In this work, a novel methodology based on Hilbert Transform (HT) for phasor estimation (magnitude and phase angle), frequency, and ROCOF
When the first part of the disturbance in a cycle starts, it is checked whether the absolute value of the ROCOF
is equal to 1.5/[T.sub.1] or not.
Since the null hypothesis of constant failure rate cannot be rejected, it makes most sense to use the constant failure rate model to predict the ROCOF
. This was done and the MTBF was determined to be 124 days, with a 95% confidence interval of 73 days to 209 days.
In order to assess the validity of the IID assumption, rate of occurrence of failures (ROCOF
) curves have to be drawn and Laplace tests for trend estimated.
* Rate of occurrence of failures (ROCOF
): appropriate in a system which actively controls some potentially dangerous process.