Simulation and Analysis of Control and Modulation Schemes for a Multilevel Cascaded H-Bridge Inverter for use in a Battery Energy Storage System

Progress in efficiency improvement has been main a matter in grid tie inverters. The employment of multilevel inverters in energy conversion promises a better power quality and lower switching losses than ordinary two-level inverters even in low voltage grid. This paper presents the implementation of several control schemes (Vector Oriented Control, Hysteresis Control) and modulation techniques (Pulse-width Modulation, Nearest Level Control) for a 17 level cascaded H-bridge grid tie inverter for a battery energy storage system. For this purpose, the different physical models distinguished in control and modulation schemes were implemented in Simulink (R) and Simscape (TM). On the merits of simulations it is concluded, that the phase shifted modulation technique gives less total harmonic distortion in current and the nearest level control gives lower switching losses when compared to other studied techniques in strong and weak grid tie inverters.