**2.2 Equivalent modeling of PV module**

A series–parallel topology is used to model a PV module using the equivalent PV cell shown in **Figure 1**. The total number of PV cells in the PV panel is equal to N. The number of PV cells connected in series is equal to Ns. The Ns number of series connected PV cells are then tied together to form a PV panel or module. The total number of PV cells connected in parallel is equal to Np. Thus, the number of PV cells in a PV module is given by:

$$\mathbf{N} = \mathbf{N}\_{\mathcal{S}} \times \mathbf{N}\_{p} \tag{4}$$

**Figure 2.** *a) Current vs. voltage (I-V) characteristics of PV cell b) power vs. voltage (P-V) characteristics of PV cell.*

#### **Figure 3.**

*A PV module of Ns x Np (number of PV cells in series x number of PV cells in parallel) configuration a) double-diode based equivalent PV module b) column decomposition c) row decomposition d) approximate equivalent model.*

**23**

**Figure 4.**

*Different shading pattern a) 10% b) 25% c) 50% d) 75%.*

*Modeling of Photovoltaic Module*

*DOI: http://dx.doi.org/10.5772/intechopen.97082*

based model shown in **Figure 3d)**.

it is given by Eq. (5).

**shading**

**3.1 Fixed topology**

If all the PV cells in a PV module are homogenous and are receiving an identical solar irradiance, it can be modeled in **Figure 3** [25]. The total current generated from the PV module with Ns number of PV cells in series and Np number of PV cells in parallel can be modeled by using Eq. (1) and the equivalent double diode

The photon current shown in **Figure 3** is given by the summation of photon current across each column in the PV module. Thus, the total photon current of a PV module is equal to the Np times the single PV cell's photon current. In the partial shading in the PV module, the current across the series connected PV cell is determined by the current generated from the shaded PV cells. Thus, in this case, the PV module's total photon current is not equal to Np times the photon current. Instead,

( )

*Total I mi I* (5)

1 n

= =∑ *NP PH Ph i*

**3. Different types of topologies for creating a PV module and effect of** 

Typically, the topology used for creating PV modules from a single PV cell is mostly fixed. To reduce the partial shading and mismatch impact, bypass diode is connected across PV cells in the panel to reduce its impact on power generation [22]. To reduce the effect of partial shading condition, different techniques of placing bypass diode were analyzed [26]. However, they make the PV module much more complicated for mass production. There are different topologies of connecting PV cells in the module and these are important for understanding the effectiveness of different topologies for mitigating the ailing effect of partial shading condition, the shading pattern shown in **Figure 4** is used [27]. For simplifying the simulation, the number of series connected PV cells is equal to 4, and the number of parallel connected PV cells is 5, i.e., NS is equal to 4 and NP is equal to 5. Thus, the total number of PV cells in the PV module is considered 20, as shown in **Figure 4**.

*Modeling of Photovoltaic Module DOI: http://dx.doi.org/10.5772/intechopen.97082*

*Solar Cells - Theory, Materials and Recent Advances*

A series–parallel topology is used to model a PV module using the equivalent PV cell shown in **Figure 1**. The total number of PV cells in the PV panel is equal to N. The number of PV cells connected in series is equal to Ns. The Ns number of series connected PV cells are then tied together to form a PV panel or module. The total number of PV cells connected in parallel is equal to Np. Thus, the number of PV

*a) Current vs. voltage (I-V) characteristics of PV cell b) power vs. voltage (P-V) characteristics of PV cell.*

*A PV module of Ns x Np (number of PV cells in series x number of PV cells in parallel) configuration a) double-diode based equivalent PV module b) column decomposition c) row decomposition d) approximate* 

*NN N* = ×*S P* (4)

**2.2 Equivalent modeling of PV module**

cells in a PV module is given by:

**22**

**Figure 3.**

*equivalent model.*

**Figure 2.**

If all the PV cells in a PV module are homogenous and are receiving an identical solar irradiance, it can be modeled in **Figure 3** [25]. The total current generated from the PV module with Ns number of PV cells in series and Np number of PV cells in parallel can be modeled by using Eq. (1) and the equivalent double diode based model shown in **Figure 3d)**.

The photon current shown in **Figure 3** is given by the summation of photon current across each column in the PV module. Thus, the total photon current of a PV module is equal to the Np times the single PV cell's photon current. In the partial shading in the PV module, the current across the series connected PV cell is determined by the current generated from the shaded PV cells. Thus, in this case, the PV module's total photon current is not equal to Np times the photon current. Instead, it is given by Eq. (5).

$$Total\ I\_{\rm PH} = \sum\_{i=1}^{N\_{\rm P}} \min\left(I\_{\rm Ph}\right) \tag{5}$$
