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Generator
Objects and Methods
Generator
A generator represents a single generating unit within the overall Power Plant Diversion (see “Power Plant Diversion”). A generator has an individual capacity, efficiency and rating. The purpose of each generator is to capture the characteristics of that generator.
General Slots
Slots that always appear for this object
Diversion Requested
Type: Series
Units: Flow
Description: The computed withdrawal request for this generator.
Information:  
I/O: Typically output, but could be input.
Depletion Requested
Type: Series
Units: Flow
Description: The computed consumption request for this generator.
Information:  
I/O: Typically output, but could be input.
User Methods
Diversion and Consumption Request
This category is used to specify how the Diversion and Depletion Requested will be computed.
* None
No diversion or depletion requested will be computed. You can input the requests as needed.
* Power Generator Requests
The Power Generator Requests method is executed at the beginning of the run (on each timestep in the run) to compute the diversion and depletion requests based on temperature lookups to get the capacity and request slot values.
Slots Specific to This Method
Generator Operating Factors
Type: Table
Units: Temperature, Temperature, Fraction, Fraction
Description: A table relating Dry Bulb Temperature (C), Wet Bulb Temperature (C) versus Capacity Percentage (%) and Efficiency (%).
Information: This is a 3D table (with two Y columns) of the following form.
 
Dry Bulb Temperature (C)
Wet Bulb Temperature (C)
Capacity Fraction (%)
Efficiency (%)
20
20
70
60
20
30
65
50
20
40
60
50
25
20
70
59
25
30
64
50
25
40
59
50
30
20
69
51
30
30
63
49
30
40
57
48
I/O: Required Input
Generator Maximum Rates
Type: Table
Units: Temperature, Vol/Energy, Vol/Energy
Description: A table relating Dry Bulb Temperature (C), Max Withdrawal Rate (Vol/Energy) and Max Consumption Rate (Vol/Energy)
Information: This is a two dimensional table with two Y columns.
I/O: Required input
Name Plate Rating
Type: Scalar
Units: Power
Description: The maximum power that can be produced.
Information:  
I/O: Required Input
Wet Bulb Temperature
Type: Series
Units: Temperature
Description: The average wet bulb temperature (Celsius) for the timestep.
Information:  
I/O: Specified as input or via a rule
Dry Bulb Temperature
Type: Series
Units: Temperature
Description: The average dry bulb temperature (Celsius) for the timestep.
Information:  
I/O: Specified as input or via a rule
Specified Withdrawal Request
Type: Series
Units: Volume per Energy
Description: The specified withdrawal request. This value, if specified, overrides the computed max withdrawal request.
Information:  
I/O: Optional input or specified via rule. Can remain unspecified.
Specified Consumption Request
Type: Series
Units: Volume per Energy
Description: The specified consumption request. This value, if specified, overrides the computed max consumption request.
Information:  
I/O: Optional input or specified via rule. Can remain unspecified.
Capacity Fraction
Type: Series
Units: Fraction
Description: The computed fraction of the capacity.
Information:  
I/O: Output Only
Efficiency
Type: Series
Units: Fraction
Description: The computed power efficiency
Information: This value is presented for information only. It is not used in any calculations.
I/O: Output only
Adjusted Capacity
Type: Series
Units: Power
Description: The maximum power that can be produced by this generator, after adjusting for capacity fraction.
Information:  
I/O: Output only
Max Withdrawal Request
Type: Series
Units: Volume per Energy
Description: The maximum volume per energy for this generator.
Information:  
I/O: Output Only
Max Consumption Request
Type: Series
Units: Volume per Energy
Description: The maximum consumption rate for this generator.
Information:  
I/O: Output Only
This method is executed at the beginning of the run for all timestep in the run period. The required computations at each timestep include:
1. Look up the specified Wet Bulb Temperature and Dry Bulb Temperature on the Generator Operating Factors table to get the Capacity Fraction and Efficiency. Compute the Adjusted Capacity, as follows:
Adjusted Capacity = Name Plate Capacity * Capacity Fraction
2. Look up the specified Dry Bulb Temperature on the Generator Maximum Rates table to get Max Withdrawal Request and Max Consumption Request.
3. Next, compute the Diversion Requested. If the Specified Withdrawal Request is valid,
Diversion Requested = Adjusted Capacity * Specified Withdrawal Request * timeConversion
Else
Diversion Requested = Adjusted Capacity * Max Withdrawal Request * timeConversion
4. Similarly, compute the Depletion Requested. If the Specified Consumption Request is valid,
Depletion Requested = Adjusted Capacity * Specified Consumption Request * timeConversion
Else
Depletion Requested = Adjusted Capacity * Max Consumption Request * timeConversion
The time conversion is necessary because the internal units for the requests is m3/MWH while the internal volume for flow is cms. Thus the timeConversion = 1hr/3600s.
Dispatch Methods
There are no dispatch methods on the Generator.
Revised: 06/03/2019