"Electricity generation from renewable sources is increasing significantly, pushed by the need to meet sustainable energy goals in many countries. Control is a key enabling technology for the deployment of renewable energy systems in smart grids and to guarantee high-performance and reliable operation. To this purpose, a large variety of control strategies have been proposed or are still under investigation, posing the challenge of understanding the effectiveness of the individual solutions and their ability to face operation in critical scenarios, such as in presence of failures. In this paper we focus on the medium voltage grid control and propose a stochastic modeling framework appropriate to represent a variety of voltage control strategies and to quantify their effectiveness in terms of suitably defined metrics to trade among multiple requirements such as imposed grid stability, reliability and cost. We exercise the developed modeling framework on a benchmark grid to show concrete quantification of medium voltage control solutions in interesting grid scenarios. "