Voltage Droop
The amount of reactive droop is entered here. The droop is entered as a percentage of system voltage when a fully rated load at 0.8 PF is applied. The entry may be made with resolution as fine as
The present voltage droop setting is displayed for reference. The display may change if this value is changed via remote communication.
VAR Control Enable
In order for the VAR control function to operate, it must be enabled. Entering YES at this menu will turn the feature on. Because the function is designed to operate while the generator set is in parallel with the utility, VAR control also requires the proper indication that all tying circuit breakers are closed. This is done through the
Because VAR control cannot be enabled at the same time that PF control is enabled, turning VAR control on (ENABLED) when PF control is enabled turns the PF control off (DISABLED).
KVAR Adjust
Using the kVAR adjust sets the desired operating value for the generator set’s reactive load when the generator set operates in a utility paralleling application. The desired generator set load is entered directly as kVARs. The value entered may be as low as zero or as high as the rated value (rated kW x 0.75). Any entry beyond the rated value will not be accepted, and a RANGE ERROR message will be displayed.
The default value for kVAR adjust is zero. Each time the system’s rated kW is changed, the kVAR adjust will revert to zero. The displayed kVAR setting may change if the kVAR setting is changed via other inputs.
Generating/Absorbing
While operating in the VAR control mode, the reactive load on the generator set may be specified to be out of GENERATING or into ABSORBING the generator set. Specifying the VAR type or direction is done through the GENERATING/ABSORBING menu. Because the normal flow of reactive current is out of the generator set, the default value is GENERATING. If ABSORBING is desired, a NO entry at this menu will change the control mode to ABSORBING. When ABSORBING is selected, another NO entry will revert the control mode back to GENERATING. It is assumed that this mode will not be changed when the generator set is running. An attempt to change the mode while running will return a RANGE ERROR message. The generator set will need to be shut down in order to change this setting.
PF Adjust
Use the PF adjust to set the desired operating relationship for the generator set’s output voltage and current when the generator set is connected in parallel with the utility. The excitation is regulated to maintain a PF equal to the entered value. The value entered may be as low as 0.7 for leading PFs or as low as 0.6 for lagging PFs. Any entries below these limits will cause a RANGE ERROR message to display.
The upper limit for PF adjust is 1.0 and the default value is 0.8 lagging. Each time the system’s rated kW is changed, the PF adjust will revert to this default value. The PF adjust display setting may change if the PF adjust is changed via other inputs.
Lagging/Leading
It is possible to select either a leading or lagging PF for utility parallel applications. The selected mode is displayed. A NO entry switches the controller to use the other reference. Because the most common mode of operation will be with a lagging PF, LAGGING is the default value. Because this mode should not be changed while the generator set is running, attempting to change this mode during operation will return a RANGE ERROR message. Always shut down the generator set to change the lagging/leading mode setting.
Appendix 207 |
