Generator Piecewise Linear Cost Display

See Also

 

The Generator Piecewise Linear Cost Display presents detailed cost information for each generator in the case set to use a piecewise linear cost model. The Generator Piecewise Linear Cost Display is a class of Case Information Display and therefore can be used in a manner consistent with all other case information displays. It has a local menu from which you can print, copy, and modify its records as well as view the information dialog of its associated generators. The Quick Power Flow List and Bus View Display tools are available for finding more information on the generator’s terminal bus. You can also sort the generator records by clicking on the heading of the field by which you want to sort. Additionally, you can choose to restrict the records shown by the Generator Piecewise Linear Cost Display according to the constraints of the area/zone/owner filters. Finally, you can use the local menu’s Insert and Delete options when the application is in Edit Mode to insert a new generator into the case or to delete an existing generator.

To show the generator piecewise linear cost display, select Network > Generators > Cost Curves Linear in the Model Explorer.

 

By default, the generator records display contains the following fields:

Number, Name

Number and name of bus to which the generator is attached.

Area Name of Gen

Name of the area to which the generator belongs. The generator can belong to an area which is different than the area of which its terminal bus is a member.

ID

Alphanumeric ID used to distinguish multiple generators at the same bus; ‘1’ by default.

Status

The Open / Closed status of the generator. This is a toggleable field.

AGC

Designates whether the generator’s real power output is governed by automatic generation control. If the AGC field is set to Yes, the generator is on automatic generation control (AGC). When a generator is on AGC, its real power output can be varied automatically. Usually the purpose for AGC is to keep the area interchange at a desired value. You can click on this field to toggle its value (except in Viewer). Please see Area Control for more details.

Gen MW

Current real power output of the generator.

Min MW

Minimum MW output of the generator.

Max MW

Maximum MW output of the generator.

Fuel Cost

The fuel cost of the type of fuel for the generator.

Fuel Type

An informational field that can be set to the type of fuel the generator uses.

Unit Type

An informational field that can be set to reflect the type of unit the generator is, such as combined cycle, steam, hydro, etc.

Cost Shift $/MWh, Cost Multiplier

The cost shift and cost multiplier allow you to easily apply a shift to the cost function for the purpose of assessing how variations in bids impact profit. The cost function is affected based on the following equation:

(Original Cost Function + Cost Shift) * Cost Multiplier

Fixed Cost

The fixed operating cost of the generator.

MWh Break x, MWh Price x

The remainder of the display is populated with MWh Break and MWh Price pairs. These pairs define the break points of the piecewise linear curve. The MWh Break value is a MW output value of the generator. The MWh Price value is the corresponding marginal cost of producing an additional MW of power at that MW output level. Therefore entering the break points of the piecewise linear curve in this manner defines the slopes of the next section of the curve, starting at the current MW Break point and up to but not including the next defined break point. The last MWh Break and MWh Price pair defined will define the marginal price of the unit from that break point location to the maximum output of the generator.

An example is as follows:

MW	$/MWh
0	50	(row could be omitted)
100	50	(this value is used if previous row is omitted)
200	80
250	300
300	400