Pump-off control method of pump jack
US6599095B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2001 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Oct 29, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B2203/0204
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A pump off control method comprises detecting the speed of the induction motor and an instantaneous value of secondary current of the induction motor. Down stroke time in every cycle of the pump jack is detected. An average value of instantaneous values of the secondary current of the induction motor in the down stroke time in said every cycle is calculated. An average value reference of the secondary current of the induction motor to be compared with calculated average value of the instantaneous values of the secondary current of the induction motor is set. The calculated average value of the instantaneous values of the secondary current is compared with the average value reference after the down stroke end in each cycle. An occurence of pump off is detected if the calculated average value of the instantaneous values is greater than the average value reference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.