import numpy as np
from linerate.equations import (
cigre601,
convective_cooling,
dimensionless,
math,
solar_angles,
solar_heating,
)
from linerate.models.thermal_model import ThermalModel, _copy_method_docstring
from linerate.types import BaseWeather, Span, Weather, WeatherWithSolarRadiation
from linerate.units import (
Ampere,
Celsius,
Date,
JoulePerKilogramPerKelvin,
OhmPerMeter,
Unitless,
WattPerMeter,
)
class BaseCigre601(ThermalModel):
DEFAULT_MAX_REYNOLDS_NUMBER = 4000.0 # Max value of the angle correction in CIGRE601
def __init__(
self,
span: Span,
weather: BaseWeather,
time: Date,
max_reynolds_number: Unitless = DEFAULT_MAX_REYNOLDS_NUMBER,
):
super().__init__(span, weather)
self.time = time
self.max_reynolds_number = max_reynolds_number
@_copy_method_docstring(ThermalModel)
def compute_resistance(self, conductor_temperature: Celsius, current: Ampere) -> OhmPerMeter:
return super().compute_resistance(
conductor_temperature=conductor_temperature, current=current
)
@_copy_method_docstring(ThermalModel)
def compute_joule_heating(
self, conductor_temperature: Celsius, current: Ampere
) -> WattPerMeter:
return super().compute_joule_heating(
conductor_temperature=conductor_temperature, current=current
)
@_copy_method_docstring(ThermalModel)
def compute_convective_cooling(
self,
conductor_temperature: Celsius,
) -> WattPerMeter:
D = self.span.conductor.conductor_diameter
d = self.span.conductor.outer_layer_strand_diameter
y = self.span.conductor_altitude
beta = self.span.inclination
V = self.weather.wind_speed
T_a = self.weather.air_temperature
T_c = conductor_temperature
T_f = 0.5 * (T_c + T_a)
# Compute physical quantities
lambda_f = cigre601.convective_cooling.compute_thermal_conductivity_of_air(T_f)
mu_f = cigre601.convective_cooling.compute_dynamic_viscosity_of_air(T_f)
gamma_f = cigre601.convective_cooling.compute_air_density(T_f, y)
nu_f = cigre601.convective_cooling.compute_kinematic_viscosity_of_air(mu_f, gamma_f)
c_f: JoulePerKilogramPerKelvin = 1005
delta = math.compute_angle_of_attack(
self.weather.wind_direction, self.span.conductor_azimuth
)
# Compute unitless quantities
Re = np.minimum(
dimensionless.compute_reynolds_number(V, D, nu_f),
self.max_reynolds_number,
)
Gr = dimensionless.compute_grashof_number(D, T_c, T_a, nu_f)
Pr = dimensionless.compute_prandtl_number(lambda_f, mu_f, c_f)
Rs = dimensionless.compute_conductor_roughness(D, d)
# Compute nusselt numbers
Nu_90 = cigre601.convective_cooling.compute_perpendicular_flow_nusseltnumber(
reynolds_number=Re, conductor_roughness=Rs
)
Nu_delta = cigre601.convective_cooling.correct_wind_direction_effect_on_nusselt_number(
Nu_90, delta, Rs
)
Nu_0 = cigre601.convective_cooling.compute_horizontal_natural_nusselt_number(Gr, Pr)
Nu_beta = cigre601.convective_cooling.correct_natural_nusselt_number_inclination(
Nu_0, beta, Rs
)
Nu = cigre601.convective_cooling.compute_nusselt_number(
forced_convection_nusselt_number=Nu_delta, natural_nusselt_number=Nu_beta
)
return convective_cooling.compute_convective_cooling(
surface_temperature=conductor_temperature,
air_temperature=self.weather.air_temperature,
nusselt_number=Nu,
thermal_conductivity_of_air=lambda_f,
)
@_copy_method_docstring(ThermalModel)
def compute_radiative_cooling(
self,
conductor_temperature: Celsius,
) -> WattPerMeter:
return super().compute_radiative_cooling(
conductor_temperature=conductor_temperature,
)
def compute_temperature_gradient(
self, conductor_temperature: Celsius, current: Ampere
) -> Celsius:
r"""Estimate the difference between the core temperature and the surface temperature.
