# Energy Management with Support of PV Partial Shading Modelling in Micro Grid Environments

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Photovoltaic Plant Simulating Model

#### 2.1. Circuital Model

#### 2.2. Solar Irradiation and Shading Pattern

#### 2.3. Maximum Power Point Tracking

## 3. Residential Environment Real Life Based Model

#### 3.1. Reference Environment

#### 3.2. Modelling Approach

- $E{P}_{a}$: amount of energy purchased to supply the entire structure;
- $E{S}_{a}$: amount of energy surplus resulting from the entire structure;
- $ES{p}_{a}$: amount of solar thermal energy production;
- $C{h}_{a}$: amount of energy being stored;
- ${E}_{p}$: the energy purchase price;
- $E{P}_{i}$: energy required by the i-th electrical block with $i=1,2,3$.

## 4. Case Study and Experimental Results

#### 4.1. Power Plant Simulation Case Study

^{2}, and the nominal output power of the plant amounts to 998.4 kWp. The panels are divided in 208 strings of 20 modules each. Moreover, the strings are divided in 13 groups of 16 strings each. The panels face south and with a 30${}^{\circ}$ tilt angle with respect to the horizon. Shadowing from the panels has been avoided by placing the panels far enough from each other. A simplified sketch of the plant surface is presented in Figure 5.

- (a)
- sunny day,
- (b)
- single cloud shading.

- (1)
- (2)
- a macro-block set-up has been modelled by assuming the adoption of one inverter for each subset of panel strings (13 in total);
- (3)
- a micro-block set-up has been modelled by assuming the adoption of one inverter per panel string (208 in total);
- (4)
- a micro-block baseline set-up has been devised by assuming a fixed 15% efficiency level without inverter losses.

- (i)
- Perturb and Observe;
- (ii)
- Incremental conductance;
- (iii)
- Perturb and Observe with Global Point Tracking subroutine;
- (iv)
- Incremental conductance with Global Point Tracking subroutine.

#### 4.2. Power Plant Simulation Results

#### 4.3. Energy Management Simulation Case Study

#### 4.4. Energy Management Simulation Results

## 5. Conclusions

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**Panel strings in heterogeneous irradiation conditions: if the PV panels of a string are subject to different irradiation levels (

**a**); the P-V curve of the string (

**b**) shows different local maxima.

**Figure 2.**Overall P-V curve as the sum of P-V curves of homogeneously irradiated panel sub strings: the P-V curve (

**a**) is the output of the most irradiated panels; the P-V curve (

**b**) is equal to the output of a string subject to an intermediate irradiation level, whereas the least irradiated panels are disconnected; the P-V curve (

**c**) is equal to the output of a string subject to the lowest irradiation level; the local maxima appear because, as the output voltage grows, the less irradiated panels begin to operate limiting the power output of the more irradiated ones; (

**d**) Each PV characteristic.

**Figure 3.**Implementation of the Maximum Power Point (MPP) with support from the Global Peak Tracking approach proposed in [25].

**Figure 4.**Implementation of the Global Peak Tracking subroutine based on [25].

Energy Production | Scenarios | |
---|---|---|

Sunny Day | Single Cloud | |

Reference Energy Yield (kWh/m${}^{2}$) | 3.03 | 2.43 |

Double Inverter (MWh) | 2.74 | 1.47 |

Multi inverter (MWh) | 2.74 | 1.78 |

Single String Inverter (MWh) | 2.85 | 2.26 |

Baseline (MWh) | 3.02 | 2.43 |

Design Approach | Scenarios | |
---|---|---|

Sunny Day | Single Cloud | |

Matched—baseline (€) | 1.38 | 1.47 |

Matched—double inverter (€) | 1.46 | 2.05 |

Mismatched (€) | 1.71 | 2.49 |

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**MDPI and ACS Style**

Severini, M.; Principi, E.; Fagiani, M.; Squartini, S.; Piazza, F.
Energy Management with Support of PV Partial Shading Modelling in Micro Grid Environments. *Energies* **2017**, *10*, 453.
https://doi.org/10.3390/en10040453

**AMA Style**

Severini M, Principi E, Fagiani M, Squartini S, Piazza F.
Energy Management with Support of PV Partial Shading Modelling in Micro Grid Environments. *Energies*. 2017; 10(4):453.
https://doi.org/10.3390/en10040453

**Chicago/Turabian Style**

Severini, Marco, Emanuele Principi, Marco Fagiani, Stefano Squartini, and Francesco Piazza.
2017. "Energy Management with Support of PV Partial Shading Modelling in Micro Grid Environments" *Energies* 10, no. 4: 453.
https://doi.org/10.3390/en10040453