Motor Drive Input Filter Testing for Degradation Detection

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Solution Overview

Problem

Existing motor drive electronics in aircraft lack built-in or online health monitoring capabilities to detect component degradation in input filter networks, leading to potential erroneous motor control and costly unscheduled maintenance.

Innovation Solution

A method involving isolating the motor drive circuit, injecting a test signal through the input filter network, measuring the propagated signal, and comparing it to a reference signal to identify component degradation, allowing for proactive monitoring and preventive maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no health monitoring capability is provided in motor drive electronics, then the system structure remains simple and cost-effective, but component degradation cannot be detected leading to unscheduled maintenance and system failures

Engineering Contradiction:
Improvedetection of component degradationVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The motor drive circuit performs self-diagnosis by using its own controller to generate test signals, measure propagated signals through the input filter network, and compare results against reference signals stored in memory. This self-monitoring capability eliminates the need for external monitoring equipment while enabling degradation detection of input filter components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Reference signals are pre-stored in the controller's memory during system initialization or manufacturing. These reference signals represent the expected propagated signal characteristics when the input filter is healthy. During operation, measured signals are compared against these pre-stored references to detect any deviations indicating component degradation.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the motor drive circuit operates continuously without isolation, then productivity is maintained, but accurate testing of input filter components cannot be performed

Engineering Contradiction:
Improvetesting accuracyVSAvoidsystem availability
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The health monitoring is performed periodically during scheduled maintenance intervals or at predefined checkpoints rather than continuously. The controller isolates the motor drive circuit, performs the test signal injection and measurement sequence, then restores normal operation. This periodic testing approach ensures accurate component assessment while minimizing disruption to system productivity.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The testing process is segmented into distinct phases: isolation of the motor drive circuit from the power source, injection of test signals through the input filter network, measurement of propagated signals, comparison with reference signals, and restoration of normal operation. This segmentation allows accurate testing to be performed in controlled intervals without compromising overall system availability.

Inventive Principle:
Principle #1Segmentation

3Reliability

If traditional monitoring methods are used, then the system structure remains simple, but degradation detection is impossible leading to erroneous motor control

Engineering Contradiction:
Improvemotor control reliabilityVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller leverages existing system resources including its own processing capabilities, memory for storing reference signals, and output interfaces for signal injection. By repurposing these existing components for diagnostic functions, the system achieves reliable degradation detection without adding separate monitoring hardware, thus maintaining cost-effectiveness while improving motor control reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller serves multiple functions: it manages normal motor drive operations, stores reference signals for degradation detection, generates test signals for input filter testing, measures propagated signals, and performs comparative analysis. This multi-functionality consolidates monitoring capabilities within the existing controller, avoiding additional hardware complexity while ensuring reliable degradation detection for accurate motor control.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4450989A1Health monitoring of input filter for degradation detection
Publication Date: 2024.10.23 HAMILTON SUNDSTRAND CORP
  • EP4450989A1 patent drawingFigure 1
  • EP4450989A1 patent drawingFigure 2
  • EP4450989A1 patent drawing

AI summary

There is provided a method for monitoring degradation of at least one component in a power system comprising a motor drive circuit configured to provide AC power from a power source (1) to power a motor (7). The method comprises isolating the motor drive circuit from the power source (1); injecting a test signal to at least one component of the isolated motor drive circuit; and measuring a propagated signal resulting from the injected test signal propagating through the at least one component. The propagated signal may be compared to a test signal and, if the propagated signal differs from the test signal by a threshold, then degradation of the at least one component may be identified.