Analytical averaged loss model of a three-level T-type converter

This paper has developed an analytical averaged loss model for a three-level T-type converter. Both the conduction loss and switching loss have been analysed. Apart from reduced output harmonics due to three-level operation, the T-type converter benefits from lower switching loss as a result of using of devices with lower voltage ratings and switching only half of the dc-link voltage. The loss distribution among the devices has been investigated with various modulation index and power factor. The T-type converter efficiency has also been evaluated against a two-level converter and a three-level neutral-point-clamped converter, where the T-type converter shows higher efficiency up to 30kHz switching frequency and can achieve 97% efficiency at 50kHz.