Flexible Interlinking Converter With Enhanced FRT Capability for On-Board DC Microgrids

In this paper, a flexible interlinking dc/dc converter with enhanced FRTC is proposed to satisfy the advanced requirements of modern on-board DC MGs; the topology uses a non-isolated switched capacitor-type multilevel converter in combination with a cascaded step up/down converter to facilitate the incorporation of various types of energy storage and/or production units in a DC MG. Overall, a high voltage conversion ratio between the dc bus of the MG and the power unit is achieved. The proposed configuration facilitates the CCM operation of both the power unit and the DC MG and it is characterized by bidirectional power flow capability, enhanced FRTC, zero switching losses for the multilevel converter, limited complexity of the control scheme (compared to the counterpart multilevel solutions) and low real-time communication demands, corresponding so to the increasing flexibility needs of the EMS of modern MGs. The mathematical analysis and the dynamic performance of the control scheme of the proposed topology concept are evaluated via MATLAB/Simulink simulations and real-time CHIL tests, with the use of a 1202 dSPACE platform and an external dsPIC30F4011 microcontroller.