Multi-Band Arc Detector Filtering Switching Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing arc detectors struggle to accurately distinguish arcs from switching noise and inverter noise, leading to false detections and the inability to utilize high-speed analog-to-digital converters efficiently.
Innovation Solution
An arc detector with a multi-frequency band detection function that uses low-pass, band-pass, and high-pass filters to divide the arc frequency band into multiple detection bands, minimizing false detections and reducing the need for expensive high-speed analog-to-digital converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a general overcurrent circuit breaker or earth leakage circuit breaker is used to detect faults, then the device is simple and inexpensive, but it cannot detect series arc faults because the fault current magnitude is within normal operating range
Solution Approach 1:
The arc frequency band is divided into multiple sub-bands using band-pass filters, allowing detection of arc characteristics in different frequency ranges. This segmentation enables precise identification of arc faults while filtering out noise in specific frequency bands, resolving the contradiction between detection accuracy and system complexity.
Solution Approach 2:
The invention changes the detection parameter from current magnitude (which is within normal range for series arcs) to frequency domain characteristics. By analyzing the frequency spectrum of current signals and identifying arc-specific frequency patterns, the system achieves accurate arc detection without requiring complex high-speed ADCs.
2Measurement precision
If high-speed analog-to-digital converters are used to detect arcs accurately, then arc detection precision is improved, but manufacturing cost increases due to expensive components
Solution Approach 1:
Instead of using a single high-speed ADC to capture the entire frequency spectrum, the invention segments the frequency band using analog band-pass filters. Each filter processes a specific frequency range, allowing the use of lower-speed, lower-cost ADCs or even purely analog comparison circuits for each band, significantly reducing overall system cost while maintaining detection precision.
Solution Approach 2:
The invention extracts only the relevant arc frequency components from the full spectrum using band-pass filters, discarding irrelevant frequency bands where noise occurs. This extraction approach allows simpler detection circuits to process only the necessary information, avoiding the need for expensive high-speed conversion of the entire signal bandwidth.
3Reliability
If the entire arc frequency band is monitored as a single band, then detection coverage is complete, but switching noise and inverter noise cause false detections
Solution Approach 1:
The frequency band is segmented into multiple sub-bands, each processed independently. This allows the system to identify arcs that exhibit characteristic patterns across multiple bands while rejecting noise that appears in only one band, significantly improving detection reliability and reducing false positives from switching and inverter noise.
Solution Approach 2:
Different frequency bands are assigned different detection characteristics and threshold settings based on their specific noise environments. By optimizing detection parameters locally for each band rather than using a single global threshold, the system achieves high reliability in each band while maintaining overall system robustness against various noise sources.
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
Enhances arc detection accuracy by excluding switching noise and power supply noise, reduces manufacturing costs, and ensures continuous monitoring of power quality by processing arcs in separate frequency bands.
Implementation Method 1
divides a frequency band into a plurality of detection bands and detects an arc by applying a low-pass filter, at least one band-pass filter, and a high-pass filter for frequency bands where generation of an arc is expected
Data Source
AI summary
The present invention proposes an arc detector having a multi-band frequency detection function, which divides an arc frequency band using multiple band-pass filters and detects whether or not an arc occurs in each of the divided frequency bands, thereby eliminating switching noise or power supply noise that mainly occurs in a certain frequency band, and consequently increasing the accuracy of arc detection. In addition, the arc detector of the present invention may minimize the use of expensive analog-to-digital converters and increase the accuracy of arc detection through overlapping area detection.