Synchronous Motor Fault Detection via Stator-Rotor Position Estimation
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Solution Overview
Problem
Existing methods for detecting faults in synchronous motors, such as bearing faults and eccentricity faults, face challenges due to variations in load, speed, and power ratings, as well as interference from background noise, making it difficult to accurately identify fault thresholds and types.
Innovation Solution
The proposed solution involves using principles of magnetostatics to represent the structure of the synchronous motor through weighted summations over real-space basis functions, allowing for online estimation of the mutual position between the stator and rotor, and subsequently detecting different types of faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration or acoustic analysis is used for bearing fault detection, then fault detection capability is provided, but accuracy is influenced by background noise and sensitivity changes based on sensor mounting positions
Solution Approach 1:
The patent replaces mechanical vibration/acoustic sensing with electrical signal analysis. Instead of using physical sensors mounted on the motor housing to detect mechanical vibrations, the system analyzes electrical signals (currents and voltages) from the motor's electrical components. This substitution eliminates the problems of mechanical sensor mounting variability and background noise interference, as electrical signals provide a more stable and noise-resistant measurement medium for detecting bearing faults and eccentricity conditions.
2Reliability
If stator current analysis is used for bearing fault detection, then alternative detection approach is provided, but magnitude of stator current varies at different loads, speeds, and power ratings making threshold identification difficult
Solution Approach 1:
The patent transforms the detection approach by changing from analyzing absolute current magnitudes to analyzing electrical impedance characteristics and signal frequency spectra. Instead of setting fixed current thresholds that vary with load and speed, the system measures impedance (ratio of voltage to current) and analyzes frequency components of electrical signals. These electrical parameters provide fault indicators that are consistent across different operating conditions, eliminating the adaptability problem of current-based threshold detection.
3Adaptability or versatility
If different techniques are tuned to detect different types of faults, then various fault types can be detected, but system complexity increases and unified detection method is lacking
Solution Approach 1:
The patent implements a universal electrical signal analysis system that can detect multiple fault types (bearing faults, static eccentricity, dynamic eccentricity, and mixed eccentricity) through a single unified approach. By measuring electrical currents and voltages and analyzing their frequency spectra and impedance characteristics, the system provides multi-functional fault detection without requiring separate mechanical sensors or multiple specialized techniques, thereby reducing overall system complexity while maintaining comprehensive fault coverage.
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 provides a compact and memory-efficient representation of the magnetostatic, enabling effective online fault detection and reducing computational costs, thereby improving the accuracy and reliability of fault identification in synchronous motors.
Implementation Method 1
determine different magnetostatics for different mutual positions at different instances of time by calculating, for each mutual position, a weighted summation over real-space basis functions
Data Source
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AI summary
The present disclosure provides a system and a method for detecting a fault of an operation of a synchronous motor. The method includes collecting an electrical input and measurements associated with the operation of the synchronous motor caused by the electrical input. The method further includes determining sequences of points defining a mutual position between a stator and a rotor of the synchronous motor that results in magnetostatic determined as a weighted summation over real-space basis functions parameterized on pairs of adjoint points in the determined sequence of points and weighted with a surface charge density between corresponding adjoint points, such that the resulted magnetostatic explains the measurements of the operation of the synchronous motor given the electrical input. Further, the method includes determining the fault of the operation of the synchronous motor based on the mutual position between the stator and the rotor of the synchronous motor.