# A Coordinated Voltage Control for Overvoltage Mitigation in LV Distribution Grids

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Challenges of DG Integration

#### 2.1. Voltage Rise

#### 2.2. DG Active and Reactive Power Regulation

**R**and

**X**are the real and imaginary part of the impedance matrix

**Z**.

#### 2.3. Energy Storage System Management

## 3. Coordinated Voltage Control

- ${\mathbf{R}}^{ESS}=Re{\left\{{\mathbf{Z}}_{h}\right\}}_{h\in ESS}$ is the real part of the submatrix ${\mathbf{Z}}_{h}$ obtained when considering only the rows and columns of
**Z**associated to the nodes h where the ESSs are connected. - ${\mathbf{R}}^{DG}=Re{\left\{{\mathbf{Z}}_{h}\right\}}_{h\in DG}$ is the real part of the submatrix ${\mathbf{Z}}_{h}$ obtained when considering only the rows and columns of
**Z**associated to the nodes h where DGs are connected. - ${\mathbf{X}}^{DG}=Im{\left\{{\mathbf{Z}}_{h}\right\}}_{h\in DG}$ is the imaginary part of the submatrix ${\mathbf{Z}}_{h}$ obtained when considering only the rows and columns of
**Z**associated to the nodes h where DGs are connected. - $\Delta {\mathbf{p}}_{+}^{ESS}$, $\Delta {\mathbf{p}}_{+}^{DG}$ and $\Delta {\mathbf{q}}_{+}^{DG}$ are the subvectors of $\Delta {\mathbf{p}}^{ESS}$, $\Delta {\mathbf{p}}^{DG}$ and $\Delta {\mathbf{q}}^{DG}$ associated to the only nodes where ESSs and DG are present, respectively.

#### 3.1. Energy Storage Active Power Control

- (1)
- dual-ascent steps on the dual variables ${\mathbf{\lambda}}_{min}^{p},{\mathbf{\lambda}}_{max}^{p}$;
- (2)
- dual-ascent steps on the dual variables ${\mathbf{\chi}}_{min},{\mathbf{\chi}}_{max}$;
- (3)
- unconstrained minimization on the primal variable $\Delta {\mathbf{p}}_{+}^{ESS}$.

