Motor controller for pumping units
US4935685A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1987 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Aug 12, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/0822
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for controlling the operation of an oil well pumping unit in which the prime mover is a polyphase AC electric motor. The system comprises means for generating a plurality of signals representative of motor fault parameters including a motor winding overtemperature fault, undervoltage fault, and a phase imbalance fault. Upon occurence of a fault, a contactor in the motor supply leads is open to shut down the motor. After such shutdown because of undervoltage or phase imbalance faults the fault parameters are continuously scanned and once the fault has been cleared the motor is restarted. Where motor shutdown occurs because of an over temperature fault, the motor is maintained in a latched off shut down condition until an operator implemented reset occurs. An accessible counting memory is provided having separate registers for each of the fault conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.