Photovoltaic Cell Fault Detection With Stable Output Power
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Solution Overview
Problem
Existing photovoltaic cell detection methods cause significant power fluctuations in photovoltaic systems, affecting grid connection quality due to rapid switching between short-circuit and open-circuit working points, which is detrimental to the stability and efficiency of the power generation system.
Innovation Solution
A method that maintains a stable output power by controlling photovoltaic cells to operate at two voltages with minimal power difference, allowing infrared image capture to detect faults without causing large power fluctuations, using a control device to manage the output power through DC/DC conversion modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the photovoltaic cell is switched between short-circuit and open-circuit working points for detection, then the detection accuracy is improved, but the power fluctuation increases drastically
Solution Approach 1:
The patent changes the working voltage parameters of the photovoltaic cell from extreme points (short-circuit and open-circuit) to two specific voltages (first voltage and second voltage) that are both greater than 0 and result in positive output power. This parameter change allows detection to be performed while maintaining stable power output, resolving the contradiction between detection accuracy and power fluctuation.
2Reliability
If the photovoltaic cell works at extreme working points for detection, then the fault detection capability is enhanced, but the grid connection quality deteriorates
Solution Approach 1:
The patent changes the operating voltage parameters from extreme working points to controlled voltage levels (first and second voltages) that maintain positive output power. This prevents the drastic power fluctuations that cause voltage flicker at grid connection points, thereby maintaining grid connection quality while still enabling effective fault detection through infrared imaging.
3Stability of the object's composition
If the output power is reduced for detection purposes, then the system stability is improved, but the detection sensitivity decreases
Solution Approach 1:
The patent optimizes the voltage parameters to achieve a balance point where the output power remains stable (both first and second output powers are greater than 0 and their difference is within a preset threshold) while still maintaining sufficient detection sensitivity. The controlled voltage levels ensure stable power output without compromising the ability to detect faults through infrared imaging.
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 fault detection in photovoltaic cells without disrupting the system's power stability, ensuring consistent output and maintaining grid connection quality by minimizing power fluctuations during the detection process.
Implementation Method 1
When the photovoltaic cell receives light of a specific wavelength, an electron in a ground state in the photovoltaic cell absorbs a photon and enters an excited state, and emits infrared light when returning to the ground state in a short period of time.
Implementation Method 2
The photovoltaic module can convert energy of sunlight into electric energy.
Data Source
AI summary
A photovoltaic cell detection method includes determining a first output power working at a first voltage and a second output power working at a second voltage, where a difference between the first output power and the second output power is less than a power difference threshold, and where both the first output power and the second output power are greater than 0; controlling the photovoltaic cell to work at the first voltage, and obtaining first infrared image information of the photovoltaic cell; and controlling the photovoltaic cell to work at the second voltage, and obtaining second infrared image information of the photovoltaic cell, where both the first infrared image information and the second infrared image information are used to jointly detect whether the photovoltaic cell is faulty.