def test_batterystateful_model_change_chemistry():
model = battstfl.default("leadacid")
original_capacity = model.ParamsPack.nominal_energy
BatteryTools.battery_model_change_chemistry(model, 'nmcgraphite')
params_new = battstfl.default('nmcgraphite').export()
cell_params = params_new['ParamsCell']
pack_params = params_new['ParamsPack']
assert (model.value('nominal_energy') == pytest.approx(
original_capacity, 0.1))
assert (model.ParamsCell.Vnom_default == cell_params['Vnom_default'])
assert (model.ParamsPack.Cp == pack_params['Cp'])
def chem_batterystateful(model: BattStfl.BatteryStateful, chem):
"""
Helper function for battery_model_change_chemistry
"""
if type(model) != BattStfl.BatteryStateful:
raise TypeError
chem = chem.lower()
if chem != 'LeadAcid' and chem != 'lfpgraphite' and chem != 'nmcgraphite':
raise NotImplementedError
if chem == 'leadacid':
model.ParamsCell.chem = 0
else:
model.ParamsCell.chem = 1
original_capacity = model.ParamsPack.nominal_energy
original_voltage = model.ParamsPack.nominal_voltage
params_dict = BattStfl.default(chem).export()
for group in ('ParamsCell', 'ParamsPack'):
for k, v in params_dict[group].items():
model.value(k, v)
battery_model_sizing(model, -1, original_capacity, original_voltage)
def __init__(self,
site: SiteInfo,
battery_config: dict,
chemistry: str = 'lfpgraphite',
system_voltage_volts: float = 500):
"""
Battery Storage class based on PySAM's BatteryStateful Model
:param site: Power source site information (SiteInfo object)
:param battery_config: Battery configuration with the following keys:
#. ``system_capacity_kwh``: float, Battery energy capacity [kWh]
#. ``system_capacity_kw``: float, Battery rated power capacity [kW]
:param chemistry: Battery storage chemistry, options include:
#. ``LFPGraphite``: Lithium Iron Phosphate (Lithium Ion)
#. ``LMOLTO``: LMO/Lithium Titanate (Lithium Ion)
#. ``LeadAcid``: Lead Acid
#. ``NMCGraphite``: Nickel Manganese Cobalt Oxide (Lithium Ion)
:param system_voltage_volts: Battery system voltage [VDC]
"""
for key in ('system_capacity_kwh', 'system_capacity_kw'):
if key not in battery_config.keys():
raise ValueError
system_model = BatteryModel.default(chemistry)
financial_model = Singleowner.from_existing(system_model, "StandaloneBatterySingleOwner")
super().__init__("Battery", site, system_model, financial_model)
self.Outputs = BatteryOutputs(n_timesteps=site.n_timesteps)
self.system_capacity_kw: float = battery_config['system_capacity_kw']
self.chemistry = chemistry
BatteryTools.battery_model_sizing(self._system_model,
battery_config['system_capacity_kw'],
battery_config['system_capacity_kwh'],
system_voltage_volts,
module_specs=Battery.module_specs)
self._system_model.ParamsPack.h = 20
self._system_model.ParamsPack.Cp = 900
self._system_model.ParamsCell.resistance = 0.001
self._system_model.ParamsCell.C_rate = battery_config['system_capacity_kw'] / battery_config['system_capacity_kwh']
# Minimum set of parameters to set to get statefulBattery to work
self._system_model.value("control_mode", 0.0)
self._system_model.value("input_current", 0.0)
self._system_model.value("dt_hr", 1.0)
self._system_model.value("minimum_SOC", 10.0)
self._system_model.value("maximum_SOC", 90.0)
self._system_model.value("initial_SOC", 10.0)
self._dispatch = None
logger.info("Initialized battery with parameters and state {}".format(self._system_model.export()))
def test_battery_model_change_chemistry():
model = batt.default("GenericBatterySingleOwner")
