Oscillation Suppression; Binary Outputs - ABB RELION 620 Series Technical Manual

Section 3
Basic functions
3.11.3
3.12
106
When a binary input is inverted, the state of the input is TRUE (1) when no control
voltage is applied to its terminals. Accordingly, the input state is FALSE (0) when a
control voltage is applied to the terminals of the binary input.

Oscillation suppression

Oscillation suppression is used to reduce the load from the system when a binary input
starts oscillating. A binary input is regarded as oscillating if the number of valid state
changes (= number of events after filtering) during one second is equal to or greater
than the set oscillation level value. During oscillation, the binary input is blocked (the
status is invalid) and an event is generated. The state of the input will not change when
it is blocked, that is, its state depends on the condition before blocking.
The binary input is regarded as non-oscillating if the number of valid state changes
during one second is less than the set oscillation level value minus the set oscillation
hysteresis value. Note that the oscillation hysteresis must be set lower than the
oscillation level to enable the input to be restored from oscillation. When the input
returns to a non-oscillating state, the binary input is deblocked (the status is valid) and
an event is generated.
Table 51: Oscillation parameter values
Parameter
Input osc. level
Input osc. hyst

Binary outputs

The protection relay provides a number of binary outputs used for tripping, executing
local or remote control actions of a breaker or a disconnector, and for connecting the
protection relay to external annunciation equipment for indicating, signalling and
recording.
Power output contacts are used when the current rating requirements of the contacts
are high, for example, for controlling a breaker, such as energizing the breaker trip and
closing coils.
The contacts used for external signalling, recording and indicating, the signal outputs,
need to adjust to smaller currents, but they can require a minimum current (burden) to
ensure a guaranteed operation.
The protection relay provides both power output and signal output contacts. To
guarantee proper operation, the type of the contacts used are chosen based on the
operating and reset time, continuous current rating, make and carry for short time,
breaking rate and minimum connected burden. A combination of series or parallel
contacts can also be used for special applications. When appropriate, a signal output
Values
2...50 events/s
2...50 events/s
1MRS757644 F
Default
30 events/s
10 events/s
620 series
Technical Manual