*2.3. PV Panel Model*

The PV panel comprises numerous cells coupled in a series or parallel to produce greater voltage and current. Figure 3 illustrates the PV panel equivalent circuit.

**Figure 3.** Solar PV module equivalent circuit.

The cells coupled in a series produce the same current. As a result, the panel output current can be written as given in Equation (7).

$$I\_{PV} = I\_{ph} \times N\_p - I\_{d1} \times N\_p \left[ \exp\left[\frac{q\left[V\_{PV}/N\_s + R\_s/N\_p \times I\_{PV}\right]}{A\_1 KT}\right] - 1\right] \tag{7}$$

$$-I\_{d2} \times N\_P \left[ \exp\left[\frac{q\left[V\_{PV}/N\_s + R\_s/N\_p \ I\_{PV}\right]}{A\_2 KT}\right] - 1\right] - \left[V\_{PV}/N\_s + R\_s/N\_p \times I\_{PV}R\_{sl}\right]$$

where *Ns* denotes the number of solar cells combined in a series, while *Np* denotes the number of cells connected in parallel [67,68]. Seven parameters should be calculated in the PV panel circuit; these are *A*1, *A*2, *Rs*, *Rsh*, *Id*1, *Id*2, and *Iph*.
