# An Enhanced Adaptive Perturb and Observe Technique for Efficient Maximum Power Point Tracking Under Partial Shading Conditions

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## Abstract

**:**

## Featured Application

**This work presents a perfect technique for optimizing the operation of photovoltaic systems by continuously extracting the maximum power even under the worst cases of atmospheric variations. The proposed technique provides a robust solution that can overcome the drawbacks of power tracking algorithms under partial shading conditions, such as the failure of actual maximum power extraction, low tracking speed, complexity in the required computations and in implementation, low accuracy, and high oscillation around the tracked maximum power. Therefore, the proposed algorithm will enable the best performance for any applied photovoltaic configuration without any extra cost and complexity, thus enhancing the utilization of photovoltaic renewable energy for significant applications.**

## Abstract

## 1. Introduction

## 2. Partial Shading Effect Implementation

^{2}.

## 3. DC/DC Boost Converter Design

**Selection of the resistor**: The load resistance $\left({R}_{L}\right)$ of the boost converter is related to the ideal internal resistance of the PV array at the MPP $\left({R}_{MPP}\right)$ by the following equation, as illustrated in [33]:

^{2}and the lower was at G = 200 W/m

^{2}[35]. Figure A1 in Appendix A illustrates the characteristic alteration of the curves of P–V, I–V, and ideal internal resistance for the PV array under three illumination intensities. The MPP declined from 640.6 W to 70.4 W when the radiation level was reduced from 1000 W/m

^{2}to 200 W/m

^{2}. Accordingly, the R

_{MPP}rose from 7.74 Ω to 35.5 Ω; thus, the load resistance value was selected as 50 Ω for this work, to be greater than ${R}_{MPP}$ in the case of lowermost illumination.

**Selection of the inductor:**The value of the boost inductor is chosen depending on the maximum amount of acceptable current ripple at the MPP in the case of uppermost solar radiation (1000 W/m

^{2}) [34]. When the inductor value is high, the output current ripple will be low, and the opposite is also true, as shown in Equation (6). The switching frequency ${f}_{s}$ was fixed at 10 kHz in this work, in order to reduce the oscillations at the MPP, and the value of the inductor was considered for input current ripple $\mathsf{\Delta}Ipv$ of $1\%$ [35]. Therefore, the minimum value of the inductor was designed as follows [34,35,36]:

**Selection of the capacitor:**The minimum value of the output capacitor was determined according to the output voltage ripple $\mathsf{\Delta}{V}_{O}$ of $1\%$ as given below [34,35,36,37]:

## 4. Enhanced P&O Algorithm

#### 4.1. The Conventional P&O Technique

#### 4.2. Enhanced P&O MPPT

## 5. Simulation Results

#### 5.1. Case One: Weak Shading Pattern

^{2}radiation), while one receives 800 W/m

^{2}and one receives 600 W/m

^{2}. The arrangement is illustrated in Table 2. Multiple maxima occur in the P–V characteristics. The location of the GMPP is shown in the characteristics in Figure 7. Figure 8 illustrates the simulation results for this case with a performance comparison between the proposed technique and the conventional P&O and IC techniques.

#### 5.2. Case Two: Moderate Partial Shading Pattern

^{2}radiation), while two receive 800 W/m

^{2}and two receive 500 W/m

^{2}. The arrangement is illustrated in Table 2. Multiple maxima occur in the P–V characteristics. The location of the GMPP is shown in the characteristics in Figure 9. Figure 10 illustrates the simulation results for this case with a performance comparison between the proposed technique and the conventional P&O and IC techniques.

#### 5.3. Case Three: Strong Partial Shading Pattern

^{2}radiation), while one receives 800 W/m

^{2}, two receive 600 W/m

^{2}, two receive 400 W/m

^{2}, and one receives 200 W/m

^{2.}The arrangement is illustrated in Table 2; it creates five peaks in the P–V characteristics curve and forms a more complex situation for tracking the GMPP. The GMPP is located as shown in the characteristics in Figure 11. The simulation results for Case Three with a performance comparison between the proposed technique and the conventional P&O and IC techniques are illustrated in Figure 12.

