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Frequency Regulation
This category depends on selecting the Unit Power Table method, although in the future it might be enabled for other power methods. The frequency regulation methods model the provision of the frequency regulation ancillary service; that is, how the reservoir can be made available to flexibly follow a load demand within a specified range during a certain period in order to affect the frequency of the generated power.
* None
This is the default, do-nothing method; no regulation is modeled.
* Unit Frequency Regulation
Note:  Although you can select the method and slots are added, this method is not yet implemented.
When frequency regulation is scheduled, it allows the unit to follow the real time load. Exactly what will happen in real time is unknowable. This results in two sets of values at scheduling time, nominally scheduled power and turbine release. It is uncertain if the real time operators will actually use the service. At present, we distinguish between the nominal scheduled power (and turbine release) that the regulation is allowed to depart from and the expected power generation (and turbine release) that will take place when regulation is allowed. Both are important. The scheduled power sets the baseline for regulation and should be communicated to the power dispatchers. The expected power and release are more useful for coordinating a plant with the rest of the system.
Slots Specific to This Method
Many of these slots have column or row dimensions based on the number of units. The rows/columns of these slots are expanded at the beginning of the run to match the value in the Number of Units slot. When first configuring this method, the user must enter the Number of Units, then run the model (stepping through one timestep is enough) to grow the slots to the right dimensions.
 Unit Regulation Table
Type: TableSlot
Units: Length, Flow, Power, Flow, Power
Description: This table (not visible to the user) represents the available regulation (both up and down in terms of flow and power) for each unit at each point in the Unit Power Table.
Information: This table is calculated using data in the Unit Power Table and the Avoidance Zone Table (if applicable) and could be calculated automatically at beginning of run in simulation and/or optimization. This table consists of a block of six columns for each unit. The head and flow values should be the same as the Unit Power Table. The other four columns in the block are respectively Regulation Flow Up, Regulation Power Up, Regulation Flow Down, and Regulation Power Down. These values represent the minimum and maximum power achievable from the initial flow value without passing through an avoidance zone.We require that the heads in this table appear in the Unit Power Table as well.
I/O: Automatically calculated at beginning of run
 Unit Two Sided Regulation
Type: AggSeriesSlot
Units: Power
Description: The value is the two sided frequency regulation for the unit at that timestep.
Information: There is one column for each unit.
I/O: Input or Output
 Unit Regulation Up
Type: AggSeriesSlot
Units: Power
Description: The value is the frequency regulation up for the unit at that timestep.
Information: There is one column for each unit.
I/O: Input or Output
 Unit Regulation Down
Type: AggSeriesSlot
Units: Power
Description: The value is the frequency regulation down for the unit at that timestep.
Information: There is one column for each unit.
I/O: Input or Output
 Unit Possible Regulation Up
Type: AggSeriesSlot
Units: Power
Description: The value is the possible regulation up for the unit at that timestep.
Information: There is one column for each unit.
I/O: Input or Output
 Unit Possible Regulation Down
Type: AggSeriesSlot
Units: Power
Description: The value is the possible regulation down for the unit at that timestep.
Information: There is one column for each unit.
I/O: Input or Output
 Unit Flow Addition For Regulation
Type: AggSeriesSlot
Units: Flow
Description: The value is the additional release required to reach the frequency high point for the unit at that timestep.
Information: There is one column for each unit. This value is typically returned from optimization and set via a rule.
I/O: Rule
 Unit Flow Reduction For Regulation
Type: AggSeriesSlot
Units: Flow
Description: The value is the reduction in release required to reach the frequency low point for the unit at that timestep.
Information: There is one column for each unit. This value is typically returned from optimization and set via a rule.
I/O: Rule
 Unit Scheduled Mechanical Power
Type: AggSeriesSlot
Units: Power
Description: The value is the scheduled mechanical power generation, before subtracting regulation (or reactive power) for the unit at that timestep.
