Application - ABB RELION 630 Series Technical Manual

1MRS757256 F
3.14.1.4
PML630/Compact Load-Shedding Solution
Technical Manual
Analog signal trigger
All analog signals are available for trigger purposes, whether they are recorded in the
disturbance recorder or not. The settings are Over trigger Ch, Under trigger Ch, Over
Trg Lev Ch and Under Trg Lev Ch.
The check of the trigger condition is based on peak-to-peak values. When this is
found, the absolute average value of these two peak values is calculated. If the average
value is above the threshold level for an overvoltage or overcurrent trigger, this trigger
is indicated with a greater than (>) sign with the user-defined name.
If the average value is below the set threshold level for an undervoltage or
undercurrent trigger, this trigger is indicated with a less than (<) sign with its name.
The procedure is separately performed for each channel.
This method of checking the analog start conditions gives a function which is
insensitive to DC offset in the signal. The operate time for this start is typically in the
range of one cycle, 20 ms for a 50 Hz network.
All under/over trig signal information is available on the LHMI and PCM600.
Post retrigger
Disturbance report function does not automatically respond to any new trig condition
during a recording, after all the signals set as trigger signals have been reset. However,
under certain circumstances the fault condition may reoccur during the post-fault
recording, for instance by automatic reclosing to a still faulty power line.
In order to capture the new disturbance it is possible to allow retriggering (Post-retrig
= "On") during the post-fault time. In this case a new, complete recording starts and,
during a period, run in parallel with the initial recording.
When the retrig parameter is disabled (Post-retrig = "Off"), a new recording does not
start until the post-fault (Post-trigger time or Recording time limit) period is
terminated. If a new trig occurs during the post-fault period and lasts longer than the
proceeding recording, a new complete recording is started.
Disturbance report function can handle at maximum 3 simultaneous disturbance
recordings.

Application

To get fast, complete and reliable information about disturbances in the primary and/
or in the secondary system, it is important to gather information on fault currents,
voltages and events. It is also important to have a continuous event-logging to enable
monitoring in an overview perspective. These tasks are accomplished by the
disturbance report function DRRDRE. The function provides a better understanding
of the power system behavior and related primary and secondary equipment during
and after a disturbance.
The analysis of the recorded data provides valuable information that can be used to
explain a disturbance, in changing IED setting plan, to improve existing equipment,
Section 3
Basic functions
83