CHB inverter with DC-link capacitor balancing and total harmonic minimization

A cascaded H-bridge (CHB) multilevel inverter generally requires several DC sources. An alternative option is to replace the separate DC source feeding an H-bridge cell with a capacitor, while maintaining the other H-bridge cell with a real DC voltage source. In this paper a 7-level cascaded H-bridge inverter with a single DC-source is presented. This paper focuses mainly to achieve effective capacitor voltage balancing and selective harmonic elimination (SHE) based on the Newton Raphson algorithm (N–R). It shows hope to reduce the voltage ripple of the capacitors, which leads to higher power conversion efficiency with equal power distribution, reduces the initial cost, and complexity hence it is apt for industrial applications. Simulation results support the proposed control technique.