Distribution system operators (DSO) are facing severe challenges of keeping the voltage levels within operational limits due to the rapid emergence of distributed energy resources (DER) on different distribution network voltage levels. Low-voltage (LV) networks were traditionally operated as autonomous entities with no much insight or control, but high penetration of renewables in most cases introduce serious voltage-quality problems. DSOs have come under the high pressures of voltage-quality provision, which grow even bigger with additional DER installations. This study describes the Elektro Gorenjska, d.d. (EG) role in EU FP7 project titled ‘Increasing the penetration of renewable energy sources in the distribution grid by developing control strategies and using ancillary services’ (INCREASE). During the project, different sets of voltage-control strategies were deployed and tested in order to be compared and evaluated for later day-to-day operations. This study summarises different demonstration cases outcomes and evaluates the benefits of each one.