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Simulate solar panel characteristics for testing solar-powered devices.

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Import

There are two ways to control solar simulation: 
# Option 1: Net-based API (recommended)
from lager import Net, NetType

# Option 2: Dispatcher functions (for simple scripts)
from lager.solar.dispatcher import (
    set_to_solar_mode, stop_solar_mode, irradiance,
    mpp_current, mpp_voltage, resistance, temperature, voc
)
The lager.solar module’s __init__.py is empty. For dispatcher functions, import directly from lager.solar.dispatcher.

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Net API Methods

MethodDescription
connect_instrument()Connect and start solar simulation mode
disconnect_instrument()Disconnect and stop solar simulation
irradiance(value)Set or read irradiance (W/m²)
mpp_current()Read maximum power point current
mpp_voltage()Read maximum power point voltage
voc()Read open-circuit voltage
temperature()Read simulated cell temperature
resistance(value)Set or read panel resistance
Solar methods return string values from the instrument. Convert to float if needed for calculations.

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Method Reference

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Net.get(name, type=NetType.PowerSupply2Q)

Get a solar simulation net by name. 
from lager import Net, NetType

solar = Net.get('SOLAR', type=NetType.PowerSupply2Q)
Parameters:
ParameterTypeDescription
namestrName of the solar net
typeNetTypeMust be NetType.PowerSupply2Q
Returns: Solar simulation Net instance

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connect_instrument()

Connect to the instrument and start solar simulation mode. 
solar.connect_instrument()

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disconnect_instrument()

Disconnect from the instrument and stop solar simulation. 
solar.disconnect_instrument()

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irradiance(value=None)

Set or read the irradiance level. 
# Set irradiance
solar.irradiance(1000)  # Standard test condition (1000 W/m²)

# Read current irradiance
irr = solar.irradiance()
print(f"Irradiance: {irr}")  # Returns string
ParameterTypeDescription
valuefloat or NoneIrradiance in W/m² (0-1500). If None, reads current value.
Returns: str - Current irradiance value

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voc()

Read the open-circuit voltage. 
voc_str = solar.voc()
print(f"Voc: {voc_str}")
voc = float(voc_str)  # Convert to float for calculations
Returns: str - Voltage value

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mpp_voltage()

Read the maximum power point voltage. 
v_mpp = solar.mpp_voltage()
print(f"MPP voltage: {v_mpp}")
Returns: str - Voltage value

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mpp_current()

Read the maximum power point current. 
i_mpp = solar.mpp_current()
print(f"MPP current: {i_mpp}")
Returns: str - Current value

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resistance(value=None)

Set or read the dynamic panel resistance. 
# Set resistance
solar.resistance(5.0)

# Read resistance
r = solar.resistance()
print(f"Resistance: {r}")
ParameterTypeDescription
valuefloat or NoneResistance in ohms. If None, reads current value.
Returns: str - Resistance value

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temperature()

Read the simulated cell temperature. 
temp = solar.temperature()
print(f"Cell temp: {temp}")
Returns: str - Temperature value

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Examples

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Basic Solar Simulation

from lager import Net, NetType
import time

solar = Net.get('SOLAR_INPUT', type=NetType.PowerSupply2Q)

# Start simulation
solar.connect_instrument()

# Set standard test conditions (1000 W/m²)
solar.irradiance(1000)
time.sleep(1)

# Read panel characteristics (returns strings)
voc = solar.voc()
v_mpp = solar.mpp_voltage()
i_mpp = solar.mpp_current()

print(f"Voc: {voc}")
print(f"MPP: {v_mpp}V @ {i_mpp}A")

# Calculate max power (convert to float first)
v = float(v_mpp)
i = float(i_mpp)
print(f"Max Power: {v * i:.2f}W")

# Clean up
solar.disconnect_instrument()

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Test Multiple Irradiance Levels

from lager import Net, NetType
import time

solar = Net.get('SOLAR', type=NetType.PowerSupply2Q)
solar.connect_instrument()

conditions = [200, 500, 800, 1000, 1200]

for irr in conditions:
    solar.irradiance(irr)
    time.sleep(1)

