Temperature Monitoring for 500 kV Oil-Filled Submarine Cable Based on BOTDA Distributed Optical Fiber Sensing Technology: Method and Application | IEEE Journals & Magazine | IEEE Xplore

Temperature Monitoring for 500 kV Oil-Filled Submarine Cable Based on BOTDA Distributed Optical Fiber Sensing Technology: Method and Application


Abstract:

The 500 kV oil-filled ac submarine cables in the networking project of China’s southern coast are large capacity, ultrahigh-voltage cross-sea submarine power cables, whic...Show More

Abstract:

The 500 kV oil-filled ac submarine cables in the networking project of China’s southern coast are large capacity, ultrahigh-voltage cross-sea submarine power cables, which are 31 km long and bundled with submarine optical cables. Temperature monitoring on submarine cables is of great significance in controlling the ampacity and ensuring operational reliability. Referring to the submarine cables’ structural characteristics and setting conditions, a temperature monitoring system is established based on the Brillouin optical time-domain analysis (BOTDA) distributed optical fiber sensing technology. The thermal circuit model IEC60287 is modified and used to calculate internal temperature distribution. Moreover, an onshore simulation experimental platform is established on the same cables as the networking project with a special sealing and joint structures designed for filling oil and adding load, proving the accuracy of the temperature monitoring system and the calculation method. Finally, one example of the on-site operation and maintenances data is presented to show the actual working condition of the temperature monitoring system.
Article Sequence Number: 3504510
Date of Publication: 16 December 2021

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I. Introduction

The high-voltage submarine cables, as the main power transmission channel between islands and harbors, have been widely developed in the past century. Many countries worldwide have carried out various studies on them [1]–[3]. The rapid growth of demand for clean energy has promoted the construction of offshore wind farms and made the laying and stable operation of submarine cables more critical [4], [5]. The 500 kV submarine cables in the networking project of China’s southern coast have significant economic and social value [6]. They are all oil-filled cables, of which the onshore pumping station can control the internal oil channel status. At regular operation, the oil can be against the external seawater pressure and keep a high working electric field of the cables. When the submarine cables are damaged, the pumping station will drain oil outward to prevent sea water intrusion into the cables. Moreover, the submarine cable’s temperature while in operation is an important parameter to determine its loading and evaluate its operational status [7], [8]. As electricity demand continues to increase, the load also increases, leading to accretion in the operating temperature of the cables. The excessive load and temperature will accelerate the aging of the insulating material and even cause thermal breakdown, affecting the safe and stable operation of the power system. At the same time, the insulation faults of high-voltage cables are usually manifested by local temperature changes or abnormalities [9], [10]. Therefore, establishing a temperature online monitoring system of the submarine cable is significant to clarify its loading and ensure its safe operation.

References

References is not available for this document.