Motor Speed Oscillation Monitoring for Failed Channel Identification
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Solution Overview
Problem
In power drive units (PDU) with multiple channels, determining which channel has failed is challenging due to mechanical coupling, causing normally functioning channels to exhibit similar output patterns to failed channels, making it difficult to differentiate between symmetric and asymmetric oscillations.
Innovation Solution
A motor assembly with a processor that detects symmetric and asymmetric oscillations in the speed signal by using threshold comparisons and counters to differentiate between 'true' and 'false' readings, allowing identification of failed channels for appropriate shutdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple channels are used in power drive units to maintain operation during failure, then system reliability is improved, but it becomes difficult to identify which channel has failed due to mechanical coupling effects
Solution Approach 1:
The patent applies asymmetry by analyzing the asymmetric oscillation patterns in speed signals to identify failed channels. When one channel fails, the mechanical coupling causes asymmetric oscillations in the remaining functional channels, which can be detected and used to identify the failed channel. This transforms the harmful coupling effect into a useful diagnostic signal.
Solution Approach 2:
The patent implements feedback by continuously monitoring speed signals from sensors and analyzing oscillation patterns to identify channel failures. The system provides real-time feedback on channel status, enabling dynamic identification of failed channels while maintaining system operation through the remaining functional channels.
2Force
If mechanical coupling between channels is used to maintain torque output during channel failure, then power transmission capability is improved, but normally functioning channels exhibit similar output patterns to failed channels making differentiation difficult
Solution Approach 1:
The patent exploits the asymmetric oscillation patterns that arise due to mechanical coupling between channels. By analyzing the asymmetry in speed signals, the system can precisely differentiate between failed and functioning channels while maintaining torque output through the coupling mechanism.
Solution Approach 2:
The patent changes the measurement parameter from simple speed monitoring to analyzing oscillation characteristics (amplitude, frequency, asymmetry) of speed signals. This parameter transformation enables precise differentiation of channel states while maintaining the mechanical coupling for torque transmission.
3Measurement precision
If symmetric oscillation detection is used to identify failed channels, then channel identification accuracy is improved, but false readings may occur due to asymmetric oscillations in normally functioning channels
Solution Approach 1:
The patent resolves this contradiction by analyzing asymmetric oscillation patterns rather than relying solely on symmetric patterns. By detecting the specific asymmetry characteristics that arise from mechanical coupling, the system achieves accurate channel identification without false readings from normally functioning channels.
Solution Approach 2:
The patent uses continuous feedback from speed sensors to monitor oscillation patterns in real-time. This enables dynamic adjustment of detection criteria based on actual system conditions, reducing false readings while maintaining high identification accuracy for failed channels.
Data Source
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AI summary
A monitoring system is disclosed for identifying an operating state of a motor, the system comprising: a speed sensor for determining a speed of a motor and providing a speed signal as a function of time in response thereto, and a processor configured to identify a symmetric and/or an asymmetric oscillation of the speed signal as a function of time.