ABB Relion® Protection and Control REX640 Event log

Event log

To collect sequence-of-events information, the relay has a

nonvolatile memory capable of storing 1024 events with the

associated time stamps. The event log facilitates detailed pre

and post-fault analyses of feeder faults and disturbances. The

considerable capacity to process and store data and events in

the relay supports the growing information demand of future

network configurations.

The sequence-of-events information can be accessed either via

the LHMI or remotely via the communication interface of the

relay. The information can also be accessed locally or remotely

using the Web HMI.

Recorded data

The relay can store the records of the latest 128 fault events.

The records can be used to analyze the power system events.

Each record includes, for example, current, voltage and angle

values and a time stamp. The fault recording can be triggered

by the start or the trip signal of a protection block, or by both.

The available measurement modes include DFT, RMS and

peak-to-peak. Fault records store relay measurement values

when any protection function starts. In addition, the maximum

demand current with time stamp is separately recorded. The

records are stored in the nonvolatile memory.

Load profile

The load profile recorder stores the historical load data

captured periodically (demand interval). Up to 12 load

quantities can be selected for recording and storing in the

nonvolatile memory. The recordable quantities include

currents, voltages, power and power factor values. The

recording time depends on a settable demand interval

parameter and the amount of quantities selected. The

quantities' type and amount to be recorded are determined in

the application configuration. The recorded quantities are

stored in the COMTRADE format.

Trip circuit supervision

The trip circuit supervision continuously monitors the availability

and operability of the trip circuit. It provides open-circuit

monitoring both when the circuit breaker is in closed and in

open position. It also detects loss of circuit-breaker control voltage.

Self-supervision

The relay’s built-in self-supervision system continuously

monitors the state of the relay hardware and the operation of

the relay software. Any fault or malfunction detected is used for

alerting the operator.

A permanent relay fault blocks the protection functions to

prevent incorrect operation.