A Comparative Analysis of Modulation Control Strategies for Cascade H-Bridge 11-Level Inverter

The range of the output power is a very important and evident limitation of two-level inverters. In order to overcome this disadvantage, multilevel inverters are introduced. Recently, Cascade H-Bridge inverters have emerged as one of the popular converter topologies used in numerous industrial applications. The modulation switching strategies such as phase shifted carrier based Pulse Width Modulation (PWM) technique and Stair case modulation with Selective Harmonic Elimination (SHE) PWM technique are generally used. NR method is used to solve highly non linear transcendental equations which are formed by SHEPWM method. Generally NR method has a drawback of requiring good initial guess but in this paper a new approach is implemented for NR method with any random initial guess. A three phase CHB 11-level inverter is chosen for analysis. MATLAB/SIMULINK programming environment and harmonic profiles are compared. Finally this paper presents a method at fundamental switching frequency with least % THDV.

• Joshi Manohar. V.
• Sujatha. P.
• Anjaneyulu K. S. R

• Cascade H-bridge 11- level Inverter
• NR method
• Phase shifted carrier based pulse width modulation (PSCPWM)
• Selective Harmonic Elimination Pulse Width Modulation (SHEPWM)
• Total Harmonic Distortion (%THDv).

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