Factory Joint Partial Discharge Testing for Longer High-Voltage Cables
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Solution Overview
Problem
Existing methods struggle to perform high-sensitivity partial discharge tests on longer lengths of joined high voltage cables and/or at higher voltage levels due to the challenges of energizing the entire length of the joined cables.
Innovation Solution
A system and method involving insulation and earthing systems, a high voltage transformer, and a partial discharge sensing system to test factory joints in high voltage cables, allowing for separate testing of cable sections and factory joints, with a focus on grounding and insulating the semiconductive sheaths to detect partial discharges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the entire length of joined high voltage cable is tested in one operation, then the testing efficiency is improved, but the measurement precision deteriorates due to inability to energize the entire length
Solution Approach 1:
The patent divides the joined cable into separate cable sections and tests each section individually by energizing them separately. This segmentation allows high-sensitivity partial discharge testing of each section while maintaining overall testing efficiency through systematic sequential testing of divided segments.
2Ease of operation
If factory joints are used to join cable sections, then the ease of operation is improved by maintaining spooling capability, but the device complexity increases due to additional insulation and earthing systems
Solution Approach 1:
The factory joint is segmented into distinct functional components: joint conductor for electrical connection, joint insulation system for electrical isolation, and joint semiconductive sheath with earthing system. This segmentation allows each component to perform its specific function while maintaining overall system manageability and spooling capability.
Solution Approach 2:
The joint insulation system and earthing system act as intermediary elements between cable sections. These intermediaries provide necessary electrical isolation and grounding while maintaining mechanical continuity, enabling both operational ease and controlled complexity.
3Measurement precision
If separate testing of cable sections and factory joints is performed, then the measurement precision is improved, but the loss of time increases due to multiple testing operations
Solution Approach 1:
Cable sections are prepared with insulation and earthing systems installed during manufacturing before installation. This preliminary action ensures that when separate testing is performed, the test setup time is minimized and high-sensitivity measurements can be conducted efficiently on pre-prepared sections.
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
Enables high-sensitivity partial discharge testing of factory joints, enabling the evaluation of longer lengths and higher voltage levels in joined cables, ensuring the electrical integrity of the cable assembly.
Implementation Method 1
a high voltage transformer for supplying a test voltage to the semiconducting sheath of the factory joint during a test period
Implementation Method 2
a partial discharge sensing system for sensing partial discharges in the factory joint during the test period
Data Source
Figure 1a~1c
Figure 2~3
Figure 4~5
AI summary
The present invention relates to a system (10) for performing a partial discharge test of a factory joint (1) joining a first high voltage cable section (2) and a second high voltage cable section (4). The system (10) comprises a first insulation system (40) for electrically insulating a joint side part (2SJ) of the first semiconductive sheath (2S) from a remaining part (2SR) of the first semiconductive sheath (2S) and a second insulation system (50) for electrically insulating a joint side part (4SJ) of the second semiconductive sheath (4S) from a remaining part (4SR) of the second semiconductive sheath (4S). The remaining part (2SR) of the first semiconductive sheath (2S), the remaining part (4SR) of the second semiconductive sheath (4S) and the first conductor (2C) and/or the second conductor (4C) of the respective cable sections are grounded. A high voltage transformer (20) is supplying a test voltage to the semiconducting sheath (1S) of the factory joint (1S) during a test period. A partial discharge sensing system (30) for sensing partial discharges in the factory joint (1) during the test period.