ABB RELION REX640 Technical Manual page 1010

Protection functions
Mho circle entirely and the setting
the slip counter triggers also the Reset timer. All of the zone slip counters reset after
the set
blinder again, or on activation of the OPERATE output.
When the "Way out" or "Adaptive" option is selected, the breaker open time, if
known, can be incorporated to optimize breaker trip time when a way out trip
command is issued. The ideal time for the breaker to interrupt current is when the
swing angle approaches zero. If the swing angle is δ
outer blinder, the dynamic Trip delay, T
T
od
T
od
T
co
BrkopenTm Set
f
slip
The
a trip command to the time when the breaker receives the command. The function
uses the
to "0". If the
calculate a trip delay but uses the fixed
OPERATE output.
The slip frequency is calculated using
f
slip
f
slip
T
oi
δ
0
δ
I
The swing angles, δ
crossing the blinders. It is the difference in these quantities that is important for
determining the slip frequency.
If the "Adaptive" option is selected, after detecting an OSB condition, the function
further examines the slip frequency f
outer blinder (δ
way out. OPERATE is activated on the way in, entering the mho circle from an inner
blinder, if the relationship in
1010
Reset time has elapsed and the impedance does not cross into the outer
f ( T BrkropenTm
1 2
− ⋅ ⋅ +
slip co
=
f
2
⋅
slip
Dynamic Trip delay
The time for the impedance to travel from the center impedance line (where
the swing angle is π radians) to the outer blinder on the opposite side from
which it entered.
Breaker open time
Slip frequency
Breaker open time setting should include the time from when the relay issues
Breaker open time setting to determine the trip delay time if it is not set
Breaker open time is set to "0", the function does not dynamically
δ δ
−
i
0
=
π T
2
⋅ ⋅
oi
Slip frequency
The time for the impedance to pass from the outer to the inner blinder.
Swing angle at the outer blinder
Swing angle at the inner blinder
and δ
0
) to determine if the operate is asserted on the way in or on the
0
Zone 3 enable is also set to "Yes". Increment of
, can be set as shown in
od
)
Operate delay time before activating the
Equation 274
, are estimated from the measured impedance when
I
V dip time setting, and swing angle at the
,
slip
Equation 275
is true.
1MRS759142 F
when the impedance exits the
0
Equation 273
(Equation 273)
.
(Equation 274)
Technical Manual
.
REX640