#### 5.4. Case Four: Strong Partial Shading Pattern

^{2}radiation), while two receive 600 W/m

^{2}and four receive 400 W/m

^{2}. The arrangement is illustrated in Table 2. Four maxima occur in the P–V characteristics. The location of the GMPP is shown in the characteristics in Figure 13. The simulation results for Case Four with a performance comparison between the proposed technique and the conventional P&O and IC techniques are illustrated in Figure 14.

#### 5.5. Discussion of the Simulation Results

## 6. Analysis of the Proposed Enhanced P&O for Partial Shading

## 7. Additional Configuration Testing

## 8. Future Work

## 9. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Appendix A

## References

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**Figure 3.**Simulink model of the maximum power point tracking (MPPT) controller using a boost converter.

**Figure 8.**The simulation results of the proposed technique and the conventional P&O and incremental conductance (IC) techniques for Case One: (

**a**) Tracked output power; (

**b**) Output voltage of the boost converter; (

**c**) Duty cycle behaviors.

**Figure 10.**The simulation results of the proposed technique and the conventional P&O and IC techniques for Case Two: (

**a**) Tracked output power; (

**b**) Output voltage of the boost converter; (

**c**) Duty cycle behaviors.

**Figure 12.**The simulation results of the proposed technique and the conventional P&O and IC techniques for Case Three: (

**a**) Tracked output power; (

**b**) Output voltage of the boost converter; (

**c**) Duty cycle behaviors.

**Figure 14.**The simulation results of the proposed technique and the conventional P&O and IC techniques for Case Four: (

**a**) Tracked output power; (

**b**) Output voltage of the boost converter; (

**c**) Duty cycle behaviors.

**Figure 15.**Performance of the combined sequence of Cases Three, Two, Four, and One in terms of (

**a**) the output power, (

**b**) the output voltage, and (

**c**) the duty cycle.

**Figure 16.**Shading condition cases of two configurations: (

**a**) The first case of (8S); (

**b**) The second case of (8S); (

**c**) The first case of (4S); and (

**d**) The second case of (4S).

**Figure 17.**(

**a**) Scenario of case “a” of the (8S) PV array; (

**b**) The extracted power by the proposed technique and the conventional P&O and IC techniques; (

**c**) The voltage at the boost converter output; (

**d**) The duty cycle behaviors.

**Figure 18.**(

**a**) Scenario of case “b” of the (8S) PV array; (

**b**) The extracted power by the proposed technique and the conventional P&O and IC techniques; (

**c**) The voltage at the boost converter output; (

**d**) The duty cycle behaviors.

**Figure 19.**(

**a**) Scenario of case “c” of the (4S) PV array; (

**b**) The extracted power by the proposed technique and the conventional P&O and IC techniques; (

**c**) The voltage at the boost converter output; (

**d**) The duty cycle behaviors.

**Figure 20.**(

**a**) Scenario of case “d” of the (4S) PV array; (

**b**) The extracted power by the proposed technique and the conventional P&O and IC techniques; (

**c**) The voltage at the boost converter output; (

**d**) The duty cycle behaviors.

Irradiance (W/m^{2}) | V_{mpp} (V) | I_{mpp} (A) | P_{mpp} (W) | R_{mpp} (Ω) | D_{mpp} | V_{out} (V) | I_{out} (A) | R_{L} (Ω) | L (mH) | C (µF) |
---|---|---|---|---|---|---|---|---|---|---|

1000 (Higher) | 70.4 | 9.1 | 640.6 | 7.74 | 0.61 | 179 | 3.6 | 50 | 1.6 | 500 |

200 (Lower) | 63.57 | 1.793 | 114 | 35.5 | 0.16 | 75.7 | 1.5 |

**Table 2.**Incident irradiation for the PV system array with the corresponding power at the global maximum power point (GMPP).

