Patent ID: 8582262
Filing Date: 2013-11-12
Classification: H02H

Abstract:
1. A method for reducing inrush current to an electrical load in response to detection of a disturbance occurring in an input AC power supply coupled to the electrical load, comprising: applying an input voltage to the electrical load; monitoring the current drawn by the load; recording peak values of the current drawn by the load; continuously monitoring the voltage of the input AC power supply to detect a voltage sag to a predetermined level below rated voltage for short periods of time of one half cycle or more indicating a disturbance in the input AC power supply that would cause an inrush current to the electrical load upon ending of the disturbance; in response to detection of the voltage sag, recording a peak current limit reference (I detecting when the current level exceeds the peak current limit reference (I adding an impedance to the electrical load in response to detecting the disturbance, wherein an inrush current to the electrical load is limited as the input voltage returns to a normal operating level voltage.