Woodward HighPROtec MCDLV4, Руководство пользователя, Страница: 633 / 1275

Protective Elements
15%
The so-called transient time period directly after energizing strongly depends on the above mentioned influencing
parameter. Time spans from nearly zero to more than 15 seconds are known for special auto-transformer banks. A
typical setting of 2s is recommended for commonly used transformers.
t-Trans
Default (example)
1 s
All harmonic-generating events can occur to a different degree in one, two, or all three phases. That is why there is
a choice provided to restrain only those phases with harmonic content or restrain all three phases, which is
recommended for typical application, as long as knowledge of the grid and modes of operation do not prove another
choice.
Block mode
Default (example)
active
The Transient Monitor analyzes continuously the differential current signal. If it detects saturation ∣ m ∣
>
1 , it will
decide whether the saturation is caused by internal or external faults.
• External Faults: the sign of differential current and of slope are equal (both “-“ or both”+”).
• Internal Faults: the sign of differential current and slope are different (one “-“ and the other “+” or the other way
round).
If the saturation is caused by an internal fault, there will be no raising/stabilizing of the tripping curve. If the
saturation is caused by an external fault, the tripping curve will be raised by d(H,m).
CT Satur Monit
Default (example)
633 MCDLV4 DOK-HB-MCDLV4-2E
Idmax
Id
Pure sinusoidal waveform
t
Derivative
Derivative
real