#### 3.2. DG Active Power Control

#### 3.3. DG Reactive Power Control

#### 3.4. DG and ESS Coordination

#### 3.5. Addition of Virtual Nodes

## 4. Simulation Setup

#### 4.1. Distribution Grid

#### 4.2. Load Data

#### 4.3. PV Data and Model

## 5. Simulation Results

## 6. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Von Appen, J.; Braun, M.; Stetz, T.; Diwold, K.; Geibel, D. Time in the sun: The challenge of high PV penetration in the German electric grid. IEEE Power Energy Mag.
**2013**, 11, 55–64. [Google Scholar] [CrossRef] - Ferreira, P.D.; Carvalho, P.M.; Ferreira, L.A.; Ilic, M.D. Distributed energy resources integration challenges in low-voltage networks: Voltage control limitations and risk of cascading. IEEE Trans. Sustain. Energy
**2013**, 4, 82–88. [Google Scholar] [CrossRef] - Navarro-Espinosa, A.; Ochoa, L.F. On the cascading effects of residential-scale PV disconnection due to voltage rise. In Proceedings of the 2014 IEEE PES General Meeting| Conference & Exposition, Washington, DC, USA, 27 July 2014; pp. 1–5. [Google Scholar]
- Resch, M.; Buehler, J.; Klausen, M.; Sumper, A. Impact of operation strategies of large scale battery systems on distribution grid planning in Germany. Renew. Sustain. Energy Rev.
**2017**, 74, 1042–1063. [Google Scholar] [CrossRef] [Green Version] - Bayer, B.; Matschoss, P.; Thomas, H.; Marian, A. The German experience with integrating photovoltaic systems into low-voltage grids. Renew. Energy
**2018**, 119, 129–141. [Google Scholar] [CrossRef] - Mutale, J. Benefits of Active Management of Distribution Networks with Distributed Generation. In Proceedings of the 2006 IEEE PES Power Systems Conference and Exposition, Atlanta, GA, USA, 5 February 2006; pp. 601–606. [Google Scholar]
- Stetz, T.; Marten, F.; Braun, M. Improved low voltage grid-integration of photovoltaic systems in Germany. IEEE Trans. Sustain. Energy
**2012**, 4, 534–542. [Google Scholar] [CrossRef] - European Commission. Do Current Regulatory Frameworks in the EU Support Innovation and Security of Supply in Electricity and Gas Infrastructure? Final Report European Commission. 2019. Available online: https://ec.europa.eu/info/sites/info/files/reportregulatoryfw.pdf (accessed on 16 April 2020).
- Turitsyn, K.; Sulc, P.; Backhaus, S.; Chertkov, M. Local control of reactive power by distributed photovoltaic generators. In Proceedings of the 2010 First IEEE International Conference on Smart Grid Communications, Gaithersburg, MD, USA, 4–6 October 2010; pp. 79–84. [Google Scholar]
- Farivar, M.; Zho, X.; Che, L. Local voltage control in distribution systems: An incremental control algorithm. In Proceedings of the 2015 IEEE International Conference on Smart Grid Communications (SmartGridComm), Miami, FL, USA, 5 November 2015; pp. 732–737. [Google Scholar]
- Bolognani, S.; Carli, R.; Cavraro, G.; Zampieri, S. On the Need for Communication for Voltage Regulation of Power Distribution Grids. IEEE Trans. Control Netw. Syst.
**2019**, 6, 1111–1123. [Google Scholar] [CrossRef] - Antoniadou-Plytaria, K.E.; Kouveliotis-Lysikatos, I.N.; Georgilakis, P.S.; Hatziargyriou, N.D. Distributed and decentralized voltage control of smart distribution networks: Models, methods, and future research. IEEE Trans. Smart Grid
**2017**, 8, 2999–3008. [Google Scholar] [CrossRef] - Brenna, M.; De Berardinis, E.; Delli Carpini, L.; Foiadelli, F.; Paulon, P.; Petroni, P.; Sapienza, G.; Scrosati, G.; Zaninelli, D. Automatic Distributed Voltage Control Algorithm in Smart Grids Applications. IEEE Trans. Smart Grid
**2013**, 4, 877–885. [Google Scholar] [CrossRef] - Bottura, R.; Borghetti, A. Simulation of the Volt/Var control in distribution feeders by means of a networked multiagent system. IEEE Trans. Ind. Inf.
