Dynamic motor current phase unbalance protection
US10424913B2 · kind B2 · utility
0Cited by
7References
7Claims
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Key dates
| Filing date | Dec 20, 2017 |
| Grant date | Sep 24, 2019 |
| Priority date | — |
| Expiry date | Dec 20, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/09
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In accordance with an example embodiment of the invention, in an overload relay for a three-phase motor, an adjusted threshold for detected current phase unbalance is dynamically determined at which the relay will be tripped. The adjusted threshold is a function of a ratio of an average of currents in the three-phases to the rated full load current of the motor, i.e., motor load. As the motor load decreases, the adjusted current phase unbalance threshold is increased, causing the resulting trip time to increase, thereby increasing motor run time and reducing downtime.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.