Selective harmonic elimination pulse width modulation for five-level cascaded inverter

This paper presents an efficient selective harmonics elimination method for a five-level cascaded inverter by using the Newton-Raphson method. The aim of this project is to eliminate selected low-order harmonics by solving non-linear equations using the programming developed based on NewtonRaphson method. Meanwhile, at the same time, the fundamental component is retained efficiently. Instead of single switching, multiple switching in quarter cycles has been introduced to increase the number of harmonic orders that should be eliminated. In addition, the low-order harmonics up to the 5th order for single switching and 17th order for multiple switching are eliminated from the inverter output voltage waveform for entire modulation index. The calculated switching angles have been inserted into the simulation model of the five-level inverter by using PSIM software. Moreover, the calculated switching angles for single and multiple switching are then tested by using a prototype of a five-level inverter that has been built in the laboratory. The simulation results are verified with the experimental results for single and multiple switching