Fault Protection of Series Active Power Compensation Scheme

The incorporation of Ancillary Services (AS) in modern inverter-based renewable energy systems renders the installation of additional dc/dc or dc/ac converters inevitable. The primary role of these auxiliary converters is to support the power network through managing the Energy Storage Systems (ESS) by applying efficient (dis)charging protocols. The rapid development of power electronics brings at the forefront new converter topologies, which can have simpler connections (in series) rather than the classical parallel configurations. Despite the advantages of those series configurations, in cases of auxiliary converter failure, Renewable Energy Source (RES) production ceases its operation. Thus, to overcome this issue additional circuitry should be added, bypassing the series converter in the fault event. This can be implemented by means of a normally open Solid State Circuit Breaker (SSCB) connected in parallel with the series converter. This non-intrusive method will allow the series configuration to act seamlessly in normal conditions, while ensuring the uninterrupted operation of inverter-based RES in cases of fault of the series converter.