As the size of as photovoltaic (PV) power plants have been gradually increasing in the last few decades, interests in multiphase converters for PV application has been escalated. Due to current sharing by the adding phase, the multiphase converters are suitable for PV system to reduce conduction losses and increase system efficiency. However, the adding phase can be disadvantage for the converters at light load condition. Especially for PV applications which rely on changeable irradiation or temperature condition, low efficiency at light load condition is a critical problem on the PV system. This thesis demonstrates the improvement and advantages of interleaved boost converter compared with conventional boost converter. Moreover, a new phase shedding control method of an interleaved boost converter as PV pre-regulator is proposed as a way to improve the efficiency of the converter at light load condition. The efficiency improvement of the interleaved boost converter and the minimization of current overshoot are obtained using a hysteresis control with proposed incremental duty control (IDC) method. The output voltage of the converter is 400V and two-phase boost converters operated at continuous conduction mode (CCM) are used to build the IBC. Experiment results from a 1kW prototype are presented an improvement of the system efficiency in a wide power range.
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