A novel Fourier series time function for modeling and simulation of PWM

In this paper, a novel time function, called a modulated Fourier series (MFS), is presented for accurate modeling and rapid simulation of natural sampled pulsewidth modulated (PWM) systems in power electronic applications. This analytical technique eliminates the necessity for an iterative search, employed in currently available simulation packages, of modulated pulse edge transitions during accurate PWM waveform simulation. PWM simulation results are presented for MFS model validation, which are indistinguishable from those for an analog comparator modulator employing arbitrary nonperiodic signals. Additional simulation traces are presented of the fidelity with which the MFS accurately replicates, with only two carrier harmonics, the effects of PWM inverter switching on motor drive current as high-frequency harmonic ripple when compared with experimental test data. Substantial savings of up to fiftyfold in motor drive simulation time are presented without loss of simulation accuracy.