Power frequency converter
US4293904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1979 |
| Grant date | Oct 6, 1981 |
| Priority date | — |
| Expiry date | Nov 21, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power converter which provides precise waveshape regulation. An input pr waveform (three-phase or single phase power) is rectified and modulated to form a chopped waveform within an envelope defined by the rectified input waveform. The modulation is removed by passing the chopped signal through a low-pass filter. The output of the low-pass filter, which is equal to the instantaneous value of the chopped waveform envelope times the instantaneous value of the duty cycle of the chopped waveform, is converted to a complete sine wave output voltage in a power inverter. The output of the power inverter is sampled and compared with a low-power reference waveform in a differential amplifier. The output of the differential amplifier is phase compensated for the effects of the low-pass filter and applied as an error signal to a pulse-width-modulated oscillator to adjust the duty cycle of the chopped waveform so that the sine wave output voltage follows the reference waveform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.