Control circuits for inverters
Abstract
Abstract In the transmission of direct current from a rectifier to an inverter one method of control has been to provide a constant current at the rectifier and a constant extinction angle at the inverter controlled by a fixed extinction angle order signal. Instability results with this form of control under certain operating conditions. In the present invention the tendency to instability is reduced by controlling the extinction angle of the inverter in accordance with the fixed order signal when the inverter output current is at least equal to a required level, but increasing the extinction angle when the inverter current is less than the required level. The extinction angle is increased under the control of an auxiliary order signal generated by a summing unit which sums a signal from a control circuit representing the actual extinction angle, the fixed order signal, and a signal from an amplifier dependent on the difference between the actual and required current levels.
Inventors
- 👤 John Desmond Ainsworth
Bibliographic Details
Claims Analysis
Total Claims: 7References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |