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


#### **Table 1.**

*Solar Cells - Theory, Materials and Recent Advances*

considered portable and easy to use [5]. Hence, the PV based power source is used in a wide range of applications that include residential and commercial building, drones, vehicle, satellites, embedded systems, sensors and many others [9].

cells, leading to them consuming the power instead of generating it [13, 14].

ing of PV cells in the module degenerate the solar panel's performance [12].

**2. SPICE based PV cell and module modeling**

shown in **Figure 1** are the internal resistance of the PV Cell.

**2.1 Equivalent circuit model of a PV cell**

Additionally, the partial shading condition can cause hotspot generation in the panel's neighboring PV cells [15–17]. This hotspot can even instigate a fire hazard [18–20]. Mismatch in the PV cells in the PV module can also create abnormalities like the partial shading conditions [14]. Hence, to prevent such a phenomenon from happening, the PV modules are equipped with bypass and blocking diode [2, 9, 21]. The bypass diode causes bypassing of the shaded or damage PV cells in the panel [22]. Simultaneously, the blocking diode prevents the current from flowing in the reverse direction in case of a mismatch in the output voltage, which can lead to forward basing of the PV cells [21]. Similarly, faults such as open and short circuit-

Due to all these abnormalities that reduce the PV panel's performance, it is desirable to model a PV module that can emulate its electrical characteristics to derive a better way to tackle them. Also, equivalent modeling helps to better understand the PV panel characteristics before they are being deployed for real-world applications.

To model the PV cell, a SPICE based 2-diode based equivalent circuit is used as shown in **Figure 1** [23]. All the parameters shown in **Figure 1**, are presented in **Table 1** [23]. Two diode-based PV cell modeling techniques are selected over single diodes since they are considered more accurate [24]. The resistance Rs and Rp as

The current iPV *ge*nerated by the PV cell, as shown in **Figure 1**, can be

The PV-based power source is not ideal and performance can cause many anomalies [10, 11]. One of the most significant issues that affect PV modules performance is the shading caused due to clouds, physical objects, and living beings [10, 11]. Generally, there are two types of shading, complete shading and partial shading [12]. The complete shading occurs when the whole PV module is under the shade. If only a few of the PV cells are under the shade, it results in partial shading conditions. Both of these shading types reduce the power efficiency of PV modules. However, the partial shading condition can have much more severe after effects [13]. The current flow in a row of PV cells connected in series is governed by the PV cells that are affected by the shade [13, 14]. This phenomenon can lead to forward biasing of unshaded PV

**20**

**Figure 1.**

*2-diode based equivalent PV cell model.*

computed by:

*The parameters descriptions for modeling PV cells and module, their assumed constant value, and units.*

$$\dot{\mu}\_{PV} = I\_{ph} - I\_{d1} - I\_{d2} - \frac{\nu\_{PV} + i\_{pv}R\_S}{R\_P} \tag{1}$$

Where the Id1 and Id2 can be computed by:

$$I\_d = I\_s \left( e^{\left(\frac{p\_{PV} \times t\_{ps} R\_5}{A \times V\_T}\right)} - \mathbf{1} \right) \tag{2}$$

The total photon current of a PV cell is dependent on the area of the PV cell, short-circuit current density of the PV cell, and the solar irradiance. The following equation can compute the total photon current for a given PV cell:

$$I\_{\rm Ph} = A\_{\rm PV} \times J\_{\rm SC} \times \frac{G}{G\_{\rm Sh}} \tag{3}$$

The current vs. voltage (I-V) and power vs. voltage (P-V) characteristics obtained for a single PV cell using SPICE-based equivalent PV cell are shown in **Figure 2**. The SPICE simulation uses Eq. (1), Eq. (2), and Eq. (3).
