Rotor resistance based motor thermal protection
US11128253B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 20, 2020 |
| Grant date | Sep 21, 2021 |
| Priority date | — |
| Expiry date | Mar 26, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2207/01
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Motor overload protection device is equipped with a thermal monitor that can determine expected rotor temperature rise from rotor resistance estimates. The thermal monitor determines expected rotor temperature rise by using a correlation between rotor temperature rise computed from rotor resistance estimates, and motor thermal state estimates. The correlation can be derived by fitting a line to a plurality of points, with each point defined by an ordered pair composed of a rotor temperature rise estimate and a corresponding motor thermal state estimate, and determining a slope of the line. This rotor temperature slope can then be used by the thermal monitor to determine a rotor temperature rise given a rotor resistance estimate and a corresponding motor thermal state estimate. If the rotor temperature rise exceeds an expected rotor temperature rise by more than a predefined threshold, the thermal monitor issues an alarm and/or takes corrective actions in some embodiments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.