**2014**, 10, 2340–2353. [Google Scholar] [CrossRef] - Zhang, B.; Lam, A.Y.; Domínguez-García, A.D.; Tse, D. An optimal and distributed method for voltage regulation in power distribution systems. IEEE Trans. Power Syst.
**2014**, 30, 1714–1726. [Google Scholar] [CrossRef] [Green Version] - Bolognani, S.; Zampieri, S. A distributed control strategy for reactive power compensation in smart microgrids. IEEE Trans. Automatic Control
**2013**, 58, 2818–2833. [Google Scholar] [CrossRef] [Green Version] - Molzahn, D.K.; Dörfler, F.; Sandberg, H.; Low, S.H.; Chakrabarti, S.; Baldick, R.; Lavaei, J. A survey of distributed optimization and control algorithms for electric power systems. IEEE Trans. Smart Grid
**2017**, 8, 2941–2962. [Google Scholar] [CrossRef] - Palensky, P.; Dietrich, D. Demand side management: Demand response, intelligent energy systems, and smart loads. IEEE Trans. Ind. Inf.
**2011**, 7, 381–388. [Google Scholar] [CrossRef] [Green Version] - Von Appen, J.; Stetz, T.; Braun, M.; Schmiegel, A. Local voltage control strategies for PV storage systems in distribution grids. IEEE Trans. Smart Grid
**2014**, 5, 1002–1009. [Google Scholar] [CrossRef] - Hashemi, S.; ∅stergaard, J. Efficient control of energy storage for increasing the PV hosting capacity of LV grids. IEEE Trans. Smart Grid
**2016**, 9, 2295–2303. [Google Scholar] [CrossRef] [Green Version] - Zarrilli, D.; Giannitrapani, A.; Paoletti, S.; Vicino, A. Energy storage operation for voltage control in distribution networks: A receding horizon approach. IEEE Trans. Control Syst. Technol.
**2017**, 26, 599–609. [Google Scholar] [CrossRef] - Farivar, M.; Chen, L.; Low, S. Equilibrium and dynamics of local voltage control in distribution systems. In Proceedings of the 52nd IEEE Conference on Decision and Control, Florence, Italy, 15 May 2013; pp. 4329–4334. [Google Scholar]
- CENELEC. EN 50160: Voltage Characteristics of Electricity Supplied by Public Electricity Networks; CENELEC: Brussels, Belgium, 2010. [Google Scholar]
- VDE. Erzeugungsanlagen am Niederspannungsnetz, Technische Mindestanforderungen für Anschluss und Parallelbetrieb von Erzeugungsanlagen am Niederspannungsnetz; VDE-AR-N4105; VDE: Frankfurt, Germany, 2011. [Google Scholar]
- Magnússon, S.; Qu, G.; Fischione, C.; Li, N. Voltage control using limited communication. IEEE Trans. Control Netw. Syst.
**2019**, 993–1003. [Google Scholar] [CrossRef] [Green Version] - Bertsekas, D.P. Nonlinear programming. J. Operat. Res. Soc.
**1997**, 48, 334. [Google Scholar] [CrossRef] - Bolognani, S.; Carli, R.; Cavraro, G.; Zampieri, S. Distributed reactive power feedback control for voltage regulation and loss minimization. IEEE Trans. Automatic Control
**2015**, 60, 966–981. [Google Scholar] [CrossRef] [Green Version] - Pau, M.; Angioni, A.; Ponci, F.; Monti, A. A Tool for the Generation of Realistic PV Profiles for Distribution Grid Simulations. In Proceedings of the 2019 International Conference on Clean Electrical Power (ICCEP), Otranto, Italy, 2 July 2019; pp. 193–198. [Google Scholar]
- PYPOWER. Available online: https://pypi.org/project/PYPOWER/ (accessed on 16 April 2020).
- Code Algorithms. Available online: https://git.rwth-aachen.de/acs/public/publications/de-din-coordinated-voltage-control (accessed on 16 April 2020).

