Implementation of Super Lift Luo Multilevel Inverters Suitable for PV Interfacing

Among the renewable energy conversion techniques, photovoltaic (PV) energy conversion is attractive due to its lifetime, less maintenance and easy conversion. PV technology directly converts sunlight into dc electricity. The output needs to be boosted up (lifted) to feed the loads. The most notable development in recent years for dc/dc and dc/ac conversions is the super lift technique. In this paper, super lift Luo Multilevel inverters (SLL-MLI) are used to boost up the voltage as well convert the lifted dc into ac. This acts as a single stage power conditioning unit (PCU) for PV applications with better power quality. In conventional MLI, as the number of levels varies, the harmonic content degrades, which relies on the type of PWM and number of switches used. In the super lift inverter, the lesser harmonics can be obtained with reduced number of levels and switches with conventional sine PWM. MatLab/Simulink software has been used in this paper to model 7 and 15 level super lift inverters with a transfer gain of 4.