Fault Detection System Using DC Bus Sensor
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Solution Overview
Problem
Existing fault detection systems for power electronics face challenges in improving response time, reducing complexity, and increasing sensitivity and selectivity to faults, particularly in motor drives with input transformers, which require numerous sensors and increase costs and complexity.
Innovation Solution
A fault detection system that includes sensors to measure electrical characteristics of AC power at multiple points in the system, a DC bus sensor, and a controller to determine fault conditions by scaling and comparing measurements, allowing for efficient detection of faults such as current imbalances and transformer malfunctions, and transmitting interrupt signals to protective devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If numerous sensors are used on primary and secondary windings of transformer, then fault detection sensitivity is improved, but system complexity and cost increase
Solution Approach 1:
The patent extracts the fault detection function from multiple sensors distributed across primary and secondary windings, concentrating it into a single sensor on the secondary side. This extraction eliminates the need for numerous sensors while maintaining fault detection capability through mathematical relationships between electrical quantities.
Solution Approach 2:
The single sensor on the secondary winding serves multiple functions: detecting faults in the primary winding, detecting faults in the secondary winding, and providing data for calculating multiple electrical quantities (currents, powers) through mathematical relationships. This multi-functionality replaces what previously required multiple dedicated sensors.
2Measurement precision
If numerous sensors are used on primary and secondary windings of transformer, then fault detection sensitivity is improved, but cost increases
Solution Approach 1:
The patent extracts the fault detection function from multiple sensors distributed across primary and secondary windings, concentrating it into a single sensor on the secondary side. This extraction eliminates the need for numerous sensors while maintaining fault detection capability through mathematical relationships between electrical quantities.
3Measurement precision
If multiple sensors are used to detect faults, then fault detection selectivity is improved, but response time increases due to processing multiple inputs
Solution Approach 1:
The patent extracts the fault detection function from multiple sensors distributed across primary and secondary windings, concentrating it into a single sensor on the secondary side. This extraction eliminates the need for numerous sensors while maintaining fault detection capability through mathematical relationships between electrical quantities.
Solution Approach 2:
The patent replaces the physical system of multiple sensors with a mathematical model that calculates primary winding current and power using secondary side measurements. This substitution reduces physical components while maintaining detection accuracy through computational relationships.
Data Source
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AI summary
Unique systems, methods, techniques and apparatuses of a fault detection system are disclosed herein. One exemplary embodiment is a fault detection system comprising a protected device including a DC bus structured to receive AC power and provide AC power; a DC bus sensor structured to measure an electrical characteristic of the DC bus; at least one input sensor structured to measure an electrical characteristic of the AC power received by the protected device; at least one output sensor structured to measure the electrical characteristic of the AC power provided by the protected device; and a monitoring device configured to receive measurements from the DC bus sensor, at least one input sensor, at least one output sensor and determine the existence of a fault condition which originates within the protected device using the measurements of the DC bus sensor, at least one input sensor, and at least one output sensor.