Partial Discharge Detection Using Time Interval Discrimination
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Solution Overview
Problem
Existing methods for discriminating partial discharge pulses from noise in electrical systems, particularly in DC systems, are complex and often require expensive hardware, and some techniques used in AC systems are not applicable to DC systems.
Innovation Solution
A processing apparatus and method that uses two detectors to measure the time interval between detection events of electromagnetic signals at different areas of an electrical object, comparing this interval to a threshold value to distinguish between partial discharge pulses and noise signals, allowing for effective discrimination without relying on phase-resolved techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase-resolved PD pattern method is used to discriminate PD from noise, then discrimination reliability is improved, but the method cannot be applied to DC systems where voltage is constant
Solution Approach 1:
The invention changes the discrimination parameter from phase angle (used in AC systems) to time interval of flight (ToF) between detectors. This parameter change enables the method to work in both AC and DC systems, as ToF is independent of voltage waveform characteristics. The time interval measurement replaces the phase-resolved approach, allowing universal application across different electrical system types.
2Measurement precision
If waveform analysis with feature extraction is used to discriminate PD from noise, then discrimination accuracy is improved, but hardware complexity and cost increase
Solution Approach 1:
The invention extracts only the essential timing information (time interval of flight) from the detected signals, discarding the need for complex waveform analysis. By taking out only the critical parameter (ToF) rather than analyzing complete waveforms, the system achieves sufficient discrimination accuracy with simpler hardware that only needs to measure time intervals between detector events.
Solution Approach 2:
The invention replaces complex electronic waveform analysis systems with a simpler time-interval measurement system. Instead of using sophisticated signal processing hardware to analyze pulse waveforms, the system substitutes a time-to-digital converter that merely measures the time between detection events, significantly reducing hardware complexity while maintaining discrimination capability.
3Measurement precision
If high sampling rate acquisition is used to capture PD pulses, then pulse detection capability is improved, but data acquisition complexity and processing requirements increase
Solution Approach 1:
The system performs preliminary detection at two spatially separated detectors before any complex analysis. By pre-measuring the time interval of flight at the detection stage itself, the system captures the essential PD characteristic without requiring high sampling rate acquisition. The preliminary time measurement is sufficient for discrimination, eliminating the need for high-speed data acquisition systems.
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 reliable discrimination of partial discharge pulses from noise in both AC and DC systems, reducing the need for complex hardware and enabling efficient monitoring of electrical components, particularly in DC systems where phase-resolved methods are not applicable.
Implementation Method 1
a first detector configured to detect an electromagnetic impulsive signal from a first area of an electrical object and generate a first electrical pulse; a second detector configured to detect the electromagnetic impulsive signal from a second area of the electrical object and generate a second electrical pulse
Data Source
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AI summary
It is described a processing apparatus (2) for detecting partial discharge pulses in the presence of noise signal, comprising: a first detector (3) configured to detect an electromagnetic impulsive signal (PINT; PEX2) from a first area (9) of an electrical object (1, 6) and generate a first electrical pulse (P1) representing a first detection event of the electromagnetic impulsive signal; a second detector (4) configured to detect the electromagnetic impulsive signal from a second area (10) of the electrical object (1, 6) and generate a second electrical pulse (P2) associated with a second detection event of the electromagnetic impulsive signal; a time calculation module (17) configured to measure a time interval (Td1;Td2) between the first detection event and the second detection event; and a processing module (18) connected to the time calculation module (17). The processing module (18) is configured to: compare the measured time interval (Td1;Td2) with a time threshold value (THt); associate the electromagnetic impulsive signal (PINT) to partial discharge pulses generated inside the electrical object (1, 6) between the first and second areas (9, 10) if the measured time interval (Td1) is lower than the time threshold value (THt); and associate the electromagnetic impulsive signal (PEX2) to a noise signal generated outside the electrical object (1, 6) if the measured time interval (Td2) is equal to or greater than said time threshold value (THt).