Generalised predictive control for a 12-bus network using a neutral-point clamped voltage-source-converter UPFC

This presentation describes the application of a unified power flow controller (UPFC) to a case study of a 12-bus high-power network. The UPFC shunt converter employs eight 3-level neutral-point clamped (NPC) voltage-source converters (VSC) and 12 single-phase three-winding phase-shifting transformers (PST), generating a 48-pulse output voltage. The 3-phase H-bridge series converter shares the same DC link with the shunt one. The novel feature of this work lies in the use of a model-based generalised predictive current control law to the shunt converter for voltage and power flow control which has shown superior performance without additional filters compared to a P+I control scheme. In addition with the phase shift and switching angle control of each NPC-VSC output voltage, the topology offers improved harmonic performance and a zero-sequence blocking transformer is used for total triplen harmonics elimination.