Determining phase of AC mains in PWM controlled converters without voltage sensors
US6459599B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 2001 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Jun 1, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/219
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a pulse width modulation-controlled, switched bridge, DC converter, the phase angle (44, 45) of the AC mains (4) is provided without sensing the voltage thereof, by a phase-locked loop (47) having one input (75) derived (126) from the in-phase voltage command Vde* (61) and another finit (77) approximating the line frequency; the phase-locked loop is initialized at a phase angle &thgr;init(76) equal to the arctangent (124) of the in-phase Vdest, and quadrature Vqest representation of estimated line voltages ere, ese, ete (119-121) derived during an initialization cycle from reconstruction of the fundamental component of the AC main currents at a phase angle (93) changing with said frequency. Reconstruction includes providing the discrete Fourier transform (DFT, 81) of signals indicative of currents (37) in the AC mains and the inverse DFT (122) of the resultant Fourier coefficients eia, eib.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.