The Closedloop Control of a Switched Coupled Inductor DC–DC Step-Up Converter for Micro Source Applications

A step-up dc-dc converter with high voltage gain is handling in this paper. Nowadays renewable energy sources are widely used in Distributed Generation (DG) systems. DG systems are composed of micro sources like photovoltaic (PV) cells, fuel cells, wind power etc. However fuel cells and photovoltaic cells are low voltage sources to provide enough dc voltage for generating ac utility voltage. PV cells can be connected in series in order to obtain a large output voltage. But the main drawback is the efficiency is degraded due to the panel mismatch and partial shadowing. The PV panel parallel connected structure is more efficient than the series-connected configuration. Meanwhile, only a low voltage is generated with parallel connected Configuration. So for the aforementioned problem, high step up converters are used as a solution. In order to obtain high voltage gain, employing a switched coupled inductor and a switched capacitor in to one converter. The coupled inductor charges the capacitor, the voltage gain can be effectively increased, and the turns ratio of the coupled inductor can be also reduced. Beside from high voltage gain, lower conduction loss and higher power conversion efficiency is also offered as compared to conventional dc-dc converter. The steady state analysis and operating principles in continuous conduction mode are discussed. There are two modes of operation for this converter based on the charging and discharge of the coupled inductor. To study the performance of the switched coupled inductor high step up DC-DC converter with closed loop control, simulations has been carried out in MATLAB 2013 environment. Thus these current and voltage waveforms agreed with the operating principles and the steady-state analysis. The simulation results are tested at low power. The 12V input voltage is stepped up to output voltage of 132V.