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Objects and Methods : Pumped Storage Reservoir : User Methods : Ramping
Ramping
This category allows you to model the cost of turbine ramping, the cost of changing the turbine release from one timestep to the next.
* None
This is the default method for this category. No new slots are instantiated, and no calculations are performed.
* Track Ramping
In this method the user assigns a unit cost to turbine ramping, a cost per unit change in flow from one timestep to the next. The method then calculates the change in turbine release and the associated ramping cost. The unit cost is the same for ramping up and ramping down.
Slots Specific to This Method
 Ramping Cost
Type: Series
Units: Value
Description: The total cost of turbine ramping for the timestep.
Information: This is the Unit Ramping Cost multiplied by the change in turbine release from one timestep to the net.
I/O: Output only
 Turbine Decrease
Type: Series
Units: Flow
Description: The difference between Turbine Release at the previous timestep and the current timestep when Turbine Release decreases from the previous timestep
Information: If Turbine Release at the current timestep is greater than at the previous timestep, the value is zero.
I/O: Output only
 Turbine Increase
Type: Series
Units: Flow
Description: The difference between Turbine Release at the current timestep and the previous timestep when Turbine Release increases from the previous timestep
Information: If Turbine Release at the current timestep is less than at the previous timestep, the value is zero.
I/O: Output only
 Unit Ramping Cost
Type: Table 1x1
Units: Value per Flow
Description: The cost per unit change in Turbine Release from one timestep to the next
Information: There is a single value for Unit Ramping Cost (that is, the same unit cost for ramping up and ramping down)
I/O: Optional input; if not input or negative, defaults to zero
Method Details 
1. The method first checks for a value in the Unit Ramping Cost table slot.
2. If there is no input value, or if the value is negative, it sets the value to zero.
3. Then it checks if Turbine Release is valid for the current timestep and the previous timestep.
4. If Turbine Release at the current timestep is greater than or equal to the previous timestep, the following values are set:
    
    
    
5. Otherwise, the following values are set:
    
    
    
6. If Turbine Release is not valid at both the current and previous timesteps, then Turbine Increase, Turbine Decrease and Ramping Cost will all display NaN.
Revised: 08/02/2021