Power factor control for switched mode rectifiers with improved representing of currents in EMI capacitive elements
US5777866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1997 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Jan 27, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power factor correction system with an EMI line filter at the input includes circuitry to sense the capacitor current of the EMI filter to improve the accuracy of the power factor enhancement. The circuitry consists of a current sensing means connected after the EMI filter, and a voltage sensing capacitor which derives its input signal from a pair of diodes separate from the conventional 4-diode rectifier bridge, which are connected either before or after the EMI filter. The current-sensing means, which may be a resistor, and the voltage-sensing capacitor are tightly coupled to the current control loop of the power factor correction system to compensate for the current in the EMI filter capacitors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.