Solar DC Cable Safety Indicator with Threshold Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solar energy systems lack a reliable method to indicate the state of high voltage cables to workers and first responders during rapid shutdown sequences, posing safety risks due to unknown voltage and current levels.
Innovation Solution
An indicator device is coupled to DC wire lines, featuring current and voltage sensors that compare measured levels to threshold values, providing a visual output through LEDs or a display to indicate safe or hazardous conditions, ensuring workers can assess the safety of the cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If rapid shutdown circuitry is used to remove power on high voltage cables, then safety during fire emergencies is improved, but the ability to know the state of cables with certainty is lost
Solution Approach 1:
The patent implements feedback by continuously monitoring voltage and current levels on DC cables and providing real-time visual status indicators. After rapid shutdown is initiated, the system continues to monitor and display whether hazardous levels remain present, giving workers feedback on the actual state of cables rather than assuming shutdown was successful.
Solution Approach 2:
The patent introduces an intermediary monitoring device that sits between the rapid shutdown circuitry and the workers. This device translates electrical parameters (voltage, current) into visual information (status indicators), serving as a mediator that provides indirect but reliable information about cable safety without requiring workers to directly measure electrical parameters.
2Reliability
If visual status indicators are added to indicate cable safety, then worker awareness of hazardous conditions is improved, but device complexity increases
Solution Approach 1:
The patent extracts the monitoring and indication functions from the main rapid shutdown system into a separate, dedicated indicator device. This allows the core shutdown functionality to remain simple while adding safety indication capabilities independently. The indicator device can be installed on existing DC cables without modifying the inverter or shutdown circuitry.
Solution Approach 2:
The patent applies local quality by placing status indicators at specific locations where workers need information (near DC cables, disconnects, and equipment). Rather than making the entire system complex, only local points of interaction include visual indicators, keeping the overall system simple while providing targeted safety information where needed.
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 provides real-time visual feedback on the safety of high voltage DC wire lines, enabling workers to safely navigate environments with active solar energy systems by clearly indicating harmful voltage and current levels, enhancing safety during emergencies.
Implementation Method 1
at least one current sensor for measuring a current level on each of the positive and negative DC wire lines
Implementation Method 2
voltage sensors for measuring a first voltage across the positive and negative DC wire lines, a second voltage across the positive DC wire line and a ground terminal, and a third voltage across the negative DC wireline and the ground terminal
Implementation Method 3
A circuit block compares the measured current level on each of the positive and negative DC wire lines to one or more threshold current levels, and further compares the measured first, second and third voltages to one or more threshold voltage levels
Implementation Method 4
A visual indicator receives the output signal from the circuit block, and in response provides a visual indication of whether voltage and/or current levels on the positive and negative DC wire lines are at levels that harm humans
Data Source
AI summary
An indicator device includes a housing configured to be coupled to positive and negative DC wire lines that supply power from an energy generation source to an inverter. The indicator device further includes a current sensor for measuring a current level on the positive and negative DC wire lines, and voltage sensors for measuring a first voltage across the positive and negative DC wire lines, a second voltage across the positive DC wire line and a ground terminal, and a third voltage across the negative DC wireline and the ground terminal. A circuit block compares the measured current level to one or more threshold current levels, and further compares the measured first, second and third voltages to one or more threshold voltage levels, and in response provides an output signal. A visual indicator receives the output signal from the circuit block, and in response provides a visual indication of whether voltage and current levels on the positive and negative DC wire lines are at levels that may harm humans.