TWO BIPOLAR TRANSISTORS FORM A LOW COST SOLAR ARRAY EMULATOR
A. Garrigos, Josť A. Carrasco
ELECTRONIC DESIGN (2005)
Ed. Electronic Design ISSN:0013-4872 - Vol. FEB, 17 pp. 76-77
Polar-array systems are becoming a very important energy source. Today, they're being used in numerous applications where mains power isn't available or clean energy generation is preferred.
To determine the electrical and physical characteristics of the whole system, it's a good idea to use an experimental setup. It comes in handy when defining the solar-panel model and checking the power-conditioning system while its main parameters are varied.
The circuit presented here can be used as a very low-cost circuit for testing purposes. This eliminates the need for commercial solar emulators, which are expensive, not very common, and used only in specific areas.
The I-V characteristic of a solar panel can be mathematically modeled by Equation 1 as a current source with two independent terms. An ideal constant current appears in the low-voltage regime, and an exponential term dominates the high-voltage region, keeping the current in the panel low.