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

#### **3.1 Fixed topology**

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**.

**Figure 4.** *Different shading pattern a) 10% b) 25% c) 50% d) 75%.*
