High Voltage Power Supply Using a T-Type Parallel Resonant DC–DC Converter

In this research, the study and implementation of the t-type parallel resonant dc-dc converter in high-voltage power supplies for travelling wave tube applications is presented. The proposed converter shares the benefits of the traditional full-bridge parallel resonant dc-dc converter, such as zero voltage switching on primary side switches over a wide load range, symmetric three-level voltage across the transformers primary winding, and integration of transformers leakage inductance and winding capacitance during its basic operation. However, only two switches are subjected to the input voltage, while the other two switches are subjected to half of the input voltage. Theoretical analysis, commutation analysis, and design guidelines are presented. The theoretical analysis validation and efficiency investigation are conducted through a t-type parallel resonant converter prototype, which operates with 1.5 kW and 97.12% efficiency. Hence, experimental results of a travelling wave tube power supply prototype operating with 1.5 kW of output power, 400 Vdc input, and four high output voltages, whose measurements results are V _o1 = 1382 V, V _o2 = 3505 V, V _o3 = 1504 V, and V _o4 = 3338 V, confirm the feasibility of the proposed implementation.