Dual control of a series static synchronous compensator operating under unbalanced line currents, applied to a novel voltage sourced configuration

This presentation describes a dual control strategy applied to a static synchronous series compensator (SSSC). The dual control theory, which is developed from first principles, is subsequently deployed in the control of a novel voltage-source converter (VSC) configuration operating under unbalanced line currents. This configuration has been used for the first time in a 47-MVAR demonstrator built for the Spanish transmission grid. Then, experimental results are obtained in a 200-kVA small-scale SSSC test bench, connected to an emulated transmission line, deliberately unbalanced for the test.