RE (Romande Energie), a Swiss DSO (Distribution System Operator), is developing REEL (Réseau en Equilibre Local, French acronym for Network in Local Balance), a demonstration site which will allow to test several innovative technologies. In this contest, a 50 kVA SOP (Soft Open Point) converter has been designed and built by the Universities of Applied Sciences of Western Switzerland (HES SO) of Yverdon-les-Bains and Fribourg. This prototype has been installed on the REEL site of Chapelle-sur- Moudon (Vaud, Suisse), in the first quart of 2021. In this paper, the main hardware and software features, the laboratory tests and the preliminary results of the field tests of the SOP system are presented. Experiments demonstrate the good performances of the SOP control and its usefulness in performing a suitable PQ control.