TP-6862 6/14
60 Section 9 Paralleling Generator Sets
Voltage Bias
is the amount that the controller is
attempting to adjust the output voltage (100% bias
= +10% on the output voltage, --100% = --10% on
the output voltage). The controller adjusts the
voltage bias to match the generator voltage to the
bus voltage.
Note:
The Voltage Bias can also be controlled by
an external device if the External Bias Inputs
Enabled parameter is true, the Stand Alone
Operation parameter is false, no generators
are visible on the PGEN communications
channel, and the voltage applied to the
voltage bias input is between 0.5V and 4.5V.
The External Voltage Bias Input (VBP and VBN) is
a voltage measuring channel capable of reading
from --10V to 30V DC. The input is normally pulled
down to --3.3V, but can be overridden by applying a
voltage to the input.
The voltage that the controller sees on the voltage
measuring channels is visible in the
Analog
Voltage Input Metered Relative Value
under the
Programmable Analog Voltage Input 107
parameter heading. The input is polarity sensitive.
The Voltage Bias is interpreted by the controller as
shown in Figure 9-2
Range: -100.00% – 100.00%
Default: 0.00%
**Not Writable**
Figure 9-2
Voltage Bias
Synchronizing
Before a generator set can operate in parallel with
another generator set, its electrical output must be
synchronized (matched) to the power source it will
parallel. The parameters that must be matched are:
D
Frequency
D
Phase Angle
D
Voltage
D
Phase Rotation
The synchronizer will issue a breaker close command
when the frequency difference, phase angle, and
voltage difference are within an acceptable range and
the phase rotation matches.
For PGEN paralleling, the synchronizing is handled
within the Decision-Maker
r
3500 controller.
For Remote Speed and Voltage Bias paralleling, the
synchronizing is handled by an external controller,
typically supplied on switchgear.
Real (kW) Load Control
When generator sets are running in parallel (electrically
connected), the load controller controls the generator
sets so each generator set is supplying its proportional
share of power to the load while maintaining rated
frequency. This is isochronous load sharing.
The load controller communicates (analog or digital) to
the other load controllers and determines how much
power each generator set should supply.
For PGEN paralleling, the load controller is within the
Decision-Maker
r
3500 controller.
For Remote Speed and Voltage Bias paralleling, the
load controller is performed by an external controller,
typically supplied on switchgear.
Reactive (kVAR) Control (Isolated Bus)
When generator sets are paralleled, the voltage output
of each generator set must be equal. Reactive power
control is needed between the generator sets to ensure
that each is supplying its share of the reactive load and
to minimize circulating currents. This can be done in one
of two ways:
1.
Active Control (Used in PGEN Paralleling and
Remote Speed and Voltage Bias Paralleling).
The reactive load controller communicates
(analog or digital) to the other reactive load
controllers to maintain the same proportional kVAR
output while maintaining the system’s nominal
voltage.
Summary of Contents for 33-125EFOZCJ
Page 2: ...TP 6862 6 14 2...
Page 8: ...TP 6862 6 14 8 Safety Precautions and Instructions Notes...
Page 10: ...TP 6862 6 14 10 Section 1 Introduction Notes...
Page 12: ...TP 6862 6 14 12 Section 2 Location and Mounting Notes...
Page 28: ...TP 6862 6 14 28 Section 5 Fuel System Notes...
Page 34: ...TP 6862 6 14 34 Section 6 Electrical System Notes...
Page 52: ...TP 6862 6 14 52 Section 7 Installation Drawings Notes...
Page 78: ...TP 6862 6 14 78 Section 9 Paralleling Generator Sets Notes...
Page 82: ...TP 6862 6 14 82...
Page 83: ...TP 6862 6 14 83...
