Relay Close-Time Monitoring for Welded Contact Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing relay systems struggle to detect single welded double break contacts, which can lead to catastrophic failures due to internal line-to-line short circuits, as the welded contact closes before the other, causing damage to the controller.
Innovation Solution
A method and system that measure the close time of each relay to identify welded contacts by comparing the close time of each relay to a threshold, determined based on the average close time of non-welded relays, allowing early detection and prevention of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If relay contacts are monitored using traditional methods, then the system structure remains simple, but welded contacts cannot be detected reliably
Solution Approach 1:
The relay system uses its own operational characteristics (close time) to detect welded contacts. The controller measures the close time of each relay and compares it against threshold values, allowing the system to self-diagnose contact welding without requiring external specialized detection equipment.
Solution Approach 2:
The invention detects welded contacts by monitoring changes in the close time parameter of relays. When a contact becomes welded, the close time changes characteristically, and the controller identifies this by comparing measured close times against predetermined thresholds, enabling detection through parameter analysis rather than structural modification.
2Measurement precision
If close time measurement is used to detect welded contacts, then detection accuracy improves, but measurement precision requirements increase
Solution Approach 1:
The controller is pre-configured with threshold values for close time measurements that distinguish normal relay operation from welded contact conditions. By establishing these reference values in advance, the system can reliably detect welded contacts through simple comparison of measured close times against the predetermined thresholds.
Data Source
AI summary
A system includes a relay system and a controller. The relay system includes a plurality of relays. The controller is configured to transmit a close signal to a first relay and a second relay of the plurality of relays. The close signal is configured to close the first contact and the second contact of each of the first relay and the second relay. The controller is also configured to measure a first close time between the transmission of the close signal to the first relay and a time when the first relay closes, and to measure a second close time between the transmission of the close signal to the second relay and a time when the second relay closes. The controller is further configured to determine whether an electrical weld exists in the first relay or the second relay, based on the first and second close times.