Active detecting type fiber grating cable tunnel security and protection monitoring system

Abstract

The invention relates to an active detecting type fiber grating cable tunnel security and protection monitoring system. The active detecting type fiber grating cable tunnel security and protection monitoring system consists of a pump light source, a first coupler, a hydrophone, a low-frequency vibration sensor, an opto-isolator, a second coupler, a non-equilibrium Mach-Zehnder interferometer, a wavelength selector, a photoelectric detector, a piezoelectric transducer (PZT) driver, a digital acquisition device, a program gain control (PGC) phase demodulator and a computer provided with an alarm information managing platform. The active detecting type fiber grating cable tunnel security and protection monitoring system has the advantages of adopting a fiber grating sensor technology, being anti-electromagnetic-interference, electrically insulating, corrosion-resisting, good in safety, long in service life and easy to network, achieving remote distributed measurement and the like, has high sensitivity of an interference type demodulating system, can monitor sound inside and outside a cable tunnel and vibration produced by invaded people, reduces false alarm rate, improves identification on alarm events and operation safety supervision level of a power system and provides a safe and effective management mode for a power transmission system.

Description

technical field [0001] The invention relates to a comprehensive security monitoring system for cable tunnels based on active detection fiber grating sensing technology, which belongs to the field of security monitoring systems. Background technique [0002] The use of cable tunnels is an important measure to meet the high load density and cable-based power supply requirements in central urban areas, effectively guarantee the transmission capacity of power channels and improve the utilization of channel resources. With the rapid development of urban power cable tunnels, expensive equipment and long-distance space in cable tunnels require more sensitive, comprehensive and intelligent security systems to ensure the safety of cable tunnels and prevent dangerous accidents. [0003] Chinese patent CN201110423977.0 discloses a fiber grating perimeter anti-intrusion system, which can be networked on a large scale and accurately determine the mode and position of vibration signals, b...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent CN201110423977.0 discloses a fiber grating perimeter anti-intrusion system, which can be networked on a large scale and accurately determine the mode and position of vibration signals, but the resolution of passive fiber gratings is difficult to detect weak signals, such as Sound and Seismic Waves

Chinese patent CN101566497A discloses a distributed optical fiber vibration sensing system based on phase detection and optical time domain reflection. As an interferometric sensing system, its sensitivity is high, but its positioning accuracy is poor, signal analysis is complicated, and it is easy to be interfered

Images