    # Read and convert values
    voc = float(solar.voc())
    v_mpp = float(solar.mpp_voltage())
    i_mpp = float(solar.mpp_current())

    print(f"Irradiance: {irr} W/m²")
    print(f"  Voc: {voc:.2f}V")
    print(f"  MPP: {v_mpp:.2f}V @ {i_mpp:.3f}A")
    print(f"  Power: {v_mpp * i_mpp:.2f}W")
    print()

solar.disconnect_instrument()

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MPPT Tracking Test

from lager import Net, NetType
import time

solar = Net.get('SOLAR', type=NetType.PowerSupply2Q)
dut_current = Net.get('DUT_CURRENT', type=NetType.ADC)

solar.connect_instrument()
solar.irradiance(1000)

# Monitor MPPT tracking
for i in range(30):
    i_mpp = float(solar.mpp_current())
    actual = dut_current.input()

    efficiency = (actual / i_mpp) * 100 if i_mpp > 0 else 0
    print(f"Target: {i_mpp:.3f}A, Actual: {actual:.3f}A, Eff: {efficiency:.1f}%")
    time.sleep(1)

solar.disconnect_instrument()

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Supported Hardware

ManufacturerModelFeatures
EAPSI/EL seriesTwo-quadrant, PV simulation
EAPSB 10060-60Bidirectional
EAPSB 10080-60Bidirectional

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Dispatcher Functions

For simple scripts, you can use dispatcher functions that take net names directly:

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Mode Control

from lager.solar.dispatcher import set_to_solar_mode, stop_solar_mode

# Start solar simulation mode
set_to_solar_mode('SOLAR')

# Stop solar simulation
stop_solar_mode('SOLAR')

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Irradiance Control

from lager.solar.dispatcher import irradiance

# Set irradiance to 1000 W/m² (Standard Test Conditions)
irradiance('SOLAR', 1000)

# Read current irradiance setting (value=None)
irradiance('SOLAR')

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Read Measurements

from lager.solar.dispatcher import mpp_current, mpp_voltage, voc, temperature

# Read maximum power point values (returns strings)
i_mpp = mpp_current('SOLAR')
v_mpp = mpp_voltage('SOLAR')
v_oc = voc('SOLAR')
temp = temperature('SOLAR')

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Panel Resistance

from lager.solar.dispatcher import resistance

# Set panel resistance
resistance('SOLAR', 5.0)

# Read panel resistance (value=None)
resistance('SOLAR')

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Dispatcher Functions Reference

FunctionDescription
set_to_solar_mode(netname)Initialize solar simulation mode
stop_solar_mode(netname)Stop solar simulation
irradiance(netname, value=None)Set/read irradiance (W/m²)
mpp_current(netname)Read MPP current
mpp_voltage(netname)Read MPP voltage
voc(netname)Read open-circuit voltage
temperature(netname)Read cell temperature
resistance(netname, value=None)Set/read panel resistance

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Dispatcher vs Net API

# Dispatcher functions (simpler, uses net name directly)
from lager.solar.dispatcher import set_to_solar_mode, irradiance, mpp_voltage, mpp_current

set_to_solar_mode('SOLAR')
irradiance('SOLAR', 1000)
v = mpp_voltage('SOLAR')
i = mpp_current('SOLAR')
print(f"MPP: {v}V @ {i}A")

# Net API (object-oriented)
from lager import Net, NetType

solar = Net.get('SOLAR', type=NetType.PowerSupply2Q)
solar.connect_instrument()
solar.irradiance(1000)
v = solar.mpp_voltage()
i = solar.mpp_current()
print(f"MPP: {v}V @ {i}A")
solar.disconnect_instrument()

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Notes

  • Solar simulation requires bidirectional (two-quadrant) power supplies
  • Standard Test Conditions (STC): 1000 W/m², 25°C, AM1.5
  • The I-V curve is automatically generated based on irradiance
  • Call connect_instrument() before using solar-specific methods
  • Always call disconnect_instrument() when finished
  • Return values are strings - convert to float for calculations
  • Dispatcher functions use net names directly for simpler scripts