Instruction manual
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AQ G3x7 Generator protection IED
89 (211
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Figure 3-52: Third harmonic undervoltage independent time characteristic
t
OP
(seconds) theoretical operating time if G < G
S
, according to parameter setting value,
G
measured value of the characteristic quantity, Fourier third harmonic of the neutral
voltage,
G
S
setting value of the characteristic quantity.
Structure of third harmonic undervoltage protection
Figure below shows the structure of the definite time third harmonic undervoltage protection
(HIZ64) algorithm.
Figure 3-53: Structure of third harmonic undervoltage protection.