Abstract
DC transformer is the key equipment to interconnect the high voltage dc systems with different voltage levels and build dc grid. Compared with the dc/ac/dc converter based on modular multilevel converter, the non-isolated modular dc/dc converter (MDCC) offers lower cost and higher efficiency, due to the elimination of the ac transformer and reduced submodules (SMs). However, the MDCC based on the half bridge SM (HBSM) can not block the dc short fault. Therefore, the MDCC with the hybrid configuration of the unipolar full-bridge SM (UFBSM) and HBSM, which achieves the dc fault blocking capability, is analysed in this paper, and a damping resistor is introduced in the UFBSM to reduce the ascending voltage of the SM capacitor under dc fault. The fault blocking mechanism of the converter is described, and the fast recovery strategy is presented to ride through the temporary fault. In addition, the design principle of the converter is discussed through a study case. Finally, the simulation performed in Matlab/Simulink verifies the theoretical analysis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
