Woodward HighPROTEC - V;F> - Volts;Hertz [24]

Protective Elements
V/f> - Volts/Hertz [24]
Available Elements
V/f>[1] ,V/f>[2]
This protective element of the device provides over-excitation protection for the generator and unit connected
transformers. It incorporates two elements that can be programmed to specific times and used to create traditional,
two-step over-excitation protection.
In addition, the protective elements can be programmed as inverse time elements to provide advanced protection
by approximating closely the combined generator/unit transformer over-excitation curve. Standard inverse time
curves can be selected along with a linear reset rate that may be programmed to match the specific machine
cooling characteristics.
The percent pickup is based on the Nominal Voltage and Frequency settings. The V/Hz function provides reliable
measurements of V/Hz up to 200% for a frequency range of 5 - 70 Hz.
Characteristic / Curve Shape: INV A
786 MCDGV4 DOK-HB-MCDGV4-2E
1 1.2 1.4 1.6 1.8 2
0.01
0.1
1
10
100
1000
10
3
1
0.3
0.1
Time To Trip [s]
Multiples of volts per hertz pickup
t-multiplier
t =
t-multiplier
-1
2
( )
V / Vn
V/f>
f / fN