magnetic core sections, and optional protective coatings to equalize potential, reducing dielectric stress and preventing corona and partial discharge, and may include additional ridges or fins to increase clearance and creepage distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil is used as insulating medium, then thermal and dielectric properties are improved, but flammability and leak risk increase
Solution Approach 1:
The patent introduces an insulating sheet as an intermediary component between primary and secondary windings. This sheet provides the necessary insulation and dielectric properties without using oil, thereby eliminating flammability and leak risks while maintaining insulation reliability.
Solution Approach 2:
The patent extracts the harmful oil medium from the transformer structure and replaces it with solid insulating materials (insulating sheet with conductive coatings). This removal eliminates the harmful effects of oil while preserving the essential insulation function.
2Object-affected harmful factors
If dry-type transformer structure is used, then flammability and leak issues are eliminated, but partial discharge breakdown risk increases due to voids or air pockets
Solution Approach 1:
The patent applies conductive or semiconductive coatings on the surfaces of the insulating sheet that are in contact with the windings. These coatings equalize the electric potential distribution, eliminating sharp potential gradients that would cause corona discharge and partial discharge in voids or air pockets.
Solution Approach 2:
The patent changes the electrical parameters (conductivity) of the insulating sheet surfaces by applying conductive or semiconductive coatings. This parameter change transforms the insulating surface into an equipotential surface, preventing partial discharge while maintaining the dry-type structure's safety advantages.
3Weight of moving object
If high frequency operation is used, then transformer size and weight are reduced, but insulation challenges between primary and secondary sides increase
Solution Approach 1:
The patent uses a composite structure consisting of an insulating sheet with conductive or semiconductive coatings on its surfaces. This composite material provides both the necessary insulation for high voltage isolation and the equipotential surfaces needed to prevent partial discharge, enabling reliable high-frequency operation in a compact transformer.
Solution Approach 2:
The patent segments the insulation system into multiple functional layers: the base insulating sheet provides dielectric strength and voltage isolation, while the conductive or semiconductive coatings on its surfaces provide equipotential conditioning. This segmentation allows each layer to optimize its specific function, achieving both compact size and adequate insulation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the occurrence of corona and partial discharge, enhances insulation reliability, and improves manufacturing ease and cost-effectiveness by equalizing potential gradients and increasing clearance, thus enhancing transformer performance.
Implementation Method 1
The insulating sheet has a conductive or semiconductive coating on its surface facing the secondary side of the transformer and the said coating is electrically connected or referenced to the secondary winding and split core section proximal to the secondary winding such that they are all at substantially equal potential
Implementation Method 2
a magnetic core to couple the windings
Data Source
AI summary
A transformer with improved insulation is provided with an electrically insulating sheet separating the primary winding and a first split-core section from the secondary winding and a second split-core section. The insulating sheet is provided with coatings and the coatings are referenced to the primary side and the secondary side windings and cores to form equipotential surfaces and distribute the dielectric stresses across the transformer. Ridges are optionally added to the insulation sheet to increase creepage and clearance distances. The features described reduce the occurrence of corona and partial discharge in the transformer structure and surrounding space.