Analytical averaged loss model of three-phase T-type STATCOM with virtual zero level modulation

This paper presents an analytical model to provide a rapid estimation of the steady-state averaged power loss of a T-type STATCOM with Virtual Zero level Modulation (VZM) to balance the neutral point voltage. A case study is then conducted on a 54kVA rated T-type STATCOM system to investigate the power loss distribution over power devices and variations over switching frequency. A comparison is made in the case study between Silicon IGBT and Silicon Carbide MOSFETs considering the power losses. Downscaled experimental verification is then conducted and shows good consistency with the analytical model. The loss model indicates that VZM reduces the conduction losses of the power converter, but increases the switching losses at the same time.