Frequency spectrum variation monitoring system
AssigneeHitachi, Ltd.
InventorsKanji Kato, Satoshi Tanisaka
Life of this patent
Estimating the term…
Abstract
In a frequency spectrum variation monitoring system, the values of two parameters including the root mean square (RMS) value of each of the output signals from various detectors disposed at several locations in a nuclear power plant and the RMS value of the time-differentiated version of the detector output signal are calculated both at the normal state and at any time instant. These parameter values are used to obtain the RMS value of the deviation of the frequency spectrum of the detector output signal from the normal state and the average frequency weighted with that frequency spectrum deviation, so that the geometrical variation in frequency spectrum of the detector output signal may be monitored.
Claims7
A frequency spectrum variation monitoring system comprising:
- first means for producing a first analog signal in a specific frequency range in response to receipt of a plant input signal having a given frequency range;
- second means for receivng said first analog signal to deliver a second analog signal which is the time-differentiated version of said first analog signal;
- third means for converting said first and second analog signals into first and second digital signals respectively;
- fourth means for calculating the root mean square value and average frequency of said first analog signal on the basis of said first and second digital signals;
- fifth means for storing the calculated results of said fourth means;
- sixth means for calculating the differences between each of the root mean square value and average frequency previously stored in said fifth means and each of the instantaneous root means square value and average frequency calculated by said fourth means so as to calculate the root mean square value and average frequency of an anomalous peak component in said plant input signal on the basis of the output signals produced by said fourth and fifth means when said differences exceed predetermined values;
- and
- seventh means for indicating the calculated results of siad sixth means.
Dependencies are inferred from the claim text.