Self-optimizing voltage control of an induction motor
US4408149A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Sep 8, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P23/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An adaptive control system for improving the efficiency of an electric motor. Connected in series with the motor and across the voltage supply is an electronic bi-directional switch which may be triggered at differing times relative to the zero-crossing of the AC supply to thereby control the amount of time during each cycle that the motor is energized. The firing angle for the electronic switch is determined by an optimizing network which functions to introduce a relatively low frequency perturbation in the firing angle and means for sensing the effect of that change on the average power being drawn by the system during the period of the perturbation. If this small, periodic change in the firing angle of the electronic switch results in a decrease in average power consumption, the firing angle is adjusted in a direction which is determined to have precipitated the improvement. Alternatively, if the shift in firing angle occasioned by the minute perturbation resulted in a worsening of motor performance, i.e., higher power consumption, the system functions to adjust the firing angle in an opposite direction so that, again, overall performance is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.