INSELpy

This module allows to execute INSEL models from Python, and can be used to write unit tests for INSEL blocks and models. The package is available at https://pypi.org/project/insel/

Single blocks

It can run single blocks, with the specified inputs, parameters and number of outputs:

>>> import insel
>>> insel.block('pi')
3.141593
>>> insel.block('sum', 2, 3)
5.0
>>> insel.block('do', parameters=[1, 10, 1])
[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]
>>> insel.block('gain', 2, 5, 7, parameters=[3], outputs=3)
[6.0, 15.0, 21.0]

INSEL templates

INSELpy can also run INSEL templates:

% Calculates a*b
s 1 MUL  3.1 2.1
s 2 CONST
p 2
           $a || 3$
s 3 CONST
p 3
           $b || 3$
s 4 SCREEN  1.1
p 4
    '*'

Templates will be searched inside the 'templates/' folder, relative to the current working directory.

Either in the REPL:

>>> insel.template('a_times_b', a=7, b=3)
21.0
>>> insel.template('photovoltaic/i_sc', pv_id='008823', temperature=25, irradiance=1000)
5.87388

or in complete scripts:

import insel

name = 'Roma'
lat = 41.8
lon = 12.58
timezone = 1

irradiances = insel.template('weather/get_irradiance_profile', latitude=lat, longitude=lon)
print(irradiances)
# => [71.0, 106.0, 158.0, 208.0, 251.0, 275.0, 286.0, 257.0, 196.0, 137.0, 84.0, 63.0]

print((insel.template('weather/average_irradiance_on_tilted_surface',
                      tilt=30,
                      azimuth=180,
                      irradiance_profile=irradiances,
                      latitude=lat,
                      longitude=lon,
                      timezone=timezone)))
# => 195.8578

Vseit models

Insel graphical models (Vseit) are valid templates. Constants defined by Define global constant block can be modified in Python.

If no value is specified in Python, the value defined in the block will be used by default.

>>> insel.template('constants/x_plus_y.vseit')
3.0
>>> insel.template('constants/x_plus_y.vseit', x=5)
7.0
>>> insel.template('constants/x_plus_y.vseit', x=5, y=5)
10.0

If the Vseit model contains a PLOT block, it will be deactivated by default. In order to launch gnuplot anyway, insel.template('model.vseit', gnuplot=True) can be used.

Gnuplot

insel.plot() works like insel.template() but also runs gnuplot on the result. The template must contain a PLOT block whose gnuplot script produces the desired output.

insel.plot('photovoltaic/iv_curve_text', pv_id='v410', u_max=45.0, ...)

INSEL models

It can also simply run complete models:

>>> insel.run('/usr/local/insel/examples/meteorology/sunae.vseit')
[]

PV modules

PhotovoltaicModuleModel runs the PVDET1 block to fit a single-diode model from datasheet specifications. A .bp file is written to output_folder (default: ./output/) and used by all subsequent simulation calls.

from insel import PhotovoltaicModuleModel

module = PhotovoltaicModuleModel(
    manufacturer_name="Trina",
    name="Vertex TSM 410",
    mpp=410, # [W]
    u_oc=41.6, # [V]
    i_sc=12.40, # [A]
    u_mpp=34.6, # [V]
    i_mpp=11.85, # [A]
    noct=43, # [°C]
    alpha_u_percent=-0.25, # [% / K]
    alpha_i_percent=0.04, # [% / K]
    rows=5, # [cells / row]
    columns=24, # [cells / column]
    height=1.754, # [m]
    width=1.096, # [m]
    eta=21.3, # [%]
    parallel=2, # [strings / module] 2 for half-cells, 1 otherwise
    # Optional:
    mass=21, # [kg]
    module_tolerance=3, # [%]
)

# datasheet vs. simulated comparison table; also writes an example .vseit file to output_folder
module.report()
# I(V,T) curves via gnuplot, displayed in terminal → plots/iv_curve_v410.txt
print(module.plot().read_text())   

Inverters

Inverter fits the three IVP block loss parameters that reproduce the specified $η_{max}$ and $η_{euro}$.

from insel import Inverter

inverter = Inverter(
    manufacturer_name="Fronius",
    name="Symo 10k",
    nominal_power=10000, # [W]
    eta_max=0.982, # [-] Max efficiency
    eta_euro=0.979, # [-] Euro efficiency
    # Optional:
    p_for_eta_max=0.40 # [-] At which efficiency is eta_max reached?
)

# datasheet vs. simulated comparison table; also writes an example .vseit file to output_folder
inverter.report()                   # specified vs. simulated efficiency comparison table
print(inverter.plot().read_text())  # η(DC) curve via gnuplot → plots/inverter_eta_curve_s10.txt