If the value of Vw3 is very small, then the frequency deviations
estimated from equation (10) will not be accurate. Ako, it the value
of Vsin@ is very small, the frequency deviations estimated from
equation (11) will not bc accurate. However, by using equation (12)
for the calculation of the frequency deviation, one can know which
of the equations (10) or (11) to use.
The rate of change of the frequency at instant k can be estimated
using the following equations