Control and performance of a single-phase dual active half bridge converter based on 15kV SiC IGBT and 1200V SiC MOSFET

A single-phase Dual Active Half Bridge (DAHB) DC-DC converter topology is evaluated for medium voltage (MV) application. A 15kV SiC-IGBT based three-level half-bridge is connected to the high voltage (HV) primary side of a high frequency (HF) transformer operating at 10kHz link-frequency. A 1200V SiC-MOSFET based two-level H-bridge is connected on the low voltage (LV) secondary side. This topology requires fewer switches and is suitable for MV application particularly with high step-down ratio where HF transformer may have considerable parasitics. It offers advantage of half blocking voltage requirement per device on the HV side and a simpler transformer saturation protection implementation. This paper also presents a robust D-Q based inner current control technique for the single phase DAB. The converters on both HV and LV side of the DAHB, can also be switched in 60° zero quasi-square mode to eliminate 3^rd harmonic voltage. The square and 60° modes of operation are compared. The DAHB converter topology and controls are validated with simulation results followed by experimental results.