Induction Machine Rotor Anomaly Detection via Low-Frequency Signal Rectification

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Solution Overview

Problem

Current methods for detecting anomalies in the rotor of induction machines, such as broken rotor bars, are computationally intensive and require observation of frequency components close to the primary components, making them inefficient and costly for large machines.

Innovation Solution

A method and system that process signals from induction machines to obtain low-frequency signals, rectify them, and declare anomalies based on these rectified signals, using techniques such as instantaneous impedance computation and signal processing to reduce computational and memory storage requirements, allowing for on-line monitoring and early detection of rotor anomalies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency response analysis is used to detect rotor anomalies, then detection accuracy is improved, but computational complexity and memory storage requirements increase

Engineering Contradiction:
Improveanomaly detection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential low-frequency components from the current signal that are directly related to rotor anomalies, rather than performing complete frequency response analysis. This selective extraction maintains detection accuracy while significantly reducing computational complexity and memory requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the current signal into different frequency components and focuses analysis only on the low-frequency segment that contains anomaly information. This segmentation allows the system to ignore high-frequency components, reducing overall computational burden while preserving detection capability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If complete frequency response analysis is performed, then anomaly detection capability is improved, but processing time increases

Engineering Contradiction:
Improveanomaly detection capabilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts only the low-frequency components containing anomaly information, eliminating the need to process the entire frequency spectrum. This extraction approach maintains reliable anomaly detection while dramatically reducing processing time for implementation in real-time monitoring systems.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If high computational resources are allocated for signal processing, then detection precision is improved, but cost and system complexity increase

Engineering Contradiction:
Improvedetection precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the necessary low-frequency signal components for anomaly detection, avoiding the need for complex computational resources. This approach achieves accurate detection with simpler, more cost-effective hardware and software implementations suitable for industrial environments.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS8473228B2Detection of rotor side anomaly in an induction machine
Publication Date: 2013.06.25 GE INFRASTRUCTURE TECH LLC
  • US8473228B2 patent drawing
  • US8473228B2 patent drawing
  • US8473228B2 patent drawing

AI summary

A method for detecting an anomaly in an induction machine includes obtaining or receiving a signal from the induction machine; processing the signal so as to obtain a low frequency signal, then rectifying the low frequency signal; and, declaring if the anomaly is present, based on the rectified low frequency signal. A system for detecting anomalies is also disclosed. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.