Design - ABB REL650 Technical Manual

1MRK 506 382-UEN A
6.4.7.5
Line distance protection REL650 2.2 IEC
Technical manual

Design

At every execution of the function the following is calculated: active power P,
reactive power Q, rotor angle ROTORANG, quantity UCOSPHI, the positive-
sequence current CURRENT and voltage VOLTAGE. All other quantities, that can as
well be read as outputs, are only calculated if the Z(R, X) enters the limit of reach
zone, which is a circle in the complex (R – X) plane. When the complex impedance
Z(R, X) enters the limit-of-reach region, the algorithm:
• determines in which direction the impedance Z moves, that is, the direction the
lens is traversed
• measures the time taken to traverse the lens from one side to the other one
If the traverse time is more than the limit 40 or 50 ms, a pole-slip is declared. If the
complex impedance Z(R, X) exits the lens on the same side it entered, then it is a
stable case and the protected machine is still in synchronism. If a pole-slip has been
detected, then it is determined in which zone the centre of oscillation is located. If
the number of actual pole-slips exceeds the maximum number of allowed pole-
slips in either of the zones, a trip command is issued taking care of the circuit
breaker safety.
Calculation of Calculation of
UPSRE UPSRE
R and X parts R and X parts
UPSIM UPSIM
of the complex of the complex
UPSMAG UPSMAG
positive- positive-
IPSRE IPSRE
sequence sequence
IPSIM IPSIM
impedance impedance
Z(R, X) Z(R, X)
LEFT LEFT
Motor losing Motor losing
step ? step ?
Calculation of Calculation of
positive- sequence positive- sequence
active power P, active power P,
reactive power Q, reactive power Q,
rotor angle rotor angle
ROTORANG ROTORANG
and and
UCOSPHI UCOSPHI
IEC10000116 V3 EN-US
Figure 68: OOSPPAM Simplified function block
R R
X X
Z(R,X) Z(R,X)
Z(R,X) Z(R,X)
NO NO
within limit of within limit of Return Return
reach? reach?
YES YES
Z(R,X) Z(R,X)
NO NO
within lens within lens
Function alert Function alert
characteristic? characteristic?
YES YES
Z(R,X) Z(R,X)
Z(R,X) Z(R,X)
RIGHT RIGHT
exited lens exited lens
entered lens entered lens
on the left - hand on the left - hand
from? from?
side? side?
Generator losing Generator losing
step ? step ?
Was Was
traverse time traverse time
more than more than
50 ms? 50 ms?
P P
Q Q
Number Number
ZONE 2 ZONE 2
of pole- slips of pole- slips
UCOSPHI UCOSPHI
exceeded in exceeded in
a zone? a zone?
ROTORANG ROTORANG
Section 6
Impedance protection
GUID-1615F014-3529-45D0-813B-153754DED1C7 v3
NO NO
YES YES
NO NO
YES (pole - slip!) YES (pole - slip!)
>= 1 >= 1
NO NO
Open Open
circuit circuit
ZONE 1 ZONE 1
breaker breaker
safely safely
IEC10000116-3-en.vsd
R R
X X
UCOSPHI UCOSPHI
ROTORANG ROTORANG
SLIPFREQ SLIPFREQ
GENMODE GENMODE
MOTMODE MOTMODE
TRIP TRIP
TRIPZ1 TRIPZ1
TRIPZ2 TRIPZ2
147