def generate_random_GenericWindTurbinePowerCurveVT(D=None):
"""
Generate a random turbine and power curve using the GenericWindTurbinePowerCurveVT class
Parameters
----------
D float, default=random, (optional)
The wind turbine rotor diameter
Returns
-------
wt_desc GenericWindTurbinePowerCurveVT
A random wind turbine power curve and c_t curve variable tree
"""
if not D:
D = 200 * random()
wt_desc = GenericWindTurbinePowerCurveVT()
wt_desc.rotor_diameter = D
wt_desc.hub_height = D * (0.5 + random())
wt_desc.cut_in_wind_speed = 2. + 4. * random()
wt_desc.cut_out_wind_speed = 20. + 10. * random()
rho = 1.225
rated_wind_speed = 8. + 4. * random()
max_a = 0.333 * random()
max_cp = 4 * max_a * (1 - max_a)**2.
max_ct = 4 * max_a * (1 - max_a)
A = 0.25 * pi * D**2. # Rotor area
ideal_power = lambda ws: 0.5 * rho * A * max_cp * ws**3.
real_power = lambda ws: ideal_power(
ws) if ws < rated_wind_speed else ideal_power(rated_wind_speed)
#a_ct = -sqrt(-c_t + 1)/2 + 1/2
ct_from_cp = lambda cp: min(0.89, cp * 2.)
cp_from_power = lambda power, ws: power / (0.5 * rho * A * ws**3.)
ct_from_power = lambda pws: ct_from_cp(cp_from_power(pws[0], pws[1]))
N = 3 + int(random() * 100)
ws = linspace(wt_desc.cut_in_wind_speed, wt_desc.cut_out_wind_speed, N)
wt_desc.power_curve = vstack([ws, map(real_power, ws)]).T
wt_desc.c_t_curve = vstack(
[ws, map(ct_from_power, zip(wt_desc.power_curve[:, 1], ws))]).T
wt_desc.power_rating = ideal_power(rated_wind_speed)
wt_desc.rated_wind_speed = rated_wind_speed
wt_desc.air_density = rho
wt_desc.test_consistency()
return wt_desc
def generate_random_GenericWindTurbinePowerCurveVT(D=None):
"""
Generate a random turbine and power curve using the GenericWindTurbinePowerCurveVT class
Parameters
----------
D float, default=random, (optional)
The wind turbine rotor diameter
Returns
-------
wt_desc GenericWindTurbinePowerCurveVT
A random wind turbine power curve and c_t curve variable tree
"""
if not D:
D = 200*random()
wt_desc = GenericWindTurbinePowerCurveVT()
wt_desc.rotor_diameter = D
wt_desc.hub_height = D * (0.5 + random())
wt_desc.cut_in_wind_speed = 2. + 4. * random()
wt_desc.cut_out_wind_speed = 20. + 10. * random()
rho = 1.225
rated_wind_speed = 8. + 4. * random()
max_a = 0.333 * random()
max_cp = 4 * max_a * (1 - max_a)**2.
max_ct = 4 * max_a * (1 - max_a)
A = 0.25 * pi * D**2. # Rotor area
ideal_power = lambda ws: 0.5 * rho * A * max_cp * ws **3.
real_power = lambda ws: ideal_power(ws) if ws < rated_wind_speed else ideal_power(rated_wind_speed)
#a_ct = -sqrt(-c_t + 1)/2 + 1/2
ct_from_cp = lambda cp: min(0.89, cp * 2.)
cp_from_power = lambda power, ws: power/(0.5 * rho * A * ws**3.)
ct_from_power = lambda pws: ct_from_cp(cp_from_power(pws[0], pws[1]))
N = 3+int(random() * 100)
ws = linspace(wt_desc.cut_in_wind_speed, wt_desc.cut_out_wind_speed, N)
wt_desc.power_curve = vstack([ws, map(real_power, ws)]).T
wt_desc.c_t_curve = vstack([ws, map(ct_from_power, zip(wt_desc.power_curve[:,1],ws))]).T
wt_desc.power_rating = ideal_power(rated_wind_speed)
wt_desc.rated_wind_speed = rated_wind_speed
wt_desc.air_density = rho
wt_desc.test_consistency()
return wt_desc