Method and apparatus for pulse width modulation of a power supply for increased transient stability in subsurface wellbore pumps
US6043995A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 9, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Sep 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M5/4585
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable speed controller is provided which utilizes a combination of pulse width modulation and fixed pulse control, such as a conventional six-step control, in order to generate multiphase sinusoidal power signals for use by downhole wellbore equipment, such as electrical submersible pumps. A controller is utilized to monitor at least one DC voltage level of the rectifier and/or inverter circuit of a variable speed controller. The DC level is compared to an optimum DC level. A triggering threshold is established. Once the triggering threshold is surpassed, the controller is utilized to switch between a conventional six-step mode of control and a pulse width modulation mode of control in order to better respond to a positive transient voltage condition. The pulse width modulation mode of operation provides for real time counteracting of the positive transient condition. Once the controller determines that the transient condition has subsided, control is returned to the conventional six-step control mode of operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.