Load-based control of an AC motor
US4987351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1990 |
| Grant date | Jan 22, 1991 |
| Priority date | — |
| Expiry date | Jan 11, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P23/0077
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An AC motor control based on an iterative computation of the motor load and method of accurately determining motor load. At the initiation of motor operation, the load term (%LOAD) is initialized to zero, and the motor is energized in accordance with a predetermined voltage and frequency schedule for producing motor rotation. During the starting interval the power loss term LOSSES and the load term (%LOAD) are iteratively computed as a function of the input voltage and current (V.sub.bus, I.sub.bus) and the motor inverter frequency (IF). When a predetermined motor speed has been achieved, the run mode is initiated. At this point, the load is known based on the iterative load calculations performed during starting, and the motor voltage and inverter frequency are scheduled as a function of motor speed and load. The iterative computation of losses and load continue during the run mode so that changes in the motor load are taken into account.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.