Protective Fuse Failure Detection Using Existing Current Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for detecting failures in protective fuses require complex circuitry and additional wires, increasing the risk of undetected failures and compromising operational safety in electrical distribution systems.
Innovation Solution
A method and apparatus that utilize a current sensor to measure electrical current through the fuse, determining failure indicators such as thermal energy or current thresholds to automatically detect fuse failures, eliminating the need for additional wires and simplifying the detection process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage drop measurement method is used to detect fuse failure, then detection capability is achieved, but device complexity and wiring requirements increase
Solution Approach 1:
The invention extracts the detection function from a separate measurement circuit and integrates it into the existing current sensor element. By using the current sensor that already measures current for protection purposes, the fuse failure detection capability is obtained without adding separate measurement wires or complex circuitry. The control unit processes the existing current measurement data to determine fuse integrity.
Solution Approach 2:
The current sensor element is made multi-functional by using it for both its original purpose (current measurement for overload/short-circuit protection) and the new purpose (fuse failure detection). The same sensor and processing unit detect both abnormal current conditions and fuse interruptions, eliminating the need for dedicated detection hardware and reducing overall system complexity.
2Reliability
If additional wires are connected on both sides of the protective fuse for potential measurement, then fuse failure detection is enabled, but the probability of undetected failures increases due to wire interruption risk
Solution Approach 1:
The invention removes the requirement for additional measurement wires by extracting the detection function from a separate voltage measurement system. The fuse failure detection is achieved by monitoring current flow through the existing current sensor, eliminating physical wires that could be interrupted and cause false negatives.
Solution Approach 2:
The control unit acts as an intermediary that processes current measurement data to infer fuse status. Instead of directly measuring voltage across the fuse with separate wires, the control unit analyzes the current signal already present in the circuit, using the current sensor as an intermediary measurement point that does not require additional wiring.
3Device complexity
If simple current measurement is used, then device complexity is reduced, but detection speed and reliability may be compromised
Solution Approach 1:
The current sensor element continuously measures current flow to provide protection functionality, and this continuous measurement simultaneously provides continuous fuse failure detection. The control unit continuously monitors the current signal, enabling immediate detection of fuse interruptions without requiring additional measurement cycles or complex processing, thus achieving fast detection with simple circuitry.
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 reliable and fast detection of fuse failures, operating effectively in harsh environments with a detection time of less than one millisecond, enhancing operational reliability and safety without increasing circuit complexity.
Implementation Method 1
measuring an electrical current, Im, flowing through the protective fuse in a current path to said load by means of a current sensor element
Implementation Method 2
determining a thermal energy generated in the protective fuse depending on the measured electrical current
Data Source
AI summary
A method for detection of a fuse failure of a protective fuse used to protect an associated load against overcurrent and/or against overload includes the steps of: measuring electrical current flowing through the protective fuse in a current path to the load by means of a current sensor element; determining one or more failure indicators adapted to indicate a possible failure of the protected fuse on the basis of the measured electrical current; and detecting automatically a failure of the protective fuse if the determined at least one failure indicator indicates a possible failure of the protective fuse and if the electrical current stopped to flow through the protective fuse or is below a predefined current threshold value.