OPERATION OF PARALLELED DC-DC CONVERTERS TAKING INTO ACCOUNT CABLE RESISTANCES FOR LOAD SHARING APPLICATIONS

In this paper two DC-DC converters connected in parallel with the purpose of load sharing by applying droop method is considered. This method requires no communication interconnection and compensates for converter parameter variations and imbalances in line impedance. The DC-DC converter input source can be any DC source such as photovoltaic module and wind turbine or fuel cell and it is a closed loop system. In this work proportional-integral (PI) controller, will have their performance evaluated to control the paralleled converters connected to DC micro-grid. The PI controller is tuned by particle swarm optimization (PSO) method. The designing of stable DC-DC converter with primary droop current-sharing control, the stability of the interconnected parallel DC-DC converter system was studied. When the cable resistance of the paralleled DC converters differs, the interconnected system might be unstable and due to this the uneven load sharing occurs. To resolve this issue to some extent without the use of communication lines, a novel technique is applied to parallel DC boost converter in order to optimize the large uneven current sharing. The parallel converter must provide an even load sharing and secondly redundancy. Simulation results are presented in the paper using Mat lab/Simulink to confirm the concept