Parameters
----------
conductor_temperature:
:math:`T_\text{av}~\left[^\circ\text{C}\right]`. The average conductor temperature.
current:
:math:`I~\left[\text{A}\right]`. The current.
Returns
-------
Union[float, float64, ndarray[Any, dtype[float64]]]
:math:`T_c - T_s~\left[^\circ \text{C}\right]`. The difference between the core and the
surface temperature of the conductor.
"""
n = self.span.num_conductors
T_c = conductor_temperature
I = current / n # noqa
R = self.compute_resistance(conductor_temperature=T_c, current=I)
return cigre601.convective_cooling.compute_temperature_gradient(
total_heat_gain=I * R,
conductor_thermal_conductivity=self.span.conductor.thermal_conductivity, # type: ignore # noqa
core_diameter=self.span.conductor.core_diameter,
conductor_diameter=self.span.conductor.conductor_diameter,
)
[docs]
class Cigre601(BaseCigre601):
"""Extension of the BaseCigre601 model that uses the solar radiation parametrisation in CIGRE601."""
def __init__(
self,
span: Span,
weather: Weather,
time: Date,
max_reynolds_number: Unitless = BaseCigre601.DEFAULT_MAX_REYNOLDS_NUMBER,
):
self.span = span
self.weather = weather
self.time = time
self.max_reynolds_number = max_reynolds_number
[docs]
@_copy_method_docstring(ThermalModel)
def compute_solar_heating(self) -> WattPerMeter:
alpha_s = self.span.conductor.solar_absorptivity
F = self.weather.ground_albedo
y = self.span.conductor_altitude
N_s = self.weather.clearness_ratio
D = self.span.conductor.conductor_diameter
sin_H_s = solar_angles.compute_sin_solar_altitude_for_span(self.span, self.time)
sin_eta = solar_angles.compute_sin_solar_effective_incidence_angle_for_span(
self.span, self.time, sin_H_s
)
I_B = cigre601.solar_heating.compute_direct_solar_radiation(sin_H_s, N_s, y)
I_d = cigre601.solar_heating.compute_diffuse_sky_radiation(I_B, sin_H_s)
I_T = cigre601.solar_heating.compute_global_radiation_intensity(
I_B, I_d, F, sin_eta, sin_H_s
)
return solar_heating.compute_solar_heating(
alpha_s,
I_T,
D,
)
class Cigre601WithSolarRadiation(BaseCigre601):
"""Extension of the BaseCigre601 model that accepts external solar radiation data for direct and diffuse solar
radiation."""
def __init__(
self,
span: Span,
weather: WeatherWithSolarRadiation,
time: Date,
max_reynolds_number: Unitless = BaseCigre601.DEFAULT_MAX_REYNOLDS_NUMBER,
):
self.span = span
self.weather = weather
self.time = time
self.max_reynolds_number = max_reynolds_number
def compute_solar_heating(self) -> WattPerMeter:
alpha_s = self.span.conductor.solar_absorptivity
F = self.weather.ground_albedo
D = self.span.conductor.conductor_diameter
I_B = self.weather.direct_radiation_intensity
I_d = self.weather.diffuse_radiation_intensity
sin_H_s = solar_angles.compute_sin_solar_altitude_for_span(self.span, self.time)
sin_eta = solar_angles.compute_sin_solar_effective_incidence_angle_for_span(
self.span, self.time, sin_H_s
)
I_T = cigre601.solar_heating.compute_global_radiation_intensity(
I_B, I_d, F, sin_eta, sin_H_s
)
return solar_heating.compute_solar_heating(
alpha_s,
I_T,
D,
)