Stator Lamination Fault Detection During Electric Machine Operation
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Solution Overview
Problem
Existing methods for detecting insulation failures in generator stators require offline inspections during maintenance, leading to unplanned outages and increased costs due to the inability to identify damage in real-time.
Innovation Solution
A sensor system comprising sensor coils and detectors that measure and compare signals to detect short circuits between stator laminations, allowing for real-time identification of insulation failures using passive or active methods, including coil arrangements and excitation signals to pinpoint the location and extent of damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If offline inspections during maintenance are performed, then damage can be detected, but unplanned outages and increased costs occur due to inability to identify damage in real-time
Solution Approach 1:
The patent applies preliminary action by continuously monitoring insulation conditions during normal operation through sensor coils that detect eddy current losses, enabling damage identification before it progresses to failure and requiring planned outages for inspection
Solution Approach 2:
The system implements feedback by continuously measuring signal characteristics from sensor coils and comparing them against baseline values to detect changes in insulation condition, providing real-time information about insulation degradation without interrupting generator operation
2Measurement precision
If inspections are performed during planned outages, then damaged components can be identified, but repair costs and downtime increase
Solution Approach 1:
The patent ensures continuity of useful action by maintaining continuous monitoring of insulation conditions during generator operation, eliminating the need to stop production for inspections and enabling timely detection of insulation degradation without sacrificing measurement accuracy
3Reliability
If real-time monitoring is implemented, then insulation failures can be detected during operation, but device complexity increases
Solution Approach 1:
The system applies self-service by utilizing the generator's own operating parameters and magnetic field to induce eddy currents in the stator core, which are then measured by sensor coils to detect insulation conditions, eliminating the need for external complex testing equipment during operation
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
Enables real-time detection of insulation failures, reducing unplanned outages and maintenance costs by identifying potential short circuits and damage during operation, thereby improving generator efficiency and reliability.
Implementation Method 1
If the insulation between the laminations is damaged the alternating magnetic flux through the stator core can generate eddy currents flowing between the laminations. Using a Chattock potentiometer coil to measure magnetic potential difference
Implementation Method 2
the alternating magnetic flux through the stator core can generate eddy currents flowing between the laminations
Implementation Method 3
A sensor coil surrounds a portion of the plurality of laminations and conducts a first signal. A detector is electrically connected to the sensor coil to measure the first signal
Data Source
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AI summary
An electric machine includes laminations stacked along a longitudinal axis to define a stator core. The laminations cooperate to define a plurality of slots that extend in a direction parallel to the longitudinal axis, and include a first lamination, a second lamination, and an insulation layer between the first lamination and the second lamination. A plurality of windings is disposed in the plurality of slots, the plurality of windings operable to conduct a current at a desired voltage and a desired frequency. A sensor coil surrounds a portion of the laminations and conducts a first signal. A detector is electrically connected to the sensor coil to measure the first signal and to compare the first signal to a second signal, a difference between the first signal and the second signal being indicative of a short circuit between the first lamination and the second lamination.