GE Industrial Solutions 6KCV300WPD - Manual (Page 198)

GEL100340
Time-Derivative
Description
It performs a discrete time derivative of the input
User can filter the time derivative with first order low pass filter with a filter time constant
It is also possible to Reset the output.
It is the discretization of the continuous time derivative in series to a first order low pass filter and it is
described by the following
transfer function:
1
z ’ s
where is the time constant of the filter.
The relation between and the cut-off frequency is:
The relation between these two values is:
fa?
while the relation with the cut-off frequency [Hz] is:
Value of is usually between 0.03 and 0.3
The following diagram is used to perform the transfer function F(s)
1 8 8