def test_liion_dc_connected_dc_sizing():
model = batt.default("GenericBatteryCommercial")
model.BatteryCell.batt_chem = 1
model.Inverter.inverter_model = 0
model.Inverter.inv_snl_eff_cec = 50
model.BatterySystem.batt_ac_or_dc = 0
BatteryTools.battery_model_sizing(model, 100, 400, 500)
assert (model.BatterySystem.batt_computed_bank_capacity == pytest.approx(
400, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwdc == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_power_charge_max_kwdc == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwac == pytest.approx(
49, 1))
assert (model.BatterySystem.batt_power_charge_max_kwac == pytest.approx(
204, 1))
assert (model.BatterySystem.batt_current_discharge_max == pytest.approx(
200, 1))
assert (model.BatterySystem.batt_current_charge_max == pytest.approx(
200, 1))
model.Inverter.inv_snl_eff_cec = 100
model.BatterySystem.batt_ac_or_dc = 0
BatteryTools.battery_model_sizing(model, 100, 400, 500)
assert (model.BatterySystem.batt_computed_bank_capacity == pytest.approx(
400, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwdc == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_power_charge_max_kwdc == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwac == pytest.approx(
98, 1))
assert (model.BatterySystem.batt_power_charge_max_kwac == pytest.approx(
102, 1))
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_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 test_leadacid():
model = batt.default("GenericBatteryCommercial")
model.BatteryCell.batt_chem = 0
assert (model.BatterySystem.batt_computed_bank_capacity != pytest.approx(
100, .5))
assert (model.BatterySystem.batt_power_charge_max_kwdc != pytest.approx(
50, 0.5))
BatteryTools.battery_model_sizing(model, 100, 400, 500)
assert (model.BatterySystem.batt_computed_strings == 261)
assert (model.BatterySystem.batt_computed_series == 139)
assert (model.BatterySystem.batt_computed_bank_capacity == pytest.approx(
417, 1))
assert (model.BatterySystem.batt_power_charge_max_kwdc == pytest.approx(
96.29, 1))
def system_capacity_voltage(self, capacity_voltage: tuple):
size_kwh = capacity_voltage[0]
voltage_volts = capacity_voltage[1]
# sizing function may run into future issues if size_kwh == 0 is allowed
if size_kwh == 0:
size_kwh = 1e-7
BatteryTools.battery_model_sizing(self._system_model,
0.,
size_kwh,
voltage_volts,
module_specs=Battery.module_specs)
logger.info("Battery set system_capacity to {} kWh".format(size_kwh))
logger.info("Battery set system_voltage to {} volts".format(voltage_volts))
def test_liion_ac_connected_ac_sizing():
model = batt.default("GenericBatteryCommercial")
model.BatteryCell.batt_chem = 1
model.BatterySystem.batt_ac_or_dc = 1 # ac
BatteryTools.battery_model_sizing(model, 100, 400, 500)
assert (model.BatterySystem.batt_computed_bank_capacity == pytest.approx(
417, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwdc == pytest.approx(
104, 1))
assert (model.BatterySystem.batt_power_charge_max_kwdc == pytest.approx(
96, 1))
assert (model.BatterySystem.batt_power_discharge_max_kwac == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_power_charge_max_kwac == pytest.approx(
100, 1))
assert (model.BatterySystem.batt_current_discharge_max == pytest.approx(
208, 1))
assert (model.BatterySystem.batt_current_charge_max == pytest.approx(
192, 1))
def test_calculate_thermal_params():
input_dict = {
'mass': 20272.2,
'surface_area': 23.9614,
'original_capacity': 4000.323,
'desired_capacity': 2000
}
output = BatteryTools.calculate_thermal_params(input_dict)
assert (output['mass'] == pytest.approx(10135.28))
assert (output['surface_area'] == pytest.approx(15.09392))
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 _size_battery(self):
if self.storage:
# --- Force duration to be 0, 2, 4 ---
desired_duration = self.system_config['BatteryTools'][
'desired_capacity']
if desired_duration < 1:
self.battery_duration = 0
self.storage = False
elif desired_duration < 2:
self.battery_duration = 2
elif desired_duration <= 4:
self.battery_duration = 4
self.system_config['BatteryTools'][
'desired_capacity'] = self.battery_duration * self.system_config[
'BatteryTools'][
'desired_power'] #convert capacity expressed in hours to kWh
self.battery_params = self.battery_sizing_config = bt.battery_model_sizing(
model=self.battery, **self.system_config['BatteryTools'])
else:
self.battery_params = None
def chemistry(self, battery_chemistry: str):
BatteryTools.battery_model_change_chemistry(self._system_model, battery_chemistry)
self._chemistry = battery_chemistry
logger.info("Battery chemistry set to {}".format(battery_chemistry))
