See Also
The following options are all contained on the Island-Based AGC tab after choosing the Power Flow Solution page of the Simulator Options.
The Island Based AGC options allow the user to choose to dispatch generation by island instead of by area or super area. The options available for dispatch here are:
Enable Island-based Automatic Generation Control (AGC)
When this option is selected, Island-Based AGC is being used, and area and super area dispatch options are ignored.
Island AGC Tolerance
This sets the AGC tolerance in MW for the real power balance of each island. Generation must equal load plus losses plus DC line exports in each island. If necessary, each island slack bus output will vary during the Power Flow (Inner) Loop solution to maintain the real power balance for the island. If it varies more than the specified tolerance and if a form of Island-based AGC is specified, then adjustments to AGCable units will be made in the MW Control (Outer) Loop according to the selected Island-based AGC option.
Use Participation Factors of individual generators
When selected, the island-based AGC is used, based on the individual participation factors of each generator within the island. Area and super area ACE requirements will be ignored, and all generators in the island will be dispatched to serve load, losses, and any DC transfers to other islands.
If all generators with AGC = YES have participation factors also equal to 0.0, then all make-up power will come from the island slack bus.
Calculate Participation Factors from Area Make Up Power Values
The AGC will dispatch generation by using area make up power values, instead of by individual participation factor. What this means is that each area will be assigned a make up power value, similar to assigning a participation factor to a generator. Based on the make up power value of each area in the island, the amount of the generation dispatch needed will be divided amongst each area based on its value. Higher values will account for more of the generation dispatch than areas with smaller values. Then within each area, the generation dispatch is handled on an individual generator participation factor basis, where each generator will account for a portion of the dispatch that was assigned to its area.
To specify the make up power values for each area, click on the Specify Area Make Up Power Values button. Note that these settings are the same as those used by Contingency Analysis Options Make Up Power, therefore changing these values will affect the contingency analysis.
For example, three areas have participation factors of 2, 1 and 1, respectively. If the total generation redispatch in the island is 100 MW, then area 1 will account for 2 / (2+1+1), or 50%, of the total. Therefore area 1 is expected to redispatch by 50 MW. If area 1 then has two generators with participation factors of 4 and 1, they will account for the 50 MW by picking up 4 / (4+1) and 1 / (4+1), or 80% and 20%, respectively, of the 50 MW needed from the area.
If all areas have CTG Make Up Gen equal to 0.0, then all make-up power will come from the island slack bus.
Dispatch using an Injection Group (Loads and Generators will respond)
Checking this option will allow for the island dispatch to be covered by change in generation and/or load defined in an injection group.
Additional options are available when dispatching based on an injection group:
Allow only AGC Units to Vary
If this option is checked, only units whose AGC status is turned on will be allowed to participate in the injection group dispatch.
Enforce unit MW limits
If checked, then each generator’s defined MW limits will be strictly adhered to during the redispatch.
Do not allow negative loads
When checked, loads included in the injection group are not allowed to drop below zero MW or MVAR load demand.
How should reactive power load change as real power load is ramped?
You can choose to keep the ratio of real and reactive power constant for each load that is included in the injection group, or you can specify a constant power factor that the MVAR value will be determined from when the MW value is changed.
Injection groups have their own set of options that can override the default options on this dialog if they are in use. See the Injection Group Specific Scaling Options topic for more information.