Arc Detector Using Power Spectrum Section Value for Noise Immunity
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Solution Overview
Problem
Existing arc detectors in photovoltaic power generation systems struggle to accurately detect arcs when noise is generated in frequency bands different from the preset frequency band, and they face challenges in safely and easily measuring voltage due to the need for high-voltage sensors, which can be hazardous.
Innovation Solution
An arc detector that includes a current sensor, a power spectrum conversion unit, a section value obtaining unit, and an arc determination unit, which divides the power spectrum into regions, selects a section value excluding the maximum region value, and determines the presence of an arc based on this value, allowing for detection independent of noise frequency changes and reducing the need for high-voltage sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage measurement is used for arc detection, then arc detection capability is improved, but safety risk increases due to need for high-voltage sensors
Solution Approach 1:
The patent uses current as an intermediary measurement parameter instead of directly measuring voltage. The current sensor acts as a safe intermediary that provides information about arc conditions without requiring high-voltage sensing capabilities, thus maintaining detection accuracy while eliminating safety risks associated with high-voltage sensors
2Object-affected harmful factors
If preset frequency band filtering is used to eliminate noise, then noise interference is reduced, but detection accuracy deteriorates when noise frequency changes
Solution Approach 1:
The patent dynamically adjusts the frequency band for arc detection based on the actual noise characteristics present in the system. Instead of using a fixed preset frequency band, the system identifies the noise frequency components and adapts the detection band accordingly, allowing it to maintain high detection accuracy even when noise frequencies change due to different power conditioner types or operating conditions
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
The solution effectively reduces the influence of noise from external devices and enables easy and accurate arc detection in photovoltaic power generation systems, improving safety and reliability by using current measurements rather than voltage.
Implementation Method 1
a current sensor that detects an output current from a distributed direct-current power supply
Implementation Method 2
a power spectrum conversion unit that converts the output current from the current sensor to a power spectrum
Data Source
AI summary
An arc detector includes a current sensor, a power spectrum conversion unit that converts an output from the current sensor to a power spectrum, a section value obtaining unit that divides an arc measurement section for the power spectrum into a plurality of regions, and obtains, from region values for the plurality of regions excluding a maximum one of the region values, a region value to be a section value of the arc measurement section, and an arc determination unit that determines a presence of an arc by comparing the section value with a threshold.