Novel Technique for Reduction in Switching Stress of a PV Source Fed Boost Converter

The energy available from PV Source is completely volatile in nature at different interval of time in a day, as it is dependent upon the local temperature and irradiation upon the PV cell. So the researchers try to utilize various techniques to extract the maximum power during this solar time. Out of various techniques developed by the researchers, the most common technique available is the MPPT (Maximum Power Point Technique) technique. Since the available voltage/ current across the PV unit varies with time in a day, so it is necessary to feed this energy to dc grid in optimum way. It is obvious that a dc-dc converter, which will act between PV source and dc grid, operates at a regulated dc voltage. So the dc-dc converters to be used are boost /buck-boost type. In current literature, it is proposed a boost converter with modified parameters so that it would operate with reduced losses than its conventional one. In conventional one, the switch carries two currents during turn-on. One is short-circuit current through source inductor as the switch is connected across the dc link and other one is discharging current of snubber capacitor. So with proper designing of filter, the effect of first one, which is major contributor of switching loss, is eliminated. So the turn-on losses, which is only due to discharging snubber capacitor, is minimized and the turn-off loss is also minimized by the snubber capacitor connected in series with diode. Though this mechanism is referred to partial soft-switching, but it operates very close to soft-switching. The modified technique for boost converter is proposed and the mathematical model is developed to simulate with the help of MATLAB/Simulink to justify the said purposes.