The integrated monitoring system for power cable tunnels is an effective technical means to enhance the maintenance capability of tunnel cables. By automatically monitoring and intelligently managing the equipment within the tunnel, users can remotely and in real-time understand various conditions such as the on-site video information, cable surface temperature, load current, leakage current, smoke detection inside the tunnel, environmental temperature and humidity, and manhole cover switches. This makes tunnel management more convenient and efficient.
The comprehensive monitoring system for power cable tunnels integrates various sensors and subsystems to meet the demands of modern power tunnel monitoring，allowing management personnel to easily access various information within the tunnel.
As a monitoring sensor at the data acquisition level, the fluxgate current sensor is primarily used in the power cable tunnel monitoring system to test cable load current, enabling the system to monitor the protective layer current of power tunnel cables in real-time. Compared with traditional industrial transmitter collection schemes, fluxgate current sensors offer the following advantages:
- Through-hole Input: When testing a conventional AC signal of 400A, the integrated installation is feasible. This is more cost-effective in practical applications compared to the traditional current transformer combined with a transmitter test scheme.
- Open-loop Design: The sensor's open-loop design facilitates on-site installation, testing, and maintenance. On-site installation does not require power interruption or cable disassembly, significantly reducing labor costs.
- Epoxy Sealing: The sensor is meticulously treated for waterproofing through epoxy sealing, and power supply and signal output are conducted through a 1-meter four-core shielded cable. This meets the harsh environmental conditions of tunnel monitoring, especially high humidity, achieving an IP67 protection rating. It ensures high safety and reliability, preventing potential power grid accidents caused by sensor faults or errors.
Fluxgate current sensors are suitable for isolating and converting complex signals such as AC, DC, and pulses. Utilizing the Hall effect principle, the converted signal can be directly acquired and received by various acquisition devices such as AD, DSP, PLC, and secondary instruments. They offer a sturdy structure, small size, long lifespan, easy installation, quick response time, wide frequency bandwidth (generally 0-350kHz), wide current measurement range, high accuracy, strong overload capacity, good linearity, and strong anti-interference capabilities.
Technical Specifications:
- Response Time: ≤2μs
- Bandwidth: 350kHz
- Magnetic Offset Current: 30μA
- Input Overload Capacity: Maximum input range value of 2 times, can resume normal operation
- Dielectric Strength: 3.5kV/50Hz/1min
- Operating Temperature: -40℃ to 85℃
With the rapid advancements in sensor technology and communication technology, the integrated monitoring system for power cable tunnels will undoubtedly become an indispensable part of smart grid construction. Fluxgate current sensors can comprehensively monitor the electrical output of cable lines in real-time, understand the operation status of cables, fundamentally prevent cable accidents, and ensure the safe and reliable operation of cables. This system demonstrates high reliability and timeliness, significantly enhancing the operational capability of tunnel cables.
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