S.G.  Srivani, V.S.  Kirthika Devi, O.C.  Remya, 
    Performance Analysis of Single Phase Closed Loop System for Cascaded
H-Bridge Multilevel Inverter Using Renewable Source,
    Journal of Engineering and Applied Sciences,
    Volume 13,Issue 7,
    2018,
    Pages 1757-1766,
    ISSN 1816-949x,
    jeasci.2018.1757.1766,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2018.1757.1766)
    Abstract: This study presents a closed loop "Synchronous Reference Frame" (SRF) control method using
seven level cascaded H-bridge multilevel inverter for a single phase grid connected photovoltaic system. The
proposed control scheme is obtained in order to inject quality current to the grid connected system. This
method can generate the sinusoidal current which reduces the total harmonic distortion. The control strategy
allows independent control of each DC-link voltage. In addition, it tracks the maximum power point of PV
strings. The simulation results for seven level CHB-MLI for 555 W/230 V/50 Hz is presented to validate the
proposed control scheme. Simulation is done using MATLAB Simulink platform.
    Keywords: cascaded H-bridge multilevel inverter;DC link capacitor; boost converter;Maximum Power Point Tracking (MPPT);Photo Voltaic (PV);PI controller;Synchronous Reference Frame (SRF)