Adjacent Switch Current Summation for Selective Power Shut-Off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power supply systems face challenges in accurately detecting and responding to overcurrent abnormalities, particularly ground faults, due to insufficient monitoring of current variations across multiple power sources, leading to unreliable switch shut-off mechanisms.
Innovation Solution
A switch shut-off device that calculates a total current by summing energization currents through adjacent switches in the electrical pathway and shuts off the pair of switches when the total current exceeds a threshold, ensuring accurate detection and appropriate shut-off in response to overcurrent abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only the energization current of a single switch is monitored, then the monitoring system remains simple, but the abnormality detection reliability is insufficient
Solution Approach 1:
The electrical pathway is segmented into multiple sections with switches S1-Sn, and current monitoring is segmented to measure I1 and In at different locations. This segmentation allows the system to detect abnormalities in specific segments without requiring monitoring of every single switch, thus improving reliability while controlling complexity.
Solution Approach 2:
The control device acts as an intermediary that calculates the total current It by combining measurements from multiple switches. Instead of directly monitoring all switches, the system uses the control device to process and aggregate current data, providing reliable abnormality detection through computational mediation rather than direct comprehensive monitoring.
2Reliability
If the switch shut-off mechanism shuts off all switches when an abnormality is detected, then overcurrent protection is ensured, but unnecessary power failures occur in unaffected loads
Solution Approach 1:
The system segments the electrical pathway into multiple independent sections controlled by different switches. When an abnormality is detected in one section, only the switches in that specific segment are shut off, while other segments continue to receive power. This selective shut-off approach maintains protection reliability while preserving power supply to unaffected loads.
Solution Approach 2:
The shut-off action is applied locally only to the switches involved in the abnormality (S1 and Sn when It exceeds threshold), rather than globally shutting off all switches. This local quality approach ensures that protection is applied precisely where needed, minimizing disruption to overall system productivity.
3Measurement precision
If the threshold current is set low for sensitive detection, then ground faults are detected early, but false alarms increase due to normal current variations
Solution Approach 1:
The system merges current measurements from multiple switches (I1 + In) to calculate the total current It. This combination approach enhances measurement precision by aggregating signals, making it more sensitive to ground faults while the comparative nature of the summation helps distinguish actual abnormalities from normal current variations, reducing false alarms.
Solution Approach 2:
The control device continuously monitors the total current It and compares it against the threshold value. When It exceeds the threshold, the system provides feedback by shutting off the relevant switches. This feedback mechanism allows for dynamic adjustment and verification, enabling sensitive detection while maintaining reliability through continuous monitoring and corrective action.
Data Source
AI summary
A switch shut-off device is applied to a power supply system equipped with a first power source and a second power source connected via an electrical pathway, and a plurality of switches provided in the electrical pathway and connected in series with each other. The switch shut-off device includes a calculation unit configured to acquire an energization current flowing through each of a pair of switches that are adjacent to each other in the electrical pathway, among the plurality of switches, and to calculate a total current that is a sum of the energization currents flowing to an intermediate point between the pair of switches, and a shut-off unit configured to shut off the pair of switches when the total current exceeds a threshold current.