Power Distribution System with Line Testing for Fault Detection
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Solution Overview
Problem
Conventional power distribution systems, including those with Ground Fault Interrupters, fail to adequately protect against electrical faults that can lead to fires or electrocution, particularly in scenarios where a person comes into contact with both live and neutral conductors, as they do not detect cross-line faults effectively and can allow for electrical shocks below the threshold to cause cardiac arrest or ignite materials.
Innovation Solution
A power distribution system that monitors energy transfer by periodically isolating the source and load and measuring voltage decay rates to detect faults, using capacitors to store voltage and comparing pre- and post-isolation measurements to determine if a fault has occurred, and controlling switches to prevent energy transfer during fault conditions, thereby preventing both electrocution and fires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional circuit breakers and GFIs are used for protection, then basic overcurrent and ground fault protection is provided, but cross-line faults and fires from loose connections are not detected
Solution Approach 1:
The system performs preliminary testing of the transmission line by isolating it from both source and load, then measuring voltage decay characteristics before allowing normal power transfer. This advance detection identifies faults including cross-line faults that traditional devices miss, preventing them from causing fires or electrocution during operation
Solution Approach 2:
A testing circuit acts as an intermediary between the power source and load, inserting itself during the isolation period to measure voltage decay and detect faults. This intermediary testing mechanism enables detection of cross-line faults and high-resistance connections without requiring complex continuous monitoring during power transfer
2Object-affected harmful factors
If GFI protection is used, then electrocution protection is provided for contact with line and ground, but protection is lost when contact occurs between line and return path
Solution Approach 1:
The system performs preliminary testing of the transmission line by isolating it from both source and load, then measuring voltage decay characteristics before allowing normal power transfer. This advance detection identifies faults including cross-line faults that traditional devices miss, preventing them from causing fires or electrocution during operation
Solution Approach 2:
The system continuously monitors voltage decay characteristics during isolation periods and provides feedback on line conditions. This feedback mechanism detects changes in line impedance that indicate faults, enabling the system to identify dangerous conditions before they cause harm and to adapt protection strategies accordingly
3Productivity
If high current is allowed to transfer for productivity, then power delivery is improved, but risk of fire and electrocution increases
Solution Approach 1:
The system performs preliminary testing of the transmission line by isolating it from both source and load, then measuring voltage decay characteristics before allowing normal power transfer. This advance detection identifies faults including cross-line faults that traditional devices miss, preventing them from causing fires or electrocution during operation
Solution Approach 2:
The system implements periodic isolation and testing cycles during power distribution, briefly disconnecting to perform safety checks on transmission line conditions. These periodic tests measure voltage decay characteristics to detect faults, ensuring continuous safety monitoring without significantly interrupting overall power delivery productivity
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 system effectively detects and prevents both in-line and cross-line faults, reducing the risk of electrocution and fire by ensuring the energy transfer parameters remain below lethal levels, providing enhanced safety over traditional protection methods.
Implementation Method 1
Capacitor Cload is electrically connected to the load terminals. The capacitor stores the voltage present on load terminals 32a, 32b that existed just prior to the moment that S1 is opened
Implementation Method 2
During normal conditions, when S1 is opened, the voltage across capacitor Cload will decay as it discharges through Rsrc and into the load
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
A power distribution system for regulating energy transfer from a source includes a source controller responsive to a source sensor that provides feedback including a signal indicative of the voltage across the source terminals; a source disconnect device responsive to a control signal from the source controller for electrically connecting or disconnecting the source from the source terminals, wherein the source controller interrupts the supply of power by opening the source disconnect device when voltage is measured across the source terminals; a load disconnect device for electrically decoupling the load from the load terminals; and a logic device in the source controller for determining whether the source disconnect device is to be opened to interrupt the electrical connection between the source and source terminals based on a predetermined set of conditions including whether the change in voltage across the source terminals in respect to time falls outside a predetermined range.