*Review* **Voltage Optimization in PV-Rich Distribution Networks—A Review**

**Marina Dubravac, Krešimir Fekete \*, Danijel Topi´c and Marinko Barukˇci´c**

Faculty of Electrical Engineering, Computer Science and Information Technology Osijek, 31000 Osijek, Croatia **\*** Correspondence: kresimir.fekete@ferit.hr

**Abstract:** There is a rising trend to integrate different types of distributed generation (DG), especially photovoltaic (PV) systems, on the roofs of existing consumers, who then become prosumers. One of the prosumer impacts is voltage violations, which conventional strategies find hard to solve. However, some prosumers, such as those with PV with inverters in their configurations, can actively participate in voltage optimization. To help find the optimal PV inverter setting with the objective of voltage optimization, an optimal power flow (OPF) can be a promising and reliable tool. This paper tries to shed light on the complex problem of voltage optimization in distribution networks (DNs) with PV prosumers. Relevant scientific papers are analyzed and optimization characteristics such as objective functions, variables, and constraints are summarized. Special attention is given to the systematization and classification of papers according to the mathematical formulation of the optimization problem (linear, nonlinear, integer, etc.) and the applied solving methods. Both analytical and computational intelligence optimization methods as well as their advantages and limitations are considered. Papers are also categorized according to the distribution network model used for testing the developed solutions.

**Keywords:** active distribution networks; optimal power flow; prosumers; PV inverter volt/VAR optimization; review