original_capacity = model.value('batt_computed_bank_capacity')
original_power = model.BatterySystem.batt_power_discharge_max_kwac
BatteryTools.battery_model_change_chemistry(model, 'leadacid')
params_new = battstfl.default('leadacid').export()
cell_params = params_new['ParamsCell']
pack_params = params_new['ParamsPack']
assert (model.value('batt_computed_bank_capacity') == pytest.approx(
original_capacity, 0.1))
assert (model.value('batt_power_discharge_max_kwac') == pytest.approx(
original_power, 0.1))
assert (model.BatteryCell.batt_chem == cell_params['chem'])
assert (model.BatteryCell.batt_calendar_choice ==
cell_params['calendar_choice'])
assert (model.BatteryCell.batt_Vnom_default == cell_params['Vnom_default'])
assert (
model.BatteryCell.LeadAcid_q10_computed == cell_params['leadacid_q10'])
assert (model.BatteryCell.batt_Cp == pack_params['Cp'])
BatteryTools.battery_model_change_chemistry(model, 'nmcgraphite')
params_new = battstfl.default('nmcgraphite').export()
cell_params = params_new['ParamsCell']
pack_params = params_new['ParamsPack']
assert (model.value('batt_computed_bank_capacity') == pytest.approx(
original_capacity, 0.1))
assert (model.value('batt_power_discharge_max_kwac') == pytest.approx(
original_power, 0.1))
assert (model.BatteryCell.batt_C_rate == cell_params['C_rate'])
assert (model.BatteryCell.batt_calendar_choice ==
cell_params['calendar_choice'])
assert (model.BatteryCell.batt_Vexp == cell_params['Vexp'])
assert (model.BatteryCell.batt_Cp == pack_params['Cp'])
def test_stateful():
b = bt.default("NMCGraphite")
b.Controls.control_mode = 1
b.Controls.dt_hr = 1
b.ParamsCell.minimum_SOC = 10
b.ParamsCell.maximum_SOC = 90
b.ParamsCell.initial_SOC = 50
b.Controls.input_power = 0
b.setup()
assert (b.StatePack.SOC == approx(50))
b.Controls.input_power = 0.5
b.execute(0)
assert (b.StatePack.SOC == approx(44.811, 1e-2))
def test_stateful_lmolto():
b = bt.default("LMOLTO")
b.Controls.control_mode = 1
b.Controls.dt_hr = 1
b.ParamsCell.minimum_SOC = 10
b.ParamsCell.maximum_SOC = 90
b.ParamsCell.initial_SOC = 50
b.Controls.input_power = 0
b.setup()
assert (b.StatePack.SOC == approx(50))
b.Controls.input_power = 0.5
b.execute(0)
assert (b.StatePack.SOC == approx(45.216, 1e-2))
def chem_battery(model: Batt.Battery, chem):
"""
Helper function for battery_model_change_chemistry
"""
if type(model) != Batt.Battery:
raise TypeError
chem = chem.lower()
if chem != 'leadacid' and chem != 'lfpgraphite' and chem != 'nmcgraphite':
raise NotImplementedError
if chem == 'leadacid':
model.BatteryCell.batt_chem = 0
else:
model.BatteryCell.batt_chem = 1
original_capacity = model.value('batt_computed_bank_capacity')
original_voltage = model.BatteryCell.batt_Vnom_default * model.BatterySystem.batt_computed_series
if model.BatterySystem.batt_ac_or_dc:
original_power = model.BatterySystem.batt_power_discharge_max_kwac
else:
original_power = model.BatterySystem.batt_power_discharge_max_kwdc
params_dict = BattStfl.default(chem).export()
for group in ('ParamsCell', 'ParamsPack'):
for k, v in params_dict[group].items():
if k == 'nominal_voltage' or k == "T_room_init":
continue
elif k == 'cycling_matrix':
k = 'batt_lifetime_matrix'
elif 'leadacid' in k:
k = 'LeadAcid' + k[8:]
if 'tn' not in k:
k += '_computed'
elif k == 'h':
k = 'batt_h_to_ambient'
elif k == 'nominal_energy':
k = 'batt_computed_bank_capacity'
elif k == 'cap_vs_temp':
pass
else:
k = 'batt_' + k
model.value(k, v)
battery_model_sizing(model, original_power, original_capacity,
original_voltage)