Manual 37278B GCP-30 Series - Genset Control
Page 26/174 © Woodward
Generator Current
Parameter 30
Current transf.
generator 0000/x
Generator CT's 10 to 7,000/{X} A
The input of the CT ratio is necessary in order to display and control the actual val-
ues. The CT ratio must be selected so that, at maximum power, at least 60 % of the
CT nominal current flows. A lower percentage may lead to malfunctions. Addition-
al inaccuracies in the control and monitoring functions also occur.
{x} = 1 A ....... Secondary current = 1 A at primary rated current = {X} A;
{x} = 5 A ....... Secondary rated current = 5 A at primary rated current = {X} A;
{X} ................ e.g. from the main series 10, 15, 20, 30, 50 or 75 A and the decimal
fractions and multiples of these or the corresponding secondary se-
ries with 25, 40 or 60 A.
Parameter 31
Power measuring
gen.------------
Generator power measurement singlephase / threephase
With regard to the measurement of generator power, single-phase or three-phase
measurement may be selected. If "single-phase power measurement" is set, the cur-
rent and the voltage in phase L1 are used for power measurement. If "three-phase
power measurement" is set, all three phase currents and the relevant voltages are
used for power measurement.
• single-phase power measurement: P = √3 × V
L12
× I
L1
× cosϕ.
• threephase power measurement:
P = V
L1N
× I
L1
× cosϕ + V
L2N
× I
L2
× cosϕ + V
L3N
× I
L3
× cosϕ.
NOTE
With a positive real power, a positive real current flows in the "k-l" direction in the CT. Positive reactive
power means that with a positive effective direction, inductive reactive (lagging) current flows in the ef-
fective direction. If the control is connected to the terminals of a generator and if the outgoing circuits
of the CT facing the generator are connected to "k", the unit shows a positive real power when the ge-
nerator supplies real power. In this regard, note the explanations in manual 37238.
Parameter 32
Rated power
generator 0000kW
Generator rated power 5 to 9,999 kW
Here the generator rated power is configured. The exact value of the generator
rated power is absolutely vital. Many measurement, control and monitoring func-
tions refer to this value (e.g. the percentage input for the power protection).
Parameter 33
Rated current
generator 0000A
Generator rated current 10 to 7,000 A
Here the generator rated current is configured (only the percentage inputs for cur-
rent protection refer to this parameter).