Active attenuation of electromagnetic noise in an inverter-fed automotive electric drive system

Electromagnetic noise, typical for systems with switching power converters, is especially troublesome in automotive electric drive systems because of the multitude of sensitive electronic equipment onboard of modern cars. To satisfy the relevant engineering norms, passive radio-frequency (RF) filters must be installed in the power electronic part of a drive. The RF filters add to the cost and size of the drive, which car designers strive to minimize to increase the passenger space. In this paper, active attenuation of the electromagnetic noise by means of the so-called random-delay pulse width modulation is described in application to an inverter-fed automotive ac drive. Based on computer simulations and experimental investigation, this simple and inexpensive method is shown to be highly effective