Analysis of Self-sharing of Currents in Steady-state of IPOP Connected Modular SEPIC Converter in DCM

摘要

This paper covers the analysis of a modular association of dc-dc SEPIC converter with parallel-parallel configuration, operating in discontinuous conduction mode. The main attribute of the proposed system is its ability to provide self-sharing of the currents on both sides of each individual converter, without current control loop, and then keeping the system in stable operation. This does not occur when SEPIC converter operates in continuous conduction mode considering parametric differences among modules; in CCM, one module can take the current of other modules and process the whole power of system. The proposed association of DCM SEPIC converters makes possible the use of the converter for higher power levels without increase the current and voltage stress in the components, and without the use of a current control loop, which simplifies the control system to these converters. The theoretical study of self-sharing of current mechanism to SEPIC converters in DCM is included in the paper. Furthermore, the association is verified by numerical simulation and experimental results, which are obtained from a converter with three modules, with 100 V input voltage, 200 V output voltage, 600 W rated power and switching frequency of 25 kHz.