Three-phase STATCOM based on a single-phase current source inverter

Abstract

This paper presents a three-phase STATic synchronous COMpensator (STATCOM) based on a current source inverter. Instead of the typical three-phase current bridge inverter it is used a power converter topology with only a single-phase current bridge inverter. A dynamic model of the STATCOM in αβ coordinates is used as a basis for control design. The control system uses a cascade structure where a fast ac current inner loop and a slow dc current control outer loop is used. For the inner loop, is used a sliding mode technique to generate αβ space-vector modulation. This fast and robust controller the ac currents of the STATCOM are actively shaped, being possible to maintain the desired currents even with high ripple DC inductor current. For the outer loop, is used a PI controller. Computer simulations are presented allowing validating the proposed STATCOM and their control system.