Woodward GCP-20 Series User Manual

Manual 37128A GCP-20 Series - Genset Control
© Woodward Page 55/190
Load and/or Var Sharing
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Control guarantees that, in every operating condition (mains parallel operation, isolated operation in parallel with
other gensets or back synchronization of the busbar to the mains), the active power (in reference to the relevant
nominal load) is evenly distributed over all gensets operating in parallel to the busbar.
Mains parallel opera-
tion with mains trans-
fer regulation
Each controller involved in distribution control influences the genset to which it is assigned
in such a manner that the active power set at the mains interchange point (main control vari-
able) remains constant. All units are interlinked via a CAN bus, via which any deviation in
active power (generator power) can be determined for each genset. This control variable is
taken into consideration on controlling the interchange load. The weighting, with which the
secondary and the main control variable (= "reference variable") are processed, can be set
via a factor. In controlled state, the set active power flows at the mains interchange point,
whereby the total active power is subdivided equally amongst those gensets involved in dis-
tribution control. If a constant power C has been input as the set point value for a genset, this
is no longer involved in distribution control.
Isolated operation in
parallel with other gen-
sets
Each controller involved in distribution control influences the genset to which it is assigned
in such a manner that the active power set at the mains interchange point (main control vari-
able) remains constant. All units are interlinked via a CAN bus, via which any deviation in
active power (generator power) can be determined for each genset. This control variable is
taken into consideration on controlling the frequency. The weighting, with which the secon-
dary and the main control variable (= "reference variable") are processed, can be set via a
factor. In controlled state, the isolated system has the set rated frequency, whereby the total
active power (in reference to the relevant nominal power) is subdivided equally amongst
those gensets involved in distribution control.
Resynchronization of
the busbar to the mains
Distribution is carried out according to the type of isolated operation. The set point value for
the frequency is however calculated from the mains frequency (df max × 0.5 + f
mains
, general
synchronization argument; 0.1 Hz). The relay outputs "Mains power circuit breaker CLOSE"
for all units can be switched in parallel.
Prerequisites
It is mandatory that the rated system frequencies, the add-on/shed-off parameters, and the
power circuit breaker logics are always adjusted to the same values for all units of the distri-
bution control system.
Description of the in-
terface for the distribu-
tion control system
Distribution control is based on a multi-master-capable bus between the units. This structure
enables the parallel operation of up to 8 gensets.
To guarantee a trouble-
free operation, please
observe the following:
1. The bus length must not exceed 250 mtrs.
2. Each end of the bus must be terminated with terminating resistors which correspond to
the wave impedance of the bus cable (approx. 120 Ω).
3. The structure of the bus must be linear. Dead-end feeders are not permissible.
4. Shielded "Twisted-Pair" are to be preferred as bus cables (example: Lappkabel Unitronic
LIYCY (TP) 2×2×0.25, UNITRONIC-Bus LD 2×2×0.22).
5. The bus cable must not be installed near power cables.

Woodward GCP-20 Series Specifications

General

Brand	Woodward
Model	GCP-20 Series
Category	Control Unit
Language	English