Transformerless cascaded inverter topology for photovoltaic applications

Cascaded Multilevel inverter for photovoltaic generating system is presented in this paper. In photovoltaic generating (PV) system, it is normal practice to use an inverter-transformer combination to convert the low voltage DC power output of the PV modules into AC power of required voltage and frequency. In this paper, an attempt has been made to study the performance of PV system with multilevel inverter (MLI) topology, which eliminates the need for transformer. The performance of the cascaded MLI with fundamental switching scheme for different levels is studied through simulation. A Mathematical model of the PV system is also developed and integrated with the MLI model. The overall system performance is studied for different solar intensities. A prototype PV system with 5-level MLI is implemented in hardware to validate the simulation results.