ABB Relion 650 Series Technical Manual page 222

Section 6
Current protection
The BLOCK signal is a general purpose blocking signal of the pole discrepancy protection. It can be
connected to a binary input in the IED in order to receive a block command from external devices
or can be software connected to other internal functions in the IED itself in order to receive a block
command from internal functions. Through OR gate it can be connected to both binary inputs and
internal function outputs.
If the pole discrepancy protection is enabled, then two different criteria can generate a trip signal
TRIP:
• Pole discrepancy signaling from the circuit breaker.
• Unsymmetrical current detection.
6.13.7.1 Pole discrepancy signaling from circuit breaker
If one or two poles of the circuit breaker have failed to open or to close (pole discrepancy status),
then the function input EXTPDIND is activated from the pole discrepancy signal in figure 113. After
a settable time
protection.
6.13.7.2 Unsymmetrical current detection
Unsymmetrical current indicated if:
• any phase current is lower than
• the highest phase current is greater than
If these conditions are true, an unsymmetrical condition is detected. This detection is enabled to
generate a trip after a set time delay
circuit breaker has received a command to open trip or close and if the unbalance persists. The
200 ms limitation is for avoiding unwanted operation during unsymmetrical load conditions.
The pole discrepancy protection is informed that a trip or close command has been given to the
circuit breaker through the inputs CLOSECMD (for closing command information) and OPENCMD
(for opening command information). These inputs can be connected to terminal binary inputs if
the information are generated from the field (that is from auxiliary contacts of the close and open
push buttons) or may be software connected to the outputs of other integrated functions (that is
close command from a control function or a general trip from integrated protections).
6.13.8 Technical data
Table 137: CCRPLD (52PD) technical data
Function
Operate value, current
asymmetry level
Reset ratio
Time delay
216
tTrip , a 150 ms trip pulse command TRIP is generated by the pole discrepancy
CurrUnsymPU of the highest current in the three phases.
tTrip if the detection occurs in the next 200 ms after the
Range or value
(0-100) %
>95%
(0.000-60.000) s
© Copyright 2011 ABB Power Grids. All rights reserved
CurrRelPU of IBase .
Accuracy
± 1.0% of I
n
-
± 0.5% ± 25 ms
1MRK 506 326-UUS B
M13946-18 v4
M13946-21 v4
M13279-1 v6
Line distance protection REL650
Technical manual