Current harmonics of voltage-source active rectifier with random switching frequency

This paper presents the issue of current harmonics drawn from the grid by three-phase voltage-source active rectifiers when the switching frequency of the devices is random; it is not an integer multiple of the supply frequency (50 Hz). The first part compares the harmonic analysis calculations derived for the piecewise linearized simplified current waveform and the simulations in the random frequency case. The second part presents a comparison of the current harmonic analysis when the switching frequency is the integer multiple of the supply frequency and when it is not. The second part also shows a dependence of the current spectrums on the random switching frequencies. This paper verifies, that the same conclusions of the previous publications apply to both the switching frequency that is the integer multiple of the supply frequency and the random switching frequency.