Sensorless Reverse Rotation Detection in De-Energized Electric Machines
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Solution Overview
Problem
Existing methods for determining the rotation direction of a de-energized electric machine without physical access are inefficient, as they require sensors on the machine, which are costly and difficult to install, especially for remote and harsh environments.
Innovation Solution
A computer system that analyzes waveforms of electrical power indicia, such as voltages and currents, measured remotely from the machine to distinguish between energized and de-energized states, and detects reverse rotation by comparing phase sequences, allowing for sensorless detection and estimation of rotation duration and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensors are installed on the machine to detect rotation direction, then measurement precision is improved, but device complexity and installation difficulty increase
Solution Approach 1:
The patent uses power indicia waveforms as an intermediary to indirectly detect machine rotation direction. Instead of directly measuring mechanical rotation with sensors, the system analyzes electrical waveform characteristics (phase sequences) during de-energized states, which are influenced by rotation but can be measured remotely without physical contact with rotating parts.
Solution Approach 2:
The patent replaces mechanical sensing systems with electrical field-based detection. By substituting physical sensors that contact the machine with remote electrical waveform analysis, the system eliminates mechanical installation complexity while maintaining detection capability through analysis of power indicia during de-energized states.
2Reliability
If sensors are installed on the machine, then reverse rotation detection capability is improved, but installation cost and difficulty increase
Solution Approach 1:
The system uses the machine's own electrical infrastructure (power conductors and existing waveforms) to perform self-diagnosis of rotation direction. The power indicia already present in the system during de-energized states contain information about rotation, eliminating the need for separate sensing systems and reducing installation requirements to just waveform measurement points.
Solution Approach 2:
The waveform measurement system serves multiple functions: it monitors machine operation during energized states and detects rotation direction during de-energized states. This multi-functionality eliminates the need for dedicated reverse rotation sensors, reducing overall system complexity and installation requirements while maintaining reliable detection capability.
3Measurement precision
If physical access to the machine is required for sensor installation, then measurement accuracy is improved, but ease of operation deteriorates
Solution Approach 1:
The patent uses power indicia waveforms as a remote intermediary that carries information about machine rotation without requiring physical proximity to the rotating parts. These electrical signals can be measured at a distance from the machine through accessible conductors, enabling accurate rotation direction detection while maintaining operator safety and ease of remote access.
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
Enables remote, cost-effective monitoring of electric machines without the need for sensors on the machines, providing advanced notice of potential issues and reducing maintenance costs by accurately detecting reverse rotation and estimating rotation speed.
Implementation Method 1
the second time segment is for times when the at least one waveform arises from power induced on supply conductors for the machine by rotation of the machine
Data Source
AI summary
For determining rotation of a de-energized electric machine without accessing the machine, wherein the machine in the energized state rotates in a reference direction, a computer system determines, for at least one waveform of at least one set of multi-phase electrical power indicia measured remotely from the machine, that a first time segment of the at least one waveform corresponds to an energized state of the machine and that a second time segment of the at least one waveform corresponds to a de-energized state of the machine. The computer system also determines that the machine in the de-energized state has rotated in a direction reverse to the reference direction, wherein the determining that the machine in the de-energized state has rotated in a direction reverse to the reference direction includes comparing the first and second time segments of the at least one waveform.