Measuring The Operate Value For The Negative Sequence Function - ABB REG670 Commissioning Manual

1MRK 502 073-UEN A
13.9.2.2
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Commissioning manual
Testing functionality by secondary injection
• The BLKUand BLKZ signals should appear without any time delay.
• All undervoltage-dependent functions must be blocked.
5. Disconnect the dc voltage from the MCBOP binary input terminal.
6. Disconnect one of the phase voltages and observe the logical output signals
on the binary outputs of the IED.
BLKU and BLKZ signals should appear simultaneously wether the BLKU
and BLKZ reset depends on the setting SealIn "on" or "off". If "on" no reset,
if "off" reset.
7. After more than 5 seconds disconnect the remaining two-phase voltages and
all three currents.
• There should be no change in the high status of the output signals
BLKU and BLKZ.
• The signal 3PH will appear.
8. Establish normal voltage and current operating conditions simultaneously and
observe the corresponding output signals.
They should change to logical 0 as follows:
• Signal 3PH after about 25ms
• Signal BLKU after about 50ms
• Signal BLKZ after about 200ms

Measuring the operate value for the negative sequence function

Measure the operate value for the negative sequence function, if included in the
IED.
1. Simulate normal operating conditions with the three-phase currents in phase
with their corresponding phase voltages and with all of them equal to their
rated values.
2. Slowly decrease the measured voltage in one phase until the BLKU signal
appears.
3. Record the measured voltage and calculate the corresponding negative-
sequence voltage according to the equation (observe that the voltages in the
equation are phasors):
3 ⋅ U = U + a 2 ⋅
2 L 1
EQUATION707 V2 EN-US
Where:
U , U and U
L1 L 2 L3
IEC00000275 V1 EN-US
p ×
2
j
= × = -
a 1 e 0, 5
3
IECEQUATION00022 V2 EN-US
U + ⋅ a U
L2 L3
are the measured phase voltages
3
+
. j
2
Section 13
M1405-46 v12
(Equation 106)
225