Acoustic Fault Localization Using Magnetic Reference Signals
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Solution Overview
Problem
Existing acoustic signal pinpointing methods for locating faults in underground electrical lines are impaired by external noise sources like wind, rain, and road traffic, which interfere with the detection of ground noise, making precise localization challenging.
Innovation Solution
The method involves using a computing unit to synchronize and process acoustic impulses detected by an acoustic sensor with associated magnetic impulses, employing an averaging algorithm and a motion detector to suppress interference without distorting the useful signal, utilizing the magnetic pulse as a reference for signal processing and storage in a memory unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic sensor is used to detect ground noise for fault location, then fault localization capability is enabled, but external acoustic noise (wind, rain, road traffic) impairs or prevents precise pinpointing
Solution Approach 1:
The patent introduces magnetic field sensor signals as an intermediary reference to filter and identify genuine arcing events from background acoustic noise. The magnetic field component serves as a mediator that validates which acoustic signals are actually related to fault arcing, enabling precise fault localization despite external acoustic interference.
Solution Approach 2:
The patent changes the analysis parameters by incorporating magnetic field signal characteristics (amplitude, duration, waveform) alongside acoustic signal parameters. This multi-parameter approach transforms the single acoustic parameter analysis into a combined acoustic-magnetic parameter space, allowing differentiation between genuine fault signals and environmental noise.
2Object-affected harmful factors
If acoustic signals are processed to suppress interference, then noise reduction is achieved, but the useful signal may be distorted and falsify the acoustic hearing impression
Solution Approach 1:
The patent employs feedback mechanisms where the magnetic field sensor continuously monitors and provides reference signals that feed back into the acoustic signal processing chain. This feedback loop allows real-time identification and preservation of genuine arcing signal characteristics while suppressing noise, maintaining signal authenticity through continuous validation against magnetic field references.
Solution Approach 2:
The system performs preliminary identification of genuine arcing events using magnetic field detection before applying acoustic signal processing. By pre-identifying valid signal time windows through magnetic field correlation, the system prepares the acoustic signal processing to only enhance and preserve signals within these validated windows, preventing distortion of useful signals.
3Object-affected harmful factors
If multiple acoustic impulses are stored and processed in memory, then signal averaging can suppress stochastic noise, but device complexity increases
Solution Approach 1:
The patent implements periodic action by repeatedly storing and processing acoustic impulses synchronized to the power frequency (50/60 Hz) of the electrical system. The arcing occurs periodically at each half-cycle, and the system captures multiple periodic impulses, averages them, and suppresses stochastic noise that does not repeat with the same periodicity, achieving noise reduction through rhythmic sampling and averaging.
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
This approach effectively reduces acoustic interference, allowing for clearer identification of arcing noise and improved localization of faults in underground cables by using the magnetic pulse as a reference for signal processing, maintaining audio quality and precision in fault detection.
Implementation Method 1
acoustic sensor 8 as well as a display unit... acoustic pulse, which is caused by each arcing at the fault location, propagates in the ground and is detected as a signal 6 at the earth's surface
Implementation Method 2
receiving unit 9 consists, in a known manner, of a magnetic field sensor 7 and an acoustic sensor 8... magnetic field sensor 7... magnetic pulses in case of arcing
Implementation Method 3
the arithmetic unit uses an averaging algorithm as an algorithm for interference suppression of the acoustic signals... use the time-limited useful signals by means of an algorithm using the magnetic pulse as the starting point for signal processing and to essentially suppress the acoustic interference signals
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The arrangement has a portable receiver (9) comprising an acoustic sensor (8) and a magnetic field sensor (7) for detecting magnetic impulses of arcs formed at a fault point. Acoustic impulse is supplied to a memory (10) and compared with previously stored acoustic impulse by a processing algorithm in a processing unit (11). Start time points of the acoustic impulses are synchronized by magnetic impulses, where result from the computing unit is supplied to an evaluating unit i.e. audio channel. A movement detector is attached to the acoustic and magnetic field sensors.