AFCI Noise Generation Circuit for Startup-Only Self-Checking
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Solution Overview
Problem
The constant generation of noise signals by the noise generation circuit in the self-checking circuit of an AFCI affects the normal functioning of both the AFCI and the photovoltaic inverter, regardless of whether the self-checking circuit is testing the detection circuit's functionality.
Innovation Solution
A power switch module controls the noise generation circuit to generate noise signals only when a self-checking instruction is received, ensuring the noise generation occurs only during system initialization and not during normal operation, using components like PMOS transistors and Zener diodes to manage power supply and signal generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the noise generation circuit constantly generates noise signals for self-checking, then the detection circuit functionality can be continuously tested, but the noise signals affect the normal operation of the AFCI and photovoltaic inverter
Solution Approach 1:
The patent implements periodic self-checking by controlling the noise generation circuit to generate noise signals only at specific intervals (e.g., during system startup or at predetermined time intervals) rather than continuously. The control circuit receives self-checking instructions and activates the noise generation circuit accordingly, allowing the detection circuit to be tested periodically without causing continuous interference to the AFCI and photovoltaic inverter operation.
2Adaptability or versatility
If the noise generation circuit generates noise signals during normal operation, then the self-checking function is continuously available, but the AFCI and photovoltaic inverter cannot work normally
Solution Approach 1:
The system performs self-checking periodically rather than continuously. The control circuit is configured to activate the noise generation circuit only during predetermined time intervals or upon receiving specific self-checking instructions, ensuring that the AFCI and photovoltaic inverter can operate normally during non-checking periods while still maintaining the capability to test detection circuit functionality when needed.
Solution Approach 2:
The patent implements self-checking at predetermined times such as during system startup before normal operation begins. This preliminary action allows the detection circuit to be tested in advance, ensuring its functionality is verified before the AFCI and photovoltaic inverter commence normal operation, thus avoiding interference with productive work while maintaining system reliability.
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 solution ensures that the AFCI and photovoltaic inverter operate normally by preventing noise signals from impacting components during regular operation, thereby improving their efficiency and reliability.
Implementation Method 1
The noise signal generated by the noise generation circuit has a spectrum characteristic the same as that of an arc noise signal
Implementation Method 2
a power switch module controls, only when receiving a self-checking instruction, the noise generator of the noise generation circuit to generate a noise signal
Data Source
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AI summary
This application provides a noise generation circuit, a self-checking circuit, an AFCI, and a photovoltaic power generation system. The noise generation circuit includes a power switch module, a noise generator, and a capacitor, where the noise generator is connected to both the power switch module and the capacitor; the power switch module is configured to control, according to a self-checking instruction, whether the noise generator generates a noise signal; and the capacitor is configured to filter out a direct current component in the noise signal when the noise generator generates the noise signal. According to the noise generation circuit, the self-checking circuit, the AFCI, and the photovoltaic power generation system that are provided in this application, no noise signal is generated in a non self-checking time, so that no impact is imposed on a component in the AFCI in a working state or a component in a photovoltaic inverter of the AFCI, thereby ensuring normal working of the AFCI and the photovoltaic inverter.