# Improving the Efficiency of Partially Shaded Photovoltaic Modules without Bypass Diodes

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## Abstract

**:**

## 1. Introduction

## 2. Methodology

_{2}→${S}_{B}$, ${S}_{3}$→${S}_{D}$, and ${S}_{E}$, ${S}_{4}$→${S}_{F}$${S}_{G}$${S}_{H}$ and $SI$. Therefore, we can claim that the nine switches were replaced with four different switches to maintain the same operation at lower system complexity. The actual connections of the switches are depicted in the same figure.

## 3. Results and Discussion

^{®}was used in this article to prove the concept of the proposed model of the PV modules. From the current–voltage characteristics, the open-circuit voltage, the short-circuit current, and the maximum-power point values were extracted. The switches were controlled as explained in Table 1, and their instantaneous states are depicted in Figure 6. Passive switches were used in this work to mitigate the risk of any circuit failure. In fact, the four switches could be simplified into two single-pole double-throw (SPDT) switches. The switches ${S}_{1}$ and ${S}_{2}$ complemented the corresponding states of the switches S

_{4}and S

_{3}, respectively. Therefore, ${S}_{1}$ and ${S}_{4}$ could be combined as one SPDT switch, while the switches ${S}_{1}$ and ${S}_{4}$ could be combined as a second SPDT switch. At each time slot, the states of the switches determined which cells were to be connected. Figure 7 shows the complete model, consisting of 36 identical cells except cell 9, which was 80% shaded. The simulation of the PV module for the five cases is depicted in Figure 8, which was done to extract the corresponding electrical parameters from the current–voltage characteristics in every case. As a figure of merit to compare the power losses due to shading, we assumed the power ${P}_{(max,Case(a\left)\right)}$ in case (a) as a reference for the calculation power losses as follows:

## 4. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## References

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**Figure 1.**PV module comprising ${N}_{s}$ series-connected cells and ${N}_{p}$ parallel-connected strings.

**Figure 2.**Current and power characteristics of a PV cell and the corresponding module comprising ${N}_{s}$ series-connected cells and ${N}_{p}$ parallel-connected strings.

**Figure 3.**Junction box and the corresponding actual connections of the proposed switches (

**a**) by implementing nine switches (labeled ${S}_{A}$, ${S}_{B}$, ... ${S}_{I}$) and (

**b**) by replacing them by only four switches to maintain the same function.

**Figure 4.**Different modes of operations for the proposed PV module, where the voltage and the current could be scaled based on the load’s electrical needs.

**Figure 5.**Five cases for the PV module (

**a**) Conventional module without shading; (

**b**) conventional module with shading; (

**c**) mode 1: the same cell is shaded in the presence of two bypass diodes; (

**d**) mode 2: the same cell is shaded without bypass diodes; (

**e**) mode 3: the same cell is shaded without bypass diodes.

**Figure 6.**States of the switches as explained in Table 1.

**Figure 8.**Current–voltage characteristics for the PV module for the five cases in Figure 5.

Mode | ${\mathit{N}}_{\mathit{s}}$ | ${\mathit{N}}_{\mathit{p}}$ | States of Switches | Module Voltage | Module Current |
---|---|---|---|---|---|

Mode 1 | 36 | 1 | ${S}_{1}$ and ${S}_{2}$ are closed | Highest | Lowest |

Mode 2 | 18 | 2 | ${S}_{1}$ and ${S}_{3}$ are closed | Moderate | Moderate |

Mode 3 | 9 | 4 | ${S}_{3}$ and ${S}_{4}$ are closed | Lowest | Highest |

Mode | ${\mathit{V}}_{\mathit{o}\mathit{c}}$ | ${\mathit{I}}_{\mathit{s}\mathit{c}}$ | ${\mathit{P}}_{\mathit{m}\mathit{a}\mathit{x}}$ | ${\mathbf{\Delta}}_{\mathit{P}}$ |
---|---|---|---|---|

$\left(\mathbf{V}\right)$ | $\left(\mathbf{A}\right)$ | $\left(\mathbf{W}\right)$ | (%) | |

36/60/72 Cells | 36/60/72 Cells | 36/60/72 Cells | 36/60/72 Cells | |

Conventional, | 21.6/36/43.2 | 7.34/7.34/7.34 | 120.6/200.98/241.19 | - |

without shading | ||||

Conventional, | 21.54/35.94/43.14 | 1.47/1.47/1.47 | 30.69/51.44/61.82 | 74.55/74.41/74.37 |

with shading | ||||

Mode 1 | 21.54/35.94/43.14 | 7.34/7.34/7.34 | 45.96/119.27/145.99 | 61.89/40.66/39.47 |

Mode 2 | 10.77/11.98/14.38 | 8.81/14.68/14.68 | 73.41/139.21/167.03 | 39.13/30.73/30.75 |

Mode 3 | 5.39/6/7.2 | 23.49/22.02/22.02 | 96.96/100.49/120.57 | 19.59/50/50.01 |

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**MDPI and ACS Style**

Tarabsheh, A.A.; Akmal, M.; Ghazal, M.
Improving the Efficiency of Partially Shaded Photovoltaic Modules without Bypass Diodes. *Electronics* **2021**, *10*, 1046.
https://doi.org/10.3390/electronics10091046

**AMA Style**

Tarabsheh AA, Akmal M, Ghazal M.
Improving the Efficiency of Partially Shaded Photovoltaic Modules without Bypass Diodes. *Electronics*. 2021; 10(9):1046.
https://doi.org/10.3390/electronics10091046

**Chicago/Turabian Style**

Tarabsheh, Anas Al, Muhammad Akmal, and Mohammed Ghazal.
2021. "Improving the Efficiency of Partially Shaded Photovoltaic Modules without Bypass Diodes" *Electronics* 10, no. 9: 1046.
https://doi.org/10.3390/electronics10091046