ABB REG670 Commissioning Manual page 217

1MRK 502 073-UUS A
Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062
Commissioning manual
4. Inject pure negative sequence current, that is, phase currents with exactly same
magnitude, reversed sequence and exactly 120° phase displaced into the IED with
an initial value below negative sequence current pickup level. No output signals
should be activated.
Note: If it is difficult to obtain pure negative sequence current for the secondary
injection test, a current corresponding to the two phase short-circuit condition can
be used. A two phase short-circuit gives a negative sequence current of a
magnitude: magnitude = (1/√3) · fault current.
5. Increase the injected current and note the value at which the step 1 of the function
operates. Pickup signal PU_ST1 must be activated when amplitude of the
negative sequence current lies slightly above the pickup level I2-1>.
Corresponding trip signals TRST1 and TRIP is activated after the pre-set time
delay has expired.
Note: Block or disable operation of step 2 when testing step 1 if the injected
current activates the step 2.
6. Decrease the current slowly and note the reset value.
7. Connect a trip output contact to a timer.
8. Set the current to 200 % of the pickup level of the step 1, switch on the current
and check the definite time delay for trip signals TRST1 and TRIP. Once the
measured negative sequence current exceeds the set pickup level I2-1>, the
settable definite timer t1 starts to count and trip signals is released after the set
time delay has elapsed. The same test must be carried out to check the accuracy
of definite time delay for ALARM signal.
Note: The output ALARM is operated by PICKUP signal.
9. If inverse time is selected the trip signals TRST1 and TRIP operates after a time
corresponding to the formula:
This means that if current jumps from 0 to 2 times pickup and negative sequence
capability value of generator K1 is set to 10 sec and current pickup level I2-1> is
set to 10% of rated generator current, then TRST1 and TRIP signals operates at
time equal to 250 s ± tolerance.
10. Repeat the above-described tests for the step 2 of the function excluding the
inverse time testing.
11. Finally check that pickup and trip information is stored in the event menu.
Testing functionality by secondary injection
1
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
I 2 1
− >
 

 
 100 

[ ]
t s
=

(
Multiple of Pickup



Section 13


2


⋅ ⋅ K
2

)



211