Develop an online system for 66kV sheath fault detection/location: phase II

• Main Author: Lim, Zhi Feng
• Other Authors: Foo Yi Shyh Eddy
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/157699
• Institution: Nanyang Technological University

This project is an industry project between SP Group and Nanyang Technological University, which will focus on cable sheath fault detection for underground cables. Underground cables must be tested regularly to check for the cables’ integrity to maintain the stability and reliability of power transmission. The process to conduct cable sheath test to detect cable sheath fault requires lots of manpower, cost, and time. Cable sheath test requires a pre-check on the link boxes which will take up to a few days as there are many link boxes located along the line. Each link box is a cross bonding point between the cable. After the pre-check is done, the cable will be de-energised before cable sheath test can be conducted. To conduct the test, a 1kV DC voltage will be injected into the cable sheath to test the withstand voltage. This process can only be conducted on one cable at each point in time. One team will conduct the test, then look for anomalies at each link box junction. Anomalies are observed when operating the insulation resistance and leakage current test on cable sheath, and it is unable to hold and withstand 1kV for 1 minute. Thus, the objective of this project is to develop a new solution without de-energising the cable when conducting cable sheath checks online. As there is no existing product or idea to do an online system for 66kV sheath fault detection or location, research has been conducted, which includes research on induction device, converters, rectifiers, and battery sizing. The site visits provided clearer visualisation on how the test is done. Discussion with the co-supervisors and consultation with the professors from various fields were done to have better understanding on the technical specifications.