Current Transformer Core Layout for Compact GIS Cable Interfaces
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Solution Overview
Problem
The installation of conventional closed core current transformers in gas insulated switchgear is time-consuming and requires significant space, necessitating either pre-installation before high-voltage cable installation or using more expensive open cores that allow post-installation but at a higher cost and larger space requirements.
Innovation Solution
A current transformer arrangement featuring an adapter with a housing and annular current transformer core surrounding the exterior, which can be pre-installed and tested, allowing for easier measurement of current conductors through a connector with conical portions for a fluid-tight seal within the gas insulated switchgear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional closed core current transformers are installed around high voltage cables before cable installation, then measurement precision is ensured, but installation time increases and productivity decreases
Solution Approach 1:
The current transformer is divided into two separate parts: the annular core remains fixed within the gas insulated switchgear, while the measurement winding is integrated into a removable adapter that connects to the cable connector. This segmentation allows the core to be pre-installed and tested independently, while the winding can be installed or replaced without disturbing the core, thereby improving installation efficiency while maintaining measurement precision.
Solution Approach 2:
The annular current transformer core is pre-installed within the adapter housing and can be tested before the actual cable connection is made. This preliminary installation and testing of the core separates the measurement component setup from the cable installation process, allowing parallel execution of tasks and reducing overall installation time while ensuring measurement precision is verified in advance.
2Measurement precision
If conventional closed core current transformers are used, then measurement precision is maintained, but installation space requirements increase
Solution Approach 1:
The adapter with the measurement winding is designed to nest around the pre-installed annular core within the gas insulated switchgear. The adapter housing contains the winding and connects to the cable connector, while the core remains nested inside the switchgear structure. This nested configuration integrates the measurement components into the existing space without requiring additional external installation area, maintaining measurement precision while reducing space requirements.
3Adaptability or versatility
If open current transformer cores are used to allow post-installation, then installation flexibility improves, but cost and space requirements increase
Solution Approach 1:
By segmenting the current transformer into a fixed core and a removable adapter with winding, the invention achieves installation flexibility similar to open cores - the adapter can be installed or replaced after cable installation. However, the closed annular core structure maintains manufacturing simplicity and cost-effectiveness, avoiding the need for expensive open core designs while preserving the flexibility benefit.
4Measurement precision
If conventional current transformers are installed before cable installation, then measurement precision is ensured, but installation time and complexity increase
Solution Approach 1:
The segmentation of the current transformer into fixed core and removable adapter simplifies the installation process. The core can be pre-installed and tested within the switchgear, while the adapter with winding connects to the cable connector as a separate operation. This reduces installation complexity by allowing independent installation and testing of components, while the integrated design ensures measurement precision is maintained.
Solution Approach 2:
The core is preliminarily installed and tested within the adapter housing before final cable connection. This preliminary action separates the measurement system setup from cable installation, reducing overall installation complexity by allowing parallel task execution and independent verification of the measurement component functionality.
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 solution enables efficient and space-saving current measurement within gas insulated switchgear by allowing pre-installation and testing of current transformer cores, reducing installation time and costs while maintaining a compact design.
Implementation Method 1
an annular current transformer core surrounding an exterior of the housing for measuring a current of the current conductor
Data Source
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AI summary
A current transformer arrangement (300) for a gas-insulated switchgear is provided. The current transformer arrangement (300) includes an adapter (302) having a housing (308), the housing (308) defining a first end connection opening, a second end connection opening and a hollow interior, a current conductor (224) passing through the hollow interior of the adapter (300), and an annular current transformer core (304) surrounding an exterior of the housing (308) for measuring a current of the current conductor (224).