Partial Discharge Detection via Frequency Segmentation
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Solution Overview
Problem
Existing methods for detecting partial discharges in electrical machine windings face challenges in distinguishing between partial discharge signals and interference signals, particularly during online measurements, where interference from operational components and external sources complicates the detection process.
Innovation Solution
A method involving the simultaneous detection of electromagnetic measurement signals in partial discharge and interference frequency ranges, with defined time windows and criteria for distinguishing between partial discharge and interference signals, utilizing multiple sensors and signal processing techniques to enhance detection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If online measurement is performed during regular machine operation, then productivity is improved by avoiding downtime, but measurement precision deteriorates due to interference signals from operating components and external sources
Solution Approach 1:
The measurement system segments the frequency spectrum into multiple frequency ranges, with each range targeted by dedicated sensors or sensor groups. This allows selective monitoring of partial discharge signals in specific frequency bands while filtering out interference signals in other bands, thereby maintaining measurement precision during online operation.
Solution Approach 2:
Different sensors with specialized characteristics are deployed at different locations and frequency ranges. Each sensor is optimized for specific frequency bands where partial discharge signals are expected, while interference signals occur in different bands. This local specialization enables precise detection of partial discharge signals even in the presence of operational interference.
2Measurement precision
If multiple sensors are used to detect interference signals, then measurement precision is improved by distinguishing partial discharge from interference, but device complexity increases
Solution Approach 1:
The evaluation unit performs multiple functions: it processes signals from multiple sensors, identifies partial discharge signals, characterizes interference signals, and distinguishes between the two. This multi-functional approach consolidates what would otherwise require separate specialized devices, maintaining measurement precision while limiting the increase in device complexity.
Solution Approach 2:
Multiple sensors detecting different frequency ranges are merged into a unified evaluation system that processes all signals simultaneously. The evaluation unit combines the detection capabilities of individual sensors to achieve comprehensive signal differentiation, reducing the need for separate dedicated systems for each frequency range.
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 improves the reliability of partial discharge detection by effectively differentiating between partial discharge and interference signals, reducing false positives and enhancing measurement sensitivity, even in noisy operational environments.
Implementation Method 1
electromagnetic first measurement signals are detected in a partial discharge frequency range
Implementation Method 2
electromagnetic second measurement signals are detected in a disturbance frequency range
Data Source
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AI summary
The invention relates to a method and to a device (1) for detecting a partial discharge at a winding of an electrical machine. According to the invention, electromagnetic first measuring signals are detected in a partial discharge frequency range and electromagnetic second measuring signals are detected in an interference frequency range. Moreover, a time window around a first measuring signal is predefined, and an identification criterion is defined for a partial discharge signal and an interference signal criterion is defined for a second measuring signal. A determination is made as to a partial discharge when a first measuring signal is detected that meets the identification criterion and when, in the time window around the first measuring signal, no second measuring signal that meets the interference signal criterion is detected.