Shunt Resistor Abnormality Detection Using a Shared Reference Path
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Solution Overview
Problem
Existing systems for detecting characteristic abnormalities in resistance elements, such as shunt resistors, are costly due to the need for multiple resistance elements and amplifier circuits, which increase with the number of current sensors.
Innovation Solution
An abnormality detection device that includes first resistance elements coupled to loads, a second resistance element connected to a power supply via a coupling node, and a control device to derive current values and detect abnormalities by comparing them with the second resistance element's current value, reducing the need for individual amplifiers and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple resistance elements and amplifier circuits are provided for each current sensor, then abnormality detection capability is improved, but device complexity and cost increase
Solution Approach 1:
Multiple first resistance elements are electrically coupled in parallel to share a common coupling node, allowing a single second resistance element and single amplifier circuit to monitor all first resistance elements simultaneously. This merging approach maintains abnormality detection capability while reducing the total number of components.
Solution Approach 2:
The second resistance element serves a universal function by being electrically coupled to the coupling node that aggregates currents from multiple first resistance elements. This single second resistance element performs the abnormality detection function for all first resistance elements, eliminating the need for individual second resistance elements for each first resistance element.
2Device complexity
If a single second resistance element is used for multiple first resistance elements, then device complexity is reduced, but measurement precision may deteriorate
Solution Approach 1:
The control device derives both the first current value (through the first resistance element) and the second current value (through the second resistance element), then compares these values to determine abnormalities. This feedback comparison mechanism ensures measurement precision is maintained even with reduced component count.
Solution Approach 2:
The coupling node acts as an intermediary that aggregates the currents from multiple first resistance elements and provides them to the second resistance element. This intermediary structure allows the single second resistance element to accurately measure the combined current, maintaining measurement precision while reducing device complexity.
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
This approach allows for effective detection of resistance element abnormalities while minimizing costs by using a single second resistance element for multiple first elements, maintaining current supply integrity.
Implementation Method 1
first resistance elements 42a, 42b, and 42c... a second resistance element 44... deriving a first current value of a current flowing through one or more of the first resistance elements... deriving a second current value of a current flowing through the second resistance element
Data Source
AI summary
An abnormality detection device includes: first resistance elements; a second resistance element; and a control device. The control device includes one or more processors, and one or more memories coupled to the processors. The processor is configured to execute processes including deriving a first current value of the current flowing through one or more the first resistance elements among the multiple first resistance elements, deriving a second current value of the current flowing through the second resistance element, and determining whether there is a characteristic abnormality in the first resistance element, based on a comparison result between the first current value and the second current value.