Wavelet-Based OCT Fiber Break Detection for Relay Protection
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Solution Overview
Problem
Existing optical fiber break detection methods in optical current transducers (OCTs) based on current sampling values of a photodiode result in delayed detection, leaving relay protection apparatuses vulnerable to malfunctions.
Innovation Solution
Perform wavelet transform on multiple current sampling data of a photodiode to obtain detail coefficients, analyzing their change features to quickly determine the on/off state of the optical fiber, thereby reducing the occurrence of relay protection apparatus malfunctions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical fiber break detection is based on current sampling value remaining below threshold for a period of time, then detection can be performed, but detection timing is delayed and relay protection apparatus remains vulnerable to malfunction
Solution Approach 1:
The patent applies preliminary action by continuously monitoring the current sampling value and comparing it against a threshold in real-time, rather than waiting for the value to remain below threshold for a predetermined period. This allows the system to detect optical fiber breaks immediately when the current value exceeds the threshold, eliminating detection delays while maintaining reliability through continuous monitoring.
2Speed
If wavelet transform is performed on multiple current sampling data to obtain detail coefficients, then optical fiber break can be detected rapidly, but device complexity increases
Solution Approach 1:
The patent applies mechanics substitution by replacing complex real-time signal processing systems with a simpler threshold-based detection method. Instead of using wavelet transform and detailed coefficient analysis, the system uses straightforward current sampling and threshold comparison, significantly reducing processing complexity while maintaining rapid detection capability through continuous monitoring.
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 rapid detection of optical fiber breaks, preventing malfunctions in relay protection apparatuses by utilizing wavelet transform to identify changes in detail coefficients, ensuring timely intervention.
Implementation Method 1
a photodiode (PD) in the OCT
Implementation Method 2
The OCT operates based on the Faraday magneto-optic effect, which means that an external magnetic field can deflect linearly polarized light propagating along the direction of the magnetic field
Data Source
AI summary
An optical fiber break detection method includes: acquiring multiple current sampling data of a photodiode in an optical current transducer; respectively performing wavelet transform on the multiple current sampling data to obtain a detail coefficient corresponding to each of the current sampling data; and determining an on/off state of an optical fiber in the optical current transducer according to the detail coefficients corresponding to the multiple current sampling data. This solution achieves the detection of an optical fiber break within a relatively short time, thereby reducing the occurrence of malfunction in a relay protection apparatus in case that an optical fiber break occurs. An apparatus and the relay protection apparatus are configured for implementing the method.