Power Cord Leakage Detection With Open-Circuit Self-Test
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Solution Overview
Problem
Conventional LCDI devices fail to detect open circuit conditions in the leakage current detection lines, leading to a hidden threat of fire hazards and other safety issues.
Innovation Solution
The proposed LCDI device includes a switch module, a leakage current detection module with two dedicated detection lines, and a drive module with semiconductor devices and solenoids. This configuration allows the device to detect leakage currents and self-test fault signals, enabling it to disconnect the power supply when open circuits or leakage currents are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional LCDI devices are used without self-test functionality, then the device complexity is reduced, but the reliability of leakage current detection is compromised due to undetected open circuit conditions
Solution Approach 1:
The patent implements self-test functionality that performs preliminary checks on the leakage current detection lines before normal operation. The self-test module actively detects open circuit conditions in advance, ensuring the detection system is functional before actual leakage detection is needed, thereby resolving the contradiction between reliability and complexity.
Solution Approach 2:
The patent incorporates feedback mechanisms where the self-test module continuously monitors the detection lines and provides feedback about their operational status. This feedback system enables the device to recognize when detection lines are faulty and adjust its operation accordingly, improving reliability through continuous verification without requiring overly complex additional hardware.
2Measurement precision
If separate detection lines for hot and neutral wires are implemented, then the measurement precision of leakage current detection is improved, but the device complexity increases
Solution Approach 1:
The patent divides the leakage current detection function into separate detection lines for the hot wire and neutral wire. Each detection line independently monitors its respective wire, providing precise measurement of leakage currents on each conductor. This segmentation improves measurement precision by isolating detection functions while maintaining manageable complexity through modular design.
Solution Approach 2:
The patent designs the detection system where the same basic detection circuitry and components are used for both hot and neutral wire monitoring. The self-test module and processing logic handle both detection lines universally, reducing the need for entirely separate systems and thereby limiting the increase in device complexity despite the enhanced measurement precision from separate lines.
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 device effectively detects leakage currents and open circuit conditions in the leakage current detection lines, ensuring safe disconnection of power supply and preventing potential fire hazards.
Implementation Method 1
the at least one solenoid is configured to, in response to the current flowing through it, generate an electromagnetic force to drive the switch module to disconnect the electrical connection
Data Source
AI summary
A leakage current detection and interruption device for a power cord includes a switch module that controls an electrical connection of first and second power supply lines because input and output ends; a leakage current detection module, including first and second leakage current detection lines, which respectively detect leakage current signals on the first and second power supply lines and generate self-test fault signals in response to the first and second leakage current detection lines having an open circuit; and a drive module including at least one solenoid, a first semiconductor device forming a first current path from the first to the second power supply line when conductive, and a second semiconductor device forming a second current path from the second to the first power supply line when conductive, to supply current to the solenoid which in turn drives the switch module to disconnect the electrical connection.