LEAKAGE DETECTION CIRCUIT WITH INTEGRAL CIRCUIT ROBUSTNESS CHECK

摘要

An electrical leakage detection circuit detects electrical leakage of a battery in an electric vehicle. A first transistor switch coupled between a first and second resistor is actuated for coupling the first resistor and the second resistor. A second transistor switch coupled between a third and fourth resistor is actuated for electrically coupling the third and fourth resistor. A controller generates control signals for actuation of the first transistor switch and the second transistor switch. A first voltage is measured across the traction battery cell string. A second voltage is measured across the second resistor. A third voltage is measured across the third resistor. The controller detects electrical leakage by measuring the first, second, and third voltages and applying them in equations utilizing these voltages with constants of the first, second, third, and fourth resistances.

主权项

1. An electrical leakage detection circuit detecting electrical leaks in a traction battery cell string in an electric vehicle a high voltage domain galvanically isolated from a low voltage domain, comprising:
first, second, third, and fourth resistors coupled between a positive terminal of the cell string and a negative terminal of the cell string; a chassis ground coupled between the second and third resistors; a first transistor switch selectively actuatable for electrically coupling the first and second resistors; a second transistor switch selectively actuatable for electrically coupling the third and fourth resistors; and a controller controlling actuation of the first and second transistor switches; wherein the first and second transistor switches are actuated to selected positions, a first voltage is measured across the cell string, a second voltage is measured across the second resistor, a third voltage is measured across the third resistor, the controller detects electrical leakage as a function of the first voltage, at least two of the resistors, and at least one of the second voltage and the third voltage.