Performance of the 6.6-kV 200-kVA Transformerless SDBC-Based STATCOM Using 3.3-kV SiC-MOSFET Modules for Reactive-Power Compensation

This paper provides an experimental discussion on the 6.6-kV, 200-kVA transformerless static synchronous compensator (STATCOM) based on a modular multilevel single-delta bridge-cells (SDBC) converter that is also referred to as an "SDBC converter" shortly. This STATCOM has multi-functions to control both positive-sequence and negative-sequence reactive power for voltage-flicker mitigation, as well as to achieve power-factor correction of a load(s) in industrial power systems. This paper pays more attention to the latter, showing satisfactory performance under both steady-state and transient conditions. The combination of the SDBC converter with the latest 3.3-kV SiC-MOSFET modules allows both manufacture and customer to put the STATCOM into practical use because no line-frequency transformer is required for installing it on medium-voltage utility and industrial power systems.