Harmonic elimination in pulse-width modulated inverters using piecewise constant orthogonal functions

A new method is presented for selective harmonic elimination in pulse-width modulated (PWM) inverter waveforms by the use of piecewise constant orthogonal functions. The block-pulse functions are first applied and the relationships between these functions with Walsh functions and Fourier series are used for harmonics elimination in a PWM inverter. The set of systems of linear equations obtained replaces the system of nonlinear transcendental equations used in the Fourier analysis approach. As compared with the Walsh domain technique, the present algorithm reduces the number of combinations for the case where more than one angle is allowed to vary within a given interval.