ABB ret650, Technical Manual

Page: 484 / 670

The Trip value recorder calculates the values of all selected analog input signals
connected to the Disturbance recorder function. The result is magnitude and phase
angle before and during the fault for each analog input signal.
The trip value recorder information is available for the disturbances locally in the IED.
The trip value recorder information is an integrated part of the disturbance record
(Comtrade file).
14.8.2 Function block
The Trip value recorder has no function block of it’s own.
14.8.3 Signals
14.8.3.1 Input signals
The trip value recorder function uses analog input signals connected to A1RADR to
A3RADR (not A4RADR).
14.8.4 Operation principle
Trip value recorder calculates and presents both fault and pre-fault amplitudes as well
as the phase angles of all the selected analog input signals. The parameter
ZeroAngleRef points out which input signal is used as the angle reference.
When the disturbance report function is triggered the sample for the fault interception
is searched for, by checking the non-periodic changes in the analog input signals. The
channel search order is consecutive, starting with the analog input with the lowest
number.
When a starting point is found, the Fourier estimation of the pre-fault values of the
complex values of the analog signals starts 1.5 cycle before the fault sample. The
estimation uses samples during one period. The post-fault values are calculated using
the Recursive Least Squares (RLS) method. The calculation starts a few samples after
the fault sample and uses samples during 1/2 - 2 cycles depending on the shape of the
signals.
If no starting point is found in the recording, the disturbance report trig sample is used
as the start sample for the Fourier estimation. The estimation uses samples during one
cycle before the trig sample. In this case the calculated values are used both as pre-
fault and fault values.
The name of the analog signal that appears in the Trip value recorder function is the
user-defined name assigned when the IED is configured. The same name is used in the
Disturbance recorder function .
Section 14
1MRK 504 135-UEN A
Monitoring
478
Technical manual