Overcoming the problems in determination of solar cell series resistance and diode factor

Abstract

A theory has been developed to determine solar cell design parameters in the conventional solar cell equation using measured cell Isc, Imp, Vmp and Voc. The theory overcomes the problem of series resistance becoming negative. It is shown that the diode factor a indeed depends upon cell temperature. The theoretical predictions are in good agreement with experimental observations.

An Improved Nonlinear Five-Point Model for Photovoltaic Modules

“…These are undoubtedly sources of inaccuracies. In turn, the proposed model is consistent with open literature; the diode ideality factor decreases with increasing temperature as issued in [32][33][34], and the series resistance decreases with increasing temperature which agrees with the work in [35], although its variation rate is more important.…”

A straightforward method to extract the shunt resistance of photovoltaic cells from current–voltage characteristics of mounted arrays

“…9 illustrates the R sh values extracted for two cells per panel. The results of this investigation can be summarized as follows: (i) the shunt resistances fall in a surprisingly wide range spanning from 30 to 300 X, which implies that the specific resistance spreads from 2 to 20 kX cm 2 ; (ii) thus, the average cell quality is relatively low, since values larger than 400/500 X are expected in good silicon PV cells [3,4,41]; (iii) over a prescribed module, the cells show a quite uniform R sh distribution; (iv) the measurements were repeated under different irradiation intensities leading to a short-circuit current I sc spanning from 2.0 to 2.5 A, and the extracted R sh values were found to be almost constant, consistently with the conclusion reached in [23].…”

Analytical method for extraction of the single‐diode model parameters for photovoltaic panels from datasheet data

“…In [6], the authors propose an analytical approach for determining the parameters using Taylor series expansion in terms of . In [7], it is presented a Thevenin equivalent circuit to the SDM, where it is found explicit equations to calculate the current generated by the PV arrays.…”

“…In [6], the authors propose an analytical approach for determining the parameters using Taylor series expansion in terms of e (IRs/NsnVt) ( ) . In [7], it is presented a Thevenin equivalent circuit to the SDM, where it is found explicit equations to calculate the current generated by the PV arrays. Approaches for estimating the values of parameters of PV models based on numerical methods and optimisation techniques might have high computational complexity and difficulties to guarantee convergence.…”

“…After some algebraic steps in (12) to isolate R s , we find (9). However, R s can also be given by [7]…”