Case | Irradiation of the First Four Series Modules | Irradiation of the Second Four Series Modules | Power at GMPP |
---|---|---|---|

One (Weak shading) | [1000,1000,1000,800] | [1000,1000,1000,600] | 490.9 W |

Two (Moderate shading) | [1000,1000,800,800] | [1000,1000,500,500] | 435.5 W |

Three (Strong shading) | [1000,1000,600,400] | [800,600,400,200] | 257.4 W |

Four (Strong shading) | [1000,1000,600,400] | [600,400,400,400] | 263.8 W |

Case | Irradiation of the Parallel First and Second Series Modules | Ideal Power at GMMP (A) | Tracked Power at GMMP (B) | $\mathbf{Efficiency}\left(\frac{\mathbf{B}}{\mathbf{A}}\times 100\right)$ | Tracking Speed |
---|---|---|---|---|---|

One (Weak shading) | [1000,1000,1000,800] [1000,1000,1000,600] | 490.9 W | 490.9 W | 100% | 0.13 s |

Two (Moderate shading) | [1000,1000,800,800] [1000,1000,500,500] | 435.5 W | 435.5 W | 100% | 0.139 s |

Three (Strong shading) | [1000,1000,600,400] [800,600,400,200] | 257.4 W | 257.4 W | 100% | 0.137 s |

Four (Strong shading) | [1000,1000,600,400] [600,400,400,400] | 263.8 W | 263.8 W | 100% | 0.127 s |

Case Three (Strong Shading 0–0.4 s) | 257.4 W | 257.4 W | 100% |

Case Two (Moderate shading 0.4–0.8 s) | 435.5 W | 435.5 W | 100% |

Case Four (Strong shading 0.8–1.2 s) | 260.3 W | 263.8 W | 98.67% |

Case One (Weak shading 1.2–1.6 s) | 490.9 W | 490.9 W | 100% |

Ref. | Year | Converter Type | Steady State Oscillations | Speed of Tracking | Tracking Efficiency | Complexity |
---|---|---|---|---|---|---|

Proposed algorithm | 2020 | Boost Converter | Nil | Highest | Highest | Very Low |

[1] | 2019 | DC/DC Buck converter | Low | High | High | Reasonable |

[27] | 2018 | Boost Converter | Low | High | High | High |

[17] | 2015 | Boost Converter | Low | High | Average | Reasonable |

[16] | 2015 | SEPIC converter | Low | High | Low | Medium |

[18] | 2012 | Buck converter | High | High | Medium | High |

[28] | 2018 | Boost converter | High | High | Medium | High |

[10] | 2017 | Boost converter | Medium | High | Medium | High |

[9] | 2016 | SEPIC converter | Low | High | High | High |

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## Share and Cite

**MDPI and ACS Style**

Mahmod Mohammad, A.N.; Mohd Radzi, M.A.; Azis, N.; Shafie, S.; Atiqi Mohd Zainuri, M.A.
An Enhanced Adaptive Perturb and Observe Technique for Efficient Maximum Power Point Tracking Under Partial Shading Conditions. *Appl. Sci.* **2020**, *10*, 3912.
https://doi.org/10.3390/app10113912

**AMA Style**

Mahmod Mohammad AN, Mohd Radzi MA, Azis N, Shafie S, Atiqi Mohd Zainuri MA.
An Enhanced Adaptive Perturb and Observe Technique for Efficient Maximum Power Point Tracking Under Partial Shading Conditions. *Applied Sciences*. 2020; 10(11):3912.
https://doi.org/10.3390/app10113912

**Chicago/Turabian Style**

Mahmod Mohammad, Altwallbah Neda, Mohd Amran Mohd Radzi, Norhafiz Azis, Suhaidi Shafie, and Muhammad Ammirrul Atiqi Mohd Zainuri.
2020. "An Enhanced Adaptive Perturb and Observe Technique for Efficient Maximum Power Point Tracking Under Partial Shading Conditions" *Applied Sciences* 10, no. 11: 3912.
https://doi.org/10.3390/app10113912