Protection system for immunizing a controlled d-c power supply against a-c line voltage interruptions
US4620296A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1984 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | Nov 29, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/493
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
When a d-c bus voltage is produced by rectifying applied a-c power line voltage in a rectifier bridge (such as a phase-controlled SCR rectifier bridge), controlled by a feedback loop which compares a feedback signal representing the d-c bus voltage with a command signal representing a desired set point level and from the comparison automatically maintains the bus voltage at the set point level, unwanted a-c line voltage interruptions may have a deleterious effect on the rectifier bridge itself and on a load driven by the bus voltage. This occurs because during a power interruption (when the bus voltage drops) the command signal causes the feedback loop to impose a control on the rectifier bridge which attempts to increase the d-c bus voltage back to the magnitude represented by the command signal. When power is subsequently restored, the d-c bus voltage will suddenly increase very sharply and may destroy electrical and/or mechanical components in the system. Immunization against the effects of the power interruptions is obtained by substituting the feedback signal for the command signal, during the occurrence of a power interruption, which will shut the rectifier bridge down and wi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.