One basic equivalent circuit model in common use is the single diode model, which is derived from physical principles (e.g., Gray, 2011) and represented by the following circuit for a single solar cell: The governing equation for this equivalent circuit is formulated using Kirchoff’s current law for current $$I$$: $$I=I_L – I_D – I_ {sh}$$
These models are invaluable for understanding fundamental device physics, explaining specific phenomena, and aiding in the design of more efficient devices. The equivalent circuit of a solar cell consists of an ideal current generator in parallel with a diode in reverse bias, both of which are connected to a load.
Conventional equivalent circuit model The most common equivalent circuit-based model used in the literature to characterize the PV cells is the ODEC model, illustrated previously in Fig. 1 (a). Also, it is often considered a simple and accurate model .
An equivalent circuit model presents a theoretical circuit diagram, which captures the electrical characteristics of a device. It is important to note the components illustrated in the model are not physically present in the devices themselves.
Moreover, in most circuit simulators, parameters of the PV source electrical circuit model refer to the circuit elements (, , and of the diode). where only two parameters (Iph and Id) are considered as function of the solar irradiance and cell temperature by using two controlled current sources.
The seven-parameter model is based on the one-diode equiva-lent circuit model of a PV cell and is conceptually similar to the five-parameter model. This model is an extension of the six-parameter model, which is currently used by the California En-ergy Commission CEC and is one of the models in the Solar Advisory Model SAM developed by NREL.