Split Core Instrument Transformer for Conductor Measurement
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Solution Overview
Problem
Conventional current transformers for high voltage conductors require cutting and splicing, which is undesirable, and existing solutions do not adequately address the need for accurate measurement without compromising the integrity of the conductor.
Innovation Solution
A split core instrument transformer design with a cover section and base section, where the core segments are encapsulated in polymer resin except for the end surfaces, allowing for secure alignment and attachment without insulation, enabling accurate current measurement by maintaining the core segments at the same potential as the high voltage conductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional current transformer with unitary core is used, then measurement function is achieved, but conductor cutting and splicing is required which is undesirable
Solution Approach 1:
The current transformer core is divided into two separate segments that can be assembled around the conductor without cutting it. The first core segment and second core segment are positioned on opposite sides of the conductor, allowing the transformer to be installed by clamping onto an existing conductor rather than requiring conductor modification.
2Ease of operation
If split core design is used to avoid conductor cutting, then installation convenience is improved, but core segment alignment and contact precision deteriorates
Solution Approach 1:
Both core segments are encapsulated in polymer resin and brought to the same electrical potential as the high voltage conductor through conductive connectors. This equipotential design eliminates insulation requirements between the core segments and conductor, allowing for tighter tolerances and better alignment precision without electrical isolation constraints.
Solution Approach 2:
Conductive connectors serve as intermediaries between the high voltage conductor and the core segments. These connectors ensure precise electrical and mechanical contact while maintaining alignment between the split core segments, transferring the conductor's potential to both core segments uniformly.
3Reliability
If insulation is added to protect core segments from high voltage, then electrical safety is improved, but measurement accuracy deteriorates due to increased distance
Solution Approach 1:
The core segments are brought to the same electrical potential as the high voltage conductor through conductive connectors and polymer resin encapsulation. This equipotential design eliminates the need for additional insulation layers between the core segments and the conductor, maintaining minimal distance for accurate magnetic coupling while ensuring electrical safety.
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
This design enhances measurement accuracy by eliminating the need for insulation, allowing closer contact of core segments and improving load current measurement precision to meet metering class standards.
Implementation Method 1
encapsulated in polymer resin except for the end surfaces, allowing for secure alignment and attachment without insulation, enabling accurate current measurement by maintaining the core segments at the same potential as the high voltage conductor
Implementation Method 2
instrument transformer for measuring the properties of electricity flowing in an elongated conductor
Data Source
AI summary
An instrument transformer for measuring properties of electricity in a power line is provided. The instrument transformer includes a cover section releasably secured to a base section. The cover section includes a first core segment encapsulated in a first encasement formed from a polymer resin. The base section includes a second core segment with a low voltage winding mounted thereto and a voltage transformer, all of which are encapsulated in a second encasement formed from a polymer resin. When the cover section and the base section are secured together, the first core segment adjoins the second core segment, thereby forming a current transformer having a core formed from the first and second core segments. A method for making the instrument transformer includes the connection of the cover section to the base section to form a passage through which a high voltage conductor may extend.