Power System Switching Transients in Passenger Automobiles

Design of automobiles has already reached to a level that many uses highly complex and sophisticated computing applications with associated electronics. These high-ended car electronic automation systems require very accurate and steady supply and most of these sensitive car electronics like multimedia systems, navigation units, etc., prone to fail in the presence of transient over voltages through the DC supply lines. Therefore a measurement of transients in automobiles and analysis has been done in order to identify the characteristics and risk levels of such transients for the vehicular control and attendant systems. In evaluating, an extensive survey of the transients carried out at a constant location within the electrical system of many late model automobiles. Transients were measured, rise times ranging from 0.3 mu s to 700 mu s and pulse durations from few microseconds to hundreds. There are bursts spread over milliseconds while number of transients have rise and fall times (< 5 ns) in the RF range (> 200 MHz). Thus the transient waveforms were first categorized to arrive at a compact set of common types of waveforms and analyzed. The measured transient parameters were compared with the sensitivity of several standard car electronic devices to identify their immunity to the conducted transients. Providing an overview of how to mitigate or reduce the effect of transients in automobiles in order to increase the power system efficiency and reliability, also expected while addressing the sensitivity of devices.