Source code for RCAIDE.Library.Methods.Powertrain.Sources.Batteries.Common.compute_module_properties
# RCAIDE/Methods/Powertrain/Sources/Batteries/Common/compute_module_properties.py
#
#
# Created: Jul 2023, M. Clarke
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# IMPORT
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from RCAIDE.Framework.Core import Units
import numpy as np
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# METHOD
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[docs]
def compute_module_properties(battery_module):
"""
Calculates module level properties of battery module using cell properties and module configuration.
Parameters
----------
battery_module : BatteryModule
The battery module with the following attributes:
- cell.nominal_capacity : float
Nominal capacity of a single cell [Ah]
- cell.maximum_voltage : float
Maximum voltage of a single cell [V]
- cell.mass : float
Mass of a single cell [kg]
- electrical_configuration.series : int
Number of cells in series
- electrical_configuration.parallel : int
Number of cells in parallel
- geometrtic_configuration : GeometricConfiguration
Object containing geometric layout information
- volume_packaging_factor : float
Factor accounting for additional volume due to packaging
- orientation_euler_angles : numpy.ndarray
Euler angles for module orientation [rad]
- BMS_additional_weight_factor : float
Factor accounting for battery management system weight
Returns
-------
None
This function modifies the battery_module object in-place, setting the following attributes:
- length : float
Length of the battery module [m]
- width : float
Width of the battery module [m]
- height : float
Height of the battery module [m]
- mass_properties.mass : float
Total mass of the battery module [kg]
- specific_energy : float
Specific energy of the battery module [Wh/kg]
- maximum_energy : float
Maximum energy capacity of the battery module [J]
- specific_power : float
Specific power of the battery module [W/kg]
- maximum_power : float
Maximum power output of the battery module [W]
- maximum_voltage : float
Maximum voltage of the battery module [V]
- initial_maximum_energy : float
Initial maximum energy capacity [J]
- nominal_capacity : float
Nominal capacity of the battery module [Ah]
- voltage : float
Voltage of the battery module [V]
Notes
-----
This function calculates the physical and electrical properties of a battery module
based on the properties of its constituent cells and the module configuration.
The physical dimensions are calculated based on the geometric layout of cells,
including spacing between cells and a volume packaging factor. The module orientation
can be adjusted using Euler angles.
The electrical properties are calculated based on the series-parallel configuration
of cells, with series connections increasing voltage and parallel connections
increasing capacity.
**Major Assumptions**
* Total battery module pack mass can be modeled with a build-up factor for battery module casing,
internal wires, thermal management system and battery module management system.
References
----------
[1] Chin, J. C., Schnulo, S. L., Miller, T. B., Prokopius, K., and Gray, J., "Battery Performance Modeling on Maxwell X-57", AIAA Scitech, San Diego, CA, 2019. URL http://openmdao.org/pubs/chin_battery_performance_x57_2019.pdf.
"""
series_e = battery_module.electrical_configuration.series
parallel_e = battery_module.electrical_configuration.parallel
normal_count = battery_module.geometrtic_configuration.normal_count
parallel_count = battery_module.geometrtic_configuration.parallel_count
stacking_rows = battery_module.geometrtic_configuration.stacking_rows
if int(parallel_e*series_e) != int(normal_count*parallel_count):
pass #raise Exception('Number of cells in gemetric layout not equal to number of cells in electric circuit configuration ')
normal_spacing = battery_module.geometrtic_configuration.normal_spacing
parallel_spacing = battery_module.geometrtic_configuration.parallel_spacing
volume_factor = battery_module.volume_packaging_factor
cell_diameter = battery_module.cell.diameter
cell_height = battery_module.cell.height
euler_angles = battery_module.orientation_euler_angles
weight_factor = battery_module.BMS_additional_weight_factor
x1 = normal_count * (cell_diameter + normal_spacing) * volume_factor # distance in the module-level normal direction
x2 = parallel_count * (cell_diameter + parallel_spacing) * volume_factor # distance in the module-level parallel direction
x3 = cell_height * volume_factor # distance in the module-level height direction
length = x1 / stacking_rows
width = x2
height = x3 *stacking_rows
if euler_angles[0] == (np.pi / 2):
x1prime = x2
x2prime = -x1
x3prime = x3
if euler_angles[1] == (np.pi / 2):
x1primeprime = -x3prime
x2primeprime = x2prime
x3primeprime = x1prime
if euler_angles[2] == (np.pi / 2):
length = x1primeprime
width = x3primeprime
height = -x2primeprime
# store length, width and height
battery_module.length = length
battery_module.width = width
battery_module.height = height
amp_hour_rating = battery_module.cell.nominal_capacity
total_battery_assemply_mass = battery_module.cell.mass * series_e * parallel_e
battery_module.mass_properties.mass = total_battery_assemply_mass*weight_factor
battery_module.specific_energy = (amp_hour_rating*battery_module.cell.maximum_voltage)/battery_module.cell.mass * Units.Wh/Units.kg
battery_module.maximum_energy = total_battery_assemply_mass*battery_module.specific_energy
battery_module.specific_power = battery_module.specific_energy/battery_module.cell.nominal_capacity
battery_module.maximum_power = battery_module.specific_power*battery_module.mass_properties.mass
battery_module.maximum_voltage = battery_module.cell.maximum_voltage * series_e
battery_module.initial_maximum_energy = battery_module.maximum_energy
battery_module.nominal_capacity = battery_module.cell.nominal_capacity* parallel_e
battery_module.voltage = battery_module.maximum_voltage
