Voltage Regulation Submenu - Kohler 14EKOZD Operation

2.11.4 Voltage Regulation Submenu

Note:
Have setup and adjustments of the Decision-Maker
The setup and adjustments are password protected.
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The Decision-Maker 3500 controller has a built-in voltage regulation function. This means that no external voltage regulator is
necessary. The voltage regulation of the controller uses Root Mean Square (RMS) sensing for fast response to changes in
indicated and regulated voltages resulting in excellent regulation accuracy.
The descriptions of the voltage regulator adjustments and features follow.
Voltage Adjust. The voltage adjust allows the user to enter the desired generator set output level. The voltage regulator controls
the average of the three output phase voltages to this target in a three phase configuration, and L1L2 voltage to this target in a
single phase configuration.
Submenus display the individual line-to-line voltages and the individual phase voltages. These voltages are for reference only
and are relevant in unbalanced load conditions. The voltage adjust setpoint can be changed to accommodate an important
phase in an unbalanced system.
Target Voltage. The voltage that the Decision-Maker
Volts/Hz. The excitation control system includes an under-frequency unloading feature. This is sometimes referred to as Volts-
per-Hertz or V/Hz. When the frequency drops below a certain value, the output voltage is reduced to decrease engine load,
allowing the engine speed to recover more quickly. The output voltage reduction is based on the frequency.
Volts per Hz Settings. The amount of voltage reduction can be adjusted to achieve the desired transient response of the engine
and alternator system. The V/Hz function will use the following parameter settings:
• V/Hz Setpoint (Hz)
• V/Hz Slope (%/Hz)
• V/Hz reduction limit (fixed at 50% of rated voltage)
Volts per Hz Adjustment. The V/Hz settings can be changed using the PC-based setup program or at the front panel using the
password. The setup program will read current settings to determine a similar function when making changes to alternator
connections, system voltages or operating frequency.
Volts/Hz Setpoint. This adjustment affects the voltage droop (volts per Hz) when load is applied and underfrequency occurs.
The volts/Hz setpoint setting defines the threshold below which the underfrequency unloading is active. Any frequency below
the setpoint causes the voltage to drop thus reducing the load allowing the engine speed to recover according to the volts/Hz
slope setting.
Engine speed recovery depends upon characteristics such as engine make, fuel type, load types, and operating conditions. The
volts/Hz setpoint setting is set at the factory to match the engine speed recovery characteristics for the application.
Volts/Hz Slope. This setting determines how much the voltage drops during an underfrequency condition. The Volts/Hz Slope
setting is set at the factory. Typically, applying a large electrical load causes a dip in engine speed and frequency. The voltage
regulator reduces voltage, allowing engine speed recovery. The volts-per-Hz setting determines the degree of unloading that
occurs for each 1 Hz decrease in frequency.
Voltage Droop at 100% kVAR (Reactive Droop). Reactive droop compensation provides reactive current flow adjustment in
the generator set when connected in paralleling applications. Reactive droop reduces excitation levels with increasing reactive
power. A reduced excitation level reduces generator set reactive power or generated VARs, improving reactive load sharing.
Enter the parameter as a percentage of system voltage when full-rated load with 0.8 power factor is applied. Any loads less than
full load force the voltage to drop by the ratio of reactive volt-amps (VARs) to rated VARs.
Voltage Gain Adjust. Regulator gain refers to the gain of the control system. Generally, the higher the gain the faster the system
responds to changes and the lower the gain, the more stable the system.
If the voltage is slow to recover when loads are applied or removed, increase the regulator gain. If the voltage is unstable,
decrease the regulator gain.
The voltage regulator value is reviewable at all times and provides the ability to fine adjust voltage. Changing the system voltage
or replacing the circuit board typically requires a voltage adjustment.
TP-7044 6/23
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3500 controller performed only by an authorized Kohler distributor/dealer.
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3500 controller is trying to achieve including droop and parallelling bias.
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