Frequency-Dependent Evaluation of the Voltage Stability in Vehicular Power Systems

Fail-safe vehicular power systems and proper operation of safety-critical components are fundamental requirements for automated driving functions. On the other hand, the vehicular power system is getting more susceptible to disturbances. In addition, due to overlapping interferences it is increasingly difficult to determine causes of individual disturbances. Therefore, a methodology is shown for splitting superimposed disturbances by means of suitable filtering and evaluation of the voltage stability of each filtered signal. The evaluation is based on moving averaging of the filtered voltage signals over frequency-dependent time intervals. The relative frequency distribution of the averaged voltages and their position regarding to frequency-dependent voltage time limits yield stability parameters, which show the individual effect of disturbances with different frequencies on the overall voltage stability.