Information: There is one column for each unit.
I/O: Output only
 Unit Scheduled Turbine Release
Type: AggSeriesSlot
Units: Flow
Description: The value is the turbine flow which corresponds to the Unit Scheduled mechanical Power for the unit at that timestep.
Information: There is one column for each unit.
I/O: Output only
 Unit Operating Cost Per Regulation Table
Type: TableSlot
Units: Value ($)
Description: For each generating unit, this is the cost per unit of regulation.
Information: There is one row for each unit.
I/O: Input
 Unit Operating Cost
Type: AggSeriesSlot
Units: Value ($)
Description: This is the total cost of using a unit for regulation incurred during the run.
Information: There is one column for each unit.
I/O: Output
 Operating Cost
Type: AggSeriesSlot
Units: Value ($)
Description: The value is the sum of the unit operating costs.
Information: This is an existing slot with only one column.
I/O: Output only
 Regulation
Type: SeriesSlot
Units: Power
Description: Total regulation for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Two Sided Regulation.
I/O: Output only
 Plant Regulation Up
Type: SeriesSlot
Units: Power
Description: Total regulation up for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Regulation Up.
I/O: Input or Output
 Plant Regulation Down
Type: SeriesSlot
Units: Power
Description: Total regulation down for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Regulation Down.
I/O: Input or Output
 Plant Possible Regulation Up
Type: SeriesSlot
Units: Power
Description: Total possible regulation up for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Possible Regulation Up.
I/O: Output only
 Plant Possible Regulation Down
Type: SeriesSlot
Units: Power
Description: Total possible regulation down for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Possible Regulation Down.
I/O: Output only
 Plant Flow Addition For Regulation
Type: SeriesSlot
Units: Flow
Description: Total additional turbine release required in order to reach the frequency regulation high point for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Flow Addition For Regulation.
I/O: Output only
 Plant Flow Reduction For Regulation
Type: SeriesSlot
Units: Flow
Description: Total reduction in turbine release required in order to reach the frequency regulation low point for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Flow Reduction For Regulation.
I/O: Output only
 Plant Scheduled Mechanical Power
Type: SeriesSlot
Units: Power
Description: Total scheduled mechanical power for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Scheduled Mechanical Power.
I/O: Output only
 Plant Scheduled Turbine Release
Type: SeriesSlot
Units: Flow
Description: Total scheduled turbine release for the reservoir (plant) at that timestep.
Information: This value is the sum over the columns of Unit Scheduled Turbine Release.
I/O: Output only
Method Details  
In Simulation, the Unit Power Table method will execute this method when the Unit Turbine Release is known. At this time, this method cannot be called if Unit Energy is specified (input or rules):
• Unit Scheduled Turbine Release[t,u] = Unit Turbine Release[t,u] - (Unit Flow Addition for Regulation[t,u] + Unit Flow Reduction For Regulation [t,u] )/2
• Unit Scheduled Mechanical Power[t,u] = Unit Power Table(head[t], Unit Scheduled Turbine Release[t,u])
• Unit Regulation Up[t.u] = Unit Power Table(head[t], Unit Scheduled Turbine Release[t,u] + Unit Flow Addition for Regulation[t,u] /2)
• Unit Regulation Down [t,u] = Unit Power Table(head[t], Unit Scheduled Turbine Release[t,u]-Unit Flow Reduction For Regulation [t,u]/2)
• Unit Regulation [t,u] = max(Unit Regulation Up[t.u] , Unit Regulation Down [t,u] )
• Unit Power[t,u] = Unit Scheduled Mechanical Power[t,u] + Unit Regulation Up[t.u]/2 - Unit Regulation Down [t,u]/2
• Calculate Unit Operating Cost[t,u] = timestep * Unit Operating Cost Per Regulation[u] * (Unit Regulation Up[t,u] + Unit Regulation Down[t,u])
• Compute plant level values as a sum of unit values
Revised: 11/11/2019