Calculate the specified objective function
Parameters:
| Name |
Type |
Description |
Default |
i_figure_merit
|
int
|
the ID and sign of the figure of merit to evaluate.
A negative value indicates maximisation.
A positive value indicates minimisation.
* 1: Major radius
* 3: Neutron wall load
* 4: TF coil + PF coil power
* 5: Fusion gain
* 6: Cost of electricity
* 7: Direct/constructed/capital cost
* 8: Aspect ratio
* 9: Divertor heat load
* 10: Toroidal field on axis
* 11: Injected power
* 14: Pulse length
* 15: Plant availability
* 16: Major radius/burn time
* 17: Net electrical output
* 18: NULL, f(x) = 1
* 19: Major radius/burn time
|
required
|
data
|
DataStructure
|
data structure object for providing data to the
objective function
|
required
|
Raises:
| Type |
Description |
ProcessValueError
|
If i_figure_merit=15 not used with i_plant_availability=1
|
Source code in process/core/solver/objectives.py
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107 | def objective_function(i_figure_merit: int, data: DataStructure) -> float:
"""Calculate the specified objective function
Parameters
----------
i_figure_merit : int
the ID and sign of the figure of merit to evaluate.
A negative value indicates maximisation.
A positive value indicates minimisation.
* 1: Major radius
* 3: Neutron wall load
* 4: TF coil + PF coil power
* 5: Fusion gain
* 6: Cost of electricity
* 7: Direct/constructed/capital cost
* 8: Aspect ratio
* 9: Divertor heat load
* 10: Toroidal field on axis
* 11: Injected power
* 14: Pulse length
* 15: Plant availability
* 16: Major radius/burn time
* 17: Net electrical output
* 18: NULL, f(x) = 1
* 19: Major radius/burn time
data: DataStructure
data structure object for providing data to the
objective function
Raises
------
ProcessValueError
If i_figure_merit=15 not used with i_plant_availability=1
"""
try:
figure_of_merit = FiguresOfMerit(abs(i_figure_merit))
except ValueError as err:
raise ProcessValueError(
f"Invalid i_figure_merit value: {i_figure_merit}"
) from err
# -1 = maximise
# +1 = minimise
objective_sign = np.sign(i_figure_merit)
match FiguresOfMerit(figure_of_merit):
case FiguresOfMerit.MAJOR_RADIUS:
objective_metric = 0.2 * data.physics.rmajor
case FiguresOfMerit.NEUTRON_WALL_LOAD:
objective_metric = data.physics.pflux_fw_neutron_mw
case FiguresOfMerit.P_TF_PLUS_P_PF:
objective_metric = (data.tfcoil.tfcmw + 1e-3 * data.pf_power.srcktpm) / 10.0
case FiguresOfMerit.FUSION_GAIN_Q:
objective_metric = data.current_drive.big_q_plasma
case FiguresOfMerit.COST_OF_ELECTRICITY:
objective_metric = data.costs.coe / 100.0
case FiguresOfMerit.CAPITAL_COST:
objective_metric = (
data.costs.cdirt / 1.0e3
if data.costs.ireactor == 0
else data.costs.concost / 1.0e4
)
case FiguresOfMerit.ASPECT_RATIO:
objective_metric = data.physics.aspect
case FiguresOfMerit.DIVERTOR_HEAT_LOAD:
objective_metric = data.divertor.pflux_div_heat_load_mw
case FiguresOfMerit.TOROIDAL_FIELD:
objective_metric = data.physics.b_plasma_toroidal_on_axis
case FiguresOfMerit.TOTAL_INJECTED_POWER:
objective_metric = data.current_drive.p_hcd_injected_total_mw
case FiguresOfMerit.PULSE_LENGTH:
objective_metric = data.times.t_plant_pulse_burn / 2.0e4
case FiguresOfMerit.PLANT_AVAILABILITY_FACTOR:
if (
AvailabilityModel(data.costs.i_plant_availability)
== AvailabilityModel.USER_INPUT
):
raise ProcessValueError(
"i_figure_merit=15 requires `f_t_plant_available` to be calculated, "
"not user input"
)
objective_metric = data.costs.f_t_plant_available
case FiguresOfMerit.MIN_R0_MAX_TAU_BURN:
objective_metric = 0.95 * (data.physics.rmajor / 9.0) - 0.05 * (
data.times.t_plant_pulse_burn / 7200.0
)
case FiguresOfMerit.NET_ELECTRICAL_OUTPUT:
objective_metric = data.heat_transport.p_plant_electric_net_mw / 500.0
case FiguresOfMerit.NULL_FIGURE_OF_MERIT:
objective_metric = 1.0
case FiguresOfMerit.MAX_Q_MAX_T_PLANT_PULSE_BURN:
objective_metric = -0.5 * (data.current_drive.big_q_plasma / 20.0) - 0.5 * (
data.times.t_plant_pulse_burn / 7200.0
)
case _:
raise ProcessValueError(f"Unknown figure_of_merit: {figure_of_merit}")
return objective_sign * objective_metric
|