Research on a 4000-V-Ultrahigh-Input-Switched-Mode Power Supply Using Series-Connected MOSFETs

A 4000-V-ultrahigh-input voltage-switched-mode power supply (UHV-SMPS) using series-connected MOSFETs is designed in this paper. The main contributions of the proposed scheme include the common-mode interference modeling of the multiswitch structure, voltage balance of the switches and driving method. First, the common-mode interference of UHV-SMPS is evaluated by a high-frequency equivalent model of the proposed scheme. Then, a detailed multiswitch common-mode electromagnetic interference mathematical model is derived and the interference quantity is calculated according to the coupling of series-connected switches. Second, a new mathematical regulation for passive snubber circuit is proposed to realize input voltage balance. Through the regularity of the equivalent parasitic capacitances, the design of compensatory capacitance and voltage balance can realized with ease. Third, a novel driving method based on integrated pulse transformer is proposed. It can achieve both good consistency to the gate signals of MOSFETs and ultrahigh isolation voltage in the wide range input applications. Finally, the experimental results obtained from a 300-4000 V wide range input prototype verified the feasibility of the proposed scheme and accuracy of the theoretical analysis.