The Measurement and SPICE Modelling of Schottky Barrier Diodes Appropriate for Use as Bypass Diodes within Photovoltaic Modules

Abstract

The modelling of surges within PV (photovoltaic) installations has been the subject of much research in recent years. However, accurate simulations cannot be performed unless each and every component within a PV installation is modelled in sufficient detail. The bypass diodes within a PV module are frequently omitted from such simulations. When included, they are often represented by oversimplified models. This article addresses this need by presenting SPICE (Simulation Program with Integrated Circuit Emphasis) models for three Schottky diodes, chosen due to their suitability for use as bypass diodes. These models are the combination of DC (direct current) large-signal and AC (alternating current) small-signal sub-models, which are integrated such that the resulting full circuital models allow for accurate simulations involving large-signal transient stimuli. Two types of experimental setups, one incorporating a DC current–voltage curve sweep, and the other involving VNA-based (vector network analyser) AC small-signal impedance measurements, allow for the acquisition of the necessary model parameters at multiple operating points. The AC small-signal measurements cover a wide bandwidth of 100 Hz to 50 MHz. Multiple configurations of the measurement setups are employed in order to achieve the required dynamic range and sensitivity.