Motor Control Device Power Line Breakage Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control devices face challenges in accurately detecting power line breakages during motor operation due to delays in current control loops and noise interference, leading to potential erroneous detection, especially when voltage command values saturate or current deviations are large.
Innovation Solution
A motor control device that calculates current deviations and applies filtering to index data derived from current deviations, absolute values, and power of deviations to accurately detect power line breakages, while suspending detection during voltage command saturation and high motor speeds to prevent false positives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If current deviation is monitored as it is to detect power line breakage, then detection responsiveness is improved, but measurement precision deteriorates due to control loop delays and noise causing erroneous detection
Solution Approach 1:
The patent applies preliminary action by calculating the moving average of current deviation before using it for breakage detection. This preprocessing step prepares the data in advance to eliminate the effects of control loop delays and noise, ensuring that when the detection is performed, the data is already refined and reliable, thus maintaining responsiveness while improving accuracy.
Solution Approach 2:
The patent introduces a moving average calculation as an intermediary processing step between current deviation measurement and breakage detection. This intermediary component filters out noise and delay effects while preserving the essential breakage information, acting as a mediator that reconciles the conflict between fast detection and accurate measurement.
2Reliability
If voltage command value saturation is not considered in breakage detection, then detection coverage is improved, but reliability deteriorates due to false positive detections during saturation conditions
Solution Approach 1:
The patent applies local quality by differentiating the detection criteria based on the operating condition. When voltage command saturation is detected, the system switches to a different detection logic that accounts for saturation effects. This localized adaptation ensures high reliability in saturation conditions while maintaining detection coverage in normal conditions through conditional judgment.
3Productivity
If detection is performed during motor operation, then productivity is improved, but measurement precision deteriorates due to noise accumulation and control delays
Solution Approach 1:
The patent implements continuity of useful action by enabling ongoing breakage detection during motor operation without interruption. The moving average calculation continuously processes current deviation data, allowing the system to maintain detection functionality throughout operation, thereby preserving productivity while the filtering mechanism ensures measurement precision is maintained despite continuous noise exposure.
Data Source
AI summary
A motor control device includes a current command calculation unit configured to calculate a current command value for driving a motor, a current detection unit configured to detect a value of a current that flows through a power line of the motor, a current deviation calculation unit configured to calculate a current deviation, which is a difference between the current command value and the detected current value, a voltage command calculation unit configured to calculate a voltage command value applied to the motor based on the current deviation, a filter processing unit configured to calculate data by filtering the current deviation, the absolute value of the current deviation, or the power of the current deviation and to output the data as index data, and a power line breakage detection unit configured to detect a breakage of the power line based on the index data.