**Figure 6.**Generated PV profiles for clear sky and cloudy weather conditions. (

**a**) Photovoltaic (PV) profiles under clear sky conditions. (

**b**) PV profiles under cloudy conditions.

**Figure 7.**Voltage profile of the grid for different control strategies under clear sky conditions. (

**a**) No control (

**b**) Only DG control (

**c**) Both DG and ESSs control.

**Figure 8.**Distributed control applied only to DG. (

**a**) Active power generated by PVs (

**b**) Reactive power generated by PVs.

**Figure 9.**Distributed control applied to both Distributed Generation (DG) and Energy Storage Systems (ESSs). (

**a**) Active power generated by PVs (

**b**) Percentage level of PV energy production.

**Figure 10.**ESS power and DG energy production with prioritized use of the ESS over the DG. (

**a**) Reactive Power generated by PVs. (

**b**) Active power injected by ESSs.

**Figure 11.**ESS power and DG reactive power with prioritized use of the DG over the ESS. (

**a**) Reactive power generated by PVs. (

**b**) Active power injected by ESS.

**Figure 12.**Results for the designed control strategy under cloudy sky conditions. (

**a**) Voltage profile. (

**b**) Active power injected by ESS.

**Figure 13.**Voltage profile without virtual nodes and with virtual nodes. (

**a**) Without virtual nodes (

**b**) With virtual nodes.

**Figure 14.**DG and ESS power injection in scenario without virtual nodes. (

**a**) DG reactive power (

**b**) ESS active power.

**Figure 15.**DG and ESS power injection in scenario with virtual nodes. (

**a**) DG reactive power (

**b**) ESS active power.

ID | Start Node | End Node | Per Unit Resistance | Per Unit Reactance | Node ID | No. Customers |
---|---|---|---|---|---|---|

01 | 1 | 2 | 0.0004 | 0.003172 | 2 | 0 |

02 | 2 | 3 | 0.00108675 | 0.0004095 | 3 | 2 |

03 | 3 | 4 | 0.000426938 | 0.000160875 | 4 | 1 |

04 | 4 | 5 | 0.00087975 | 0.0003315 | 5 | 1 |

05 | 5 | 6 | 0.0009315 | 0.000351 | 6 | 1 |

06 | 3 | 7 | 0.001358438 | 0.000511875 | 7 | 2 |

07 | 7 | 8 | 3.88125E-05 | 0.000014625 | 8 | 6 |

08 | 7 | 9 | 0.000685688 | 0.000258375 | 9 | 1 |

09 | 7 | 10 | 0.00098325 | 0.0003705 | 10 | 3 |

10 | 7 | 11 | 0.000711563 | 0.000268125 | 11 | 3 |

11 | 10 | 12 | 0.00098325 | 0.0003705 | 12 | 2 |

12 | 10 | 13 | 0.0007245 | 0.000273 | 13 | 4 |

13 | 13 | 14 | 0.000414 | 0.000156 | 14 | 2 |

14 | 11 | 15 | 0.000905625 | 0.00034125 | 15 | 1 |

15 | 15 | 16 | 0.000802125 | 0.00030225 | 16 | 2 |

16 | 15 | 17 | 0.000336375 | 0.00012675 | 17 | 3 |

17 | 17 | 18 | 0.000659813 | 0.000248625 | 18 | 1 |

18 | 18 | 19 | 0.000530438 | 0.000199875 | 19 | 2 |

19 | 19 | 20 | 0.000815063 | 0.000307125 | 20 | 5 |

20 | 20 | 21 | 0.000336375 | 0.00012675 | 21 | 2 |

21 | 21 | 22 | 0.00025875 | 0.0000975 | 22 | 4 |

22 | 22 | 23 | 0.000452813 | 0.000170625 | 23 | 4 |

Case | Reactive Power Injection PVs (kVAR) | Active Power Curtailment PVs (kW) | Active Power Injections ESSs (kW) |
---|---|---|---|

No ESSs | −4.3 | −2.1 | 0.0 |

ESSs priority | −0.3 | 0.0 | −5.5 |

PVs priority | −4.4 | 0.0 | −2.0 |

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## Share and Cite

**MDPI and ACS Style**

De Din, E.; Pau, M.; Ponci, F.; Monti, A.
A Coordinated Voltage Control for Overvoltage Mitigation in LV Distribution Grids. *Energies* **2020**, *13*, 2007.
https://doi.org/10.3390/en13082007

**AMA Style**

De Din E, Pau M, Ponci F, Monti A.
A Coordinated Voltage Control for Overvoltage Mitigation in LV Distribution Grids. *Energies*. 2020; 13(8):2007.
https://doi.org/10.3390/en13082007

**Chicago/Turabian Style**

De Din, Edoardo, Marco Pau, Ferdinanda Ponci, and Antonello Monti.
2020. "A Coordinated Voltage Control for Overvoltage Mitigation in LV Distribution Grids" *Energies* 13, no. 8: 2007.
https://doi.org/10.3390/en13082007