Performance Assessment of a new Soft Open Point at Bermeo substation during Factory Acceptance Tests

An innovative FACTS device known as Soft Open Point (SOP) rated at 10 MVA is expected to be in operation in 2026 at the Bermeo substation, located in northern Spain. This new grid asset aims to boost grid flexibility and will be connected to a 30 kV distribution network. It utilizes two bidirectional power electronic converters arranged in a back-to-back setup, considered the most adaptable solution to enhance the performance of existing distribution systems. This back-to-back configuration allows precise control of active power (P) flow between the two linked AC terminals, while independently managing reactive power (Q) at both sides. The installation is expected to improve the efficiency of the current grid infrastructure by increasing hosting capacity and enhancing grid reliability. Factory acceptance testing (FAT), including comprehensive functional evaluations, took place in September 2023 at Ingeteam’s high-power testing laboratory in Zamudio, Spain. This paper details and analyses the outcomes of that validation process. The tests carried out covered a wide spectrum of features such as Grid Following (GFL) and Grid Forming (GFM) control modes, islanding capabilities, black start procedures, and post-islanding resynchronization.