VAMP 52 - IEEE2 inverse time operation

2.23 Inverse time operation 2 Protection functions Technical description
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Figure 2.23.1-7 ANSI/IEEE long
time extremely inverse delay
Figure 2.23.1-8 ANSI/IEEE
moderately inverse delay
Figure 2.23.1-9 ANSI/IEEE short
time inverse delay
Figure 2.23.1-10 ANSI/IEEE short
time extremely inverse delay
IEEE2 inverse time operation
Before the year 1996 and ANSI standard C37.112
microprocessor relays were using equations approximating the
behaviour of various induction disc type relays. A quite popular
approximation is Equation 2.23.1-3, which in VAMP relays is
called IEEE2. Another name could be IAC, because the old
General Electric IAC relays have been modeled using the same
equation.