Active Shaft Grounding with Waveform Diagnostics

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Solution Overview

Problem

Current methods for diagnosing and predicting faults in turbine, generator, or motor shafts are inadequate as they rely on manual analysis, which is time-consuming and limited by the expertise of human operators, and do not effectively evaluate the shape of voltage and current waveforms, leading to potential equipment damage and outages.

Innovation Solution

An automated system that uses learning algorithms and waveform analysis to monitor and diagnose shaft voltage and current waveforms, applying counteracting voltages or currents to neutralize shaft voltage, and employing support vector machines and other mathematical models to identify faults and predict degradations by comparing waveforms to baseline and fault models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual analysis by human experts is used to evaluate waveform shape, then diagnostic expertise can be applied, but the system is unmonitored most of the time and response is delayed

Engineering Contradiction:
Improvewaveform analysis expertiseVSAvoidcontinuous monitoring capability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs self-diagnosis by automatically analyzing waveform shapes using embedded processors and algorithms, eliminating the need for continuous human expert intervention. The processor independently evaluates waveform characteristics, detects anomalies, and triggers alerts, enabling the system to monitor itself continuously without external expertise.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Manual expert analysis is replaced with automated electronic processing and algorithmic waveform evaluation. The system uses digital signal processing, pattern recognition algorithms, and automated diagnostic logic to substitute human expertise with machine-based analysis, enabling continuous unsupervised monitoring.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If standard electrical signal processing is used with simple voltage average and peak values, then the system is simple to operate, but waveform shape evaluation is not performed

Engineering Contradiction:
Improvesystem simplicityVSAvoidwaveform shape evaluation
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The waveform analysis is divided into distinct processing stages: initial signal acquisition, decomposition into characteristic parameters, shape feature extraction, and diagnostic evaluation. This segmentation allows the system to maintain operational simplicity while incorporating sophisticated waveform shape analysis through modular processing steps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from analyzing only scalar values (average and peak voltage) to evaluating the entire waveform shape by examining multiple dimensions simultaneously. This includes analyzing temporal patterns, frequency characteristics, and morphological features, adding analytical depth without compromising ease of operation through automated processing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If routine maintenance is performed to clean shaft and brushes, then grounding effectiveness is maintained, but equipment must be taken offline and maintenance costs increase

Engineering Contradiction:
Improvegrounding effectivenessVSAvoidequipment availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary detection of grounding degradation through continuous waveform monitoring and analysis. By identifying early signs of brush wear, contamination, or grounding effectiveness reduction, the system enables proactive maintenance scheduling that prevents catastrophic failures while optimizing maintenance timing to minimize equipment downtime.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors shaft voltage waveforms and provides feedback on grounding system health. This real-time feedback enables dynamic assessment of grounding effectiveness, allowing operators to determine when maintenance is actually needed based on measured conditions rather than fixed schedules, thereby maintaining reliability while improving availability.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS10539602B2Active shaft grounding system with diagnostic waveform analysis
Publication Date: 2020.01.21 SIEMENS ENERGY INC
  • US10539602B2 patent drawing
  • US10539602B2 patent drawing
  • US10539602B2 patent drawing

AI summary

A system that applies a counteracting voltage or current to a rotating shaft to minimize a grounding voltage signal of the shaft, measures and analyzes the counteracting signal, and provides expert system logic that compares prior learned waveforms and models of baseline, fault, and degradation waveforms to operational waveforms to determine and predict faults and degradation events. Self-learning logic analyzes the operational waveforms to look for changes, and finds or predicts fault and degradation events in relation to archived characteristics of earlier waveforms. It then adds characteristics of predictive waveforms to the database of model waveforms, and updates rules and thresholds in the expert logic based on the found predictors. It may further calculate and continuously refine a counteracting signal waveform to minimize the shaft grounding waveform.