# pvlib.inverter.sandia¶

pvlib.inverter.sandia(v_dc, p_dc, inverter)[source]

Convert DC power and voltage to AC power using Sandia’s Grid-Connected PV Inverter model.

Parameters
• v_dc (numeric) – DC voltage input to the inverter. [V]

• p_dc (numeric) – DC power input to the inverter. [W]

• inverter (dict-like) – Defines parameters for the inverter model in 1.

Returns

power_ac (numeric) – AC power output. [W]

Notes

Determines the AC power output of an inverter given the DC voltage and DC power. Output AC power is bounded above by the parameter Paco, to represent inverter “clipping”. When power_ac would be less than parameter Pso (startup power required), then power_ac is set to -Pnt, representing self-consumption. power_ac is not adjusted for maximum power point tracking (MPPT) voltage windows or maximum current limits of the inverter.

Required model parameters are:

Column

Description

Paco

AC power rating of the inverter. [W]

Pdco

DC power input that results in Paco output at reference voltage Vdco. [W]

Vdco

DC voltage at which the AC power rating is achieved with Pdco power input. [V]

Pso

DC power required to start the inversion process, or self-consumption by inverter, strongly influences inverter efficiency at low power levels. [W]

C0

Parameter defining the curvature (parabolic) of the relationship between AC power and DC power at the reference operating condition. [1/W]

C1

Empirical coefficient allowing Pdco to vary linearly with DC voltage input. [1/V]

C2

Empirical coefficient allowing Pso to vary linearly with DC voltage input. [1/V]

C3

Empirical coefficient allowing C0 to vary linearly with DC voltage input. [1/V]

Pnt

AC power consumed by the inverter at night (night tare). [W]

A copy of the parameter database from the System Advisor Model (SAM) 2 is provided with pvlib and may be read using pvlib.pvsystem.retrieve_sam().

References

1

D. King, S. Gonzalez, G. Galbraith, W. Boyson, “Performance Model for Grid-Connected Photovoltaic Inverters”, SAND2007-5036, Sandia National Laboratories.

2

System Advisor Model web page. https://sam.nrel.gov.