Investigation and validation of solar photovoltaic-fed modular multilevel inverter for marine water-pumping applications

This article discussed the development of a solar photovoltaic-fed modular multilevel inverter (MMI) with reduced switch count to operate an asynchronous motor drive for maritime applications. The proposed marine water-pumping system consist of a PV panel, an asynchronous motor drive, and modular inverter. The suggested topology can produce 11 levels of output using asymmetric DC sources. The proposed MMI consists of five DC sources, and they are powered by the PV panels. The primary advantage of the proposed topology is that it does not need any auxiliary circuit to produce the negative levels. Moreover, the active sources (PV panels) in the proposed system are reduced by implementing a modified single-input and multiple-output SEPIC converter. The power consumption by on-board pumping systems in maritime is estimated to be almost 50% of the total power. Taking this into account, this article investigates an adaptive fuzzy logic-based closed-loop control design for reducing the losses in the induction machine and thereby improving the efficiency of the system. Further, the performance of the proposed system is compared with the conventional PI controller, and from the results, it is proved that the proposed control system works effectively in reducing the losses as well as improving the efficiency of the system. The simulations are carried out in MATLAB/Simulink, and the experimental investigations are carried out in the laboratory. The obtained experimental results are similar to the simulation results.