Teleprotection With Earth Fault Protection - Siemens siprotec 7SA522 User Manual

Important for All
Schemes:
8.3.6.2

Teleprotection with Earth Fault Protection

Directional Com-
parison Pickup,
Unblocking
7SA522 Manual
C53000-G1176-C119-2
Naturally the corresponding transmit and receive signals must also be assigned to the
corresponding binary output and input.
Communication between the line ends is necessary.
On the transmitting end, a fault in zone Z1 must be simulated. This can be achieved
with secondary injection test equipment.
Subsequently, on the receiving end, a fault inside Z1B, but outside Z1 is simulated.
Tripping takes place immediately, (or in T1B), without signal transmission only in a
higher distance stage.
This test must be carried out at both line ends, on a three terminal line at each line end
for each transmission path.
If the earth fault protection was disabled for the signal transmission tests, it may be re-
enabled now. If setting parameters were changed for the test (e.g. mode of the echo
function or timers for unambiguous observation of sequences), these must now be re-
set to the prescribed values.
If the signal transmission path for the earth fault protection is the same path that was
already tested in conjunction with the distance protection according to Sub-section
8.3.6.1, then this Sub-section 8.3.6.2 is of no consequence and may be omitted.
For the functional check of the earth fault protection signal transmission, the distance
protection should be disabled, to avoid interference of the tests by signals from the dis-
tance protection: address  )&7 'LVWDQFH = 2)).
Prerequisites: 7HOHSURWHFWLRQ IRU (DUWK IDXOW RYHUFXUU 7HOHSURW
() in address  (Section 5.1) must be set to one of the comparison schemes
utilizing a release signal, i.e. 'LU&RPS3LFNXS or 8QEORFNLQJ; in addition the set-
ting in address  must be set to )&7 7HOHS () 21. Naturally, the correspond-
ing send and receive signals must be assigned to the corresponding binary output and
input. For the echo function, the echo signal must be marshalled separately to the
transmit output.
A simple check of the signal transmission path from one line end is possible via the
echo circuit if these release techniques are used. The echo function must be activated
at both line ends i.e. address  must be set to )&7 :HDN ,QIHHG = (&+2 RQO\;
with the setting (&+2 DQG 75,3 a trip may result at the line end opposite to the test
location!
An earth fault is simulated in the direction of the line. This may be done with secondary
injection test equipment. As the device at the opposite line end does not pick up, the
echo function comes into effect there, and consequently a trip command is issued at
the line end being tested.
If no trip command appears, the signal transmission path must be checked again, es-
pecially also the assignment of the echo signals to the transmit outputs.
This test must be carried out at both line ends, in the case of three terminal lines at
each end for each signal transmission path.
The functioning of the echo delay time and monitoring of the circuit breaker switching
status must also be tested at this time if this has not already been done under 8.3.6.1
(the operation of the protection at the opposite line end is checked):
Installation and Commissioning
8-35