CLOSED LOOP CONTROL OF HIGH STEP UP CONVERTER WITH FOCUS ON PHOTOVOLTAIC SYSTEMS

The high step-up converter is inevitable in a photovoltaic system since it requires a sufficiently high step-up conversion. A high step up converter with coupled inductors could be used for this purpose due to its inherent advantages. It acts as an efficient interface between the PV system and the grid. The output obtained in such a system is found to be fluctuating with load variations. This could escalate numerous issues in the quality of output. A closed loop voltage mode control would be useful in disentangling this issue. The closed loop control is achieved by making use of a PIC microcontroller. The output of the converter is fed to the controller which in turn generates gate pulses to control the two MOSFET switches. The controller varies the duty ratio of the system in accordance to the fluctuations in the load voltage. Also the system is found to be effective while working in high input as well as low input conditions making it efficient during night time and also on rainy days. This study of a high step-up converter can inculcate a confidence that these researches can definitely bring about a revolution in the energy scenario of today.