×

Isolation monitoring system and method utilizing a variable emulated inductance

  • US 8,598,897 B2
  • Filed: 01/24/2011
  • Issued: 12/03/2013
  • Est. Priority Date: 01/26/2010
  • Status: Active Grant
First Claim
Patent Images

1. A system for measuring a leakage resistance between a high voltage (HV) system of a vehicle and a vehicle chassis, comprising:

  • an emulated inductance that is connected between the HV system and the vehicle chassis and that has an inductive reactance that substantially cancels a capacitive reactance between the HV system and the vehicle chassis, wherein the emulated inductance includes a variable resistance;

    a signal source that outputs one of an AC current signal and an AC voltage signal between the HV system and the vehicle chassis;

    a sensor that measures one of;

    an AC current response to the AC voltage signal between the HV system and the vehicle chassis; and

    an AC voltage response to the AC current signal between the HV system and the vehicle chassis; and

    a control module that varies the variable resistance over a range of values, identifies one of the values of the variable resistance that corresponds to a peak voltage associated with the emulated inductance, sets the variable resistance to the one of the values, and calculates the leakage resistance based on the one of the AC current response and the AC voltage response while the variable resistance is set to the one of the values.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×