PWM active filter for DC power systems
US6424207B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 18, 2001 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Apr 18, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/15
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An active filter circuit for filtering unwanted AC voltages and currents from a DC power system, and including a power circuit and a control circuit. The power circuit consists of two semiconductor power transistors, respective anti-parallel diodes, an inductor and at least one capacitor. The control circuit generates pulse width modulated (PWM) control signals for operating the transistors such that when one transistor is conducting, the other transistor is non-conducting, and vice versa. The filter implements an auxiliary DC voltage bus by charging the capacitor which acts as a reservoir of energy. The DC level of this auxiliary bus is controlled by controlling the DC component of the duty cycle. The AC component of the duty cycle is used to modulate the current drawn from or supplied to the DC power system so as to cancel unwanted AC voltages and currents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.