Fault tolerant signal validation for feedwater control system
US5386441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1991 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Jun 24, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In a nuclear reactor the feedwater control system receives steam generator water level signals, including information to determine signal quality. The signal quality and additional signal validation determine how the water level signals are to be used by the feed-water control system. In the preferred embodiment, each water level signal is compared with a possible range and the difference or differential between all possible pairs of the signals is calculated and compared with an acceptable differential range. While alarms are sounded if any of these checks on the water level signals indicate an invalid signal, the water level signals are used to calculate a median level signal until there is less than two water level signals with good quality within the possible range or all differentials are outside the acceptable differential range. Thus, a single bad signal does not affect median signal selection, but the feedwater control system automatically switches to manual when a second invalid signal is detected, thereby preventing an inappropriate control action.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.