8-2 9424200996
Auxiliary Overvoltage (59X) Protection BE1-11m
Sensing Configuration
When using the Vx input, setting the Aux VT Connection parameter provides the correct labeling of
settings and metering data found in BESTCOMSPlus and fault reports. The Aux VT Connection
parameter set to AB, for example, will display the metering data as AB in fault records and display the
pickup setting as Vpp in BESTCOMSPlus. See Table 8-1 for a full list of possible settings. The Aux VT
Connection parameter is found on the System Parameters/Sensing Transformers settings screen in
BESTCOMSPlus. For more information on the auxiliary VT setup, see the Configuration chapter.
Table 8-1. Auxiliary VT Configuration
Vx Fundamental, Vx Third Harmonic
Vx Fundamental, Vx Third Harmonic
Vx Fundamental, Vx Third Harmonic
Timings
The timing mode can be set for definite or inverse.
Inverse
When inverse timing is selected, a Curve setting is provided to select programmable or table curves. The
user can select integrating reset timing to make the protective element use integrated reset and emulate
an electromechanical induction disk reset characteristic. The overvoltage inverse time curve with default
constants is shown in the Time Curve Characteristics chapter.
Programmable Curves
The programmable curve can be used to create a custom curve by selecting constants in the inverse time
characteristic equation. When curve P is selected, the constants used in the equation are those defined
by the user. Characteristics for trip and reset programmable curves are defined by Equation 8-1 and
Equation 8-2. Definitions for these equations are provided in Table 8-2.
=
−
+
Equation 8-1. Time Characteristics for Trip
=
|
2
−1
|
Equation 8-2. Time Characteristics for Reset
Table 8-2. Definitions for Equation 8-1 and Equation 8-2
Time that the 59X-x function will take to time out and trip.
Time dial setting for the 59X-x function.
M Multiple of pickup
Measured current in multiples of pickup. The timing algorithm has
a dynamic range of 1 to 3 times pickup.
A
Constant specific to
selected curve
Affects the effective range of the time dial.
B
Constant specific to
selected curve
Affects a constant term in the timing equation. Has greatest effect
on curve shape at high multiples of tap.
C
Constant specific to
selected curve
Affects the multiple of PU where the curve would approach
infinity if allowed to continue below pickup. Has greatest effect on
N
Exponent specific to
selected curve
Affects how inverse the characteristics are. Has greatest effect
on curve shape at low to medium multiples of tap.
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