Vibration Signal Modulation for Rotary Machine Protection
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Solution Overview
Problem
Rotary machines, such as wind turbines, often experience excessive vibrations due to imbalances during installation and operation, leading to potential damage and costly repairs, with existing monitoring systems being complex and sensitive to noise, making them ineffective in high noise environments.
Innovation Solution
A system and method that measures low-amplitude vibration signals using sensors, modulates them at a desired frequency to convert to a direct current value, filters the signal using simple low-pass filters, and compares the amplitude to a threshold to detect imbalances, implementing corrective actions like shutdown to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional monitoring systems using phase lock loop are used to detect vibrations, then the system can track phase relationships, but the system becomes complex and sensitive to noise leading to incorrect detection
Solution Approach 1:
The patent extracts only the essential feature needed for vibration detection - the amplitude information at specific frequencies - while discarding the complex phase tracking mechanism. By using a frequency discriminator that directly measures amplitude at predetermined frequencies, the system achieves accurate vibration detection without the complexity of phase lock loops.
Solution Approach 2:
The patent creates a simplified model of vibration detection by using a frequency discriminator that copies the essential amplitude information at specific frequencies. Instead of implementing the full complex phase lock loop system, it creates a simplified copy that captures only the necessary vibration characteristics for protection purposes.
2Reliability
If conventional monitoring systems are used to detect vibrations, then vibration tracking is possible, but the system is sensitive to noise in the vibration signal leading to skewed results
Solution Approach 1:
The patent converts the harmful noise effect into a benefit by using band-pass filters tuned to specific frequency ranges. The noise is filtered out at frequencies other than the predetermined vibration frequencies, and the system actually benefits from this selective filtering by focusing only on the relevant frequency bands where mechanical vibrations occur.
Solution Approach 2:
The patent applies local quality by using multiple band-pass filters, each tuned to detect vibrations at specific frequency ranges corresponding to different mechanical components. Instead of trying to process the entire vibration signal spectrum, the system applies localized filtering at specific frequency bands, making it highly reliable for detecting vibrations from specific machine parts while ignoring noise elsewhere.
3Ease of operation
If complex control technologies are used for vibration monitoring, then phase matching can be achieved, but the system requires complex calculations and is sensitive to noise
Solution Approach 1:
The patent replaces the mechanical phase lock loop system with an electronic frequency discriminator system. Instead of using complex phase calculations and feedback control, the system uses direct amplitude measurement at predetermined frequencies through band-pass filters and rectifiers, dramatically simplifying the operation and eliminating complex calculations.
4Reliability
If vibration detection systems are implemented, then damage prevention is possible, but the system must operate effectively in high noise environments
Solution Approach 1:
The patent applies local quality by using multiple band-pass filters, each tuned to detect vibrations at specific frequency ranges corresponding to different mechanical components. Instead of trying to process the entire vibration signal spectrum, the system applies localized filtering at specific frequency bands, making it highly reliable for detecting vibrations from specific machine parts while ignoring noise elsewhere.
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
Effectively detects and mitigates vibrations in high noise environments, preventing damage by reliably identifying low-frequency amplitudes and allowing for proactive maintenance, reducing downtime and expenses.
Implementation Method 1
at least one sensor measures a vibration signal within the rotor
Implementation Method 2
the vibration signal is modulated at a desired frequency to generate a modulated signal
Implementation Method 3
the modulated signal can then be easily filtered via a low pass filter
Data Source
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AI summary
The present disclosure is directed to a system and method (100) for protecting a rotary machine in a high noise environment. In one embodiment, the method (100) includes a step (102) of measuring a vibration signal (75) during operation of the rotary machine. Another step (104) includes modulating the vibration signal (75) at a desired frequency to generate a modulated signal having a direct current (DC) value. The desired frequency varies as a function of an operational parameter of the rotary machine. The method (100) also includes a step (106) of filtering the modulated signal via one or more low-pass filters (90, 92). Another step (108) includes comparing an amplitude (96) of the filtered signal to a threshold amplitude for one or more components of the rotary machine. The threshold amplitude is indicative of an imbalance within one or more components of the rotary machine. The rotary machine is then operated (110) based on the comparison so as to protect the rotary machine from damage caused by the imbalance within the one or more components of the rotary machine.