Reactive Power Limits of Single-Phase and Three-Phase DC-Link VSC STATCOMs under Negative-Sequence Voltage and Current

This paper analyzes and compares the reactive power limits of single- and three-phase configured dc-link Voltage Source Converter (VSC) structures for Static Synchronous Compensator (STATCOM) to operate with negative-sequence voltage and current. The three-level Neutral Point Clamped (3L NPC) is used as an example of a three-phase dc-link topology. Likewise, the Cascaded H-Bridge (CHB) is used as a single-phase dc-link case, in both star and delta configurations. Modular Multilevel Converter is also considered as a combination of both dc-link configurations. The conclusions drawn are generic whichever the Power Electronics Building Block (PEBB) used in each VSC structure.