Cascaded Fuzzy Logic Controlled Modular Multilevel Converter for PV Based DSTATCOM Applications

This paper analyses the implementation of modular multi level converter (MMLC) in the application of grid connected Photovoltaic system in an efficient manner. As MMLC exhibits properties of high modularity and scalability, it is highly suitable for the high power applications, which makes MMLC to be preferred in this study as an apt replacement of the conventional DC–DC converters. A unified control using a cascaded fuzzy logic controller (CFLC) is proposed for both the maximum power point tracking and modular 7 level converter (M7LC) control. The CFLC is analogized with the conventional PI and Fuzzy controllers under both the normal and partial shaded conditions. The entire system is assessed with the aid of using MATLAB simulation. The observed outcomes exhibit that total harmonic distortion (THD) of line current is minimum under all operating conditions when the CFLC is used for M7LC. The prototype of the proposed M7LC with CFLC is implemented in FPGA SPARTAN 6E controller for the experimental validation. The proposed approach delivers lesser THD of 1.02% under normal condition and 1.12% under partial shading condition.