BATTERY CELL VOLTAGE SENSING CIRCUIT DIAGNOSTICS

摘要

A system and method are disclosed for diagnosing an open circuit of a cell voltage sensing board. The board includes, for each cell, a line balancing resistor, a line sense resistor, and a gate. Each gate connects and disconnects a given line balancing resistor to and from a corresponding cell. A cell voltage is measured for a selected battery cell, and a controller determines if the selected battery cell is an uppermost or lowermost cell in the battery stack. A line sense resistance value is calculated for the selected battery cell using a first set of equations when the selected battery cell is the uppermost cell, a second set of equations when the selected battery cell is the lowermost cell, and a third set of equations when the selected battery cell is neither. A control action is executed when the calculated line sense resistance exceeds a calibrated resistance threshold.

主权项

1. A method of diagnosing a cell voltage sensing board, the method comprising:
connecting the cell voltage sensing board to a plurality of battery cells of a battery stack, wherein the cell voltage sensing board includes, for each of the battery cells, a line balancing resistor, a sense line resistor, and a gate that connects and disconnects the line balancing resistor from a corresponding one of the battery cells; measuring a cell voltage via the cell voltage sensing board for a selected battery cell of the plurality of battery cells; determining if the selected battery cell is an uppermost cell or a lowermost cell in the battery stack; calculating a line sense resistance value for the selected battery cell via a controller using a first set of equations when the selected battery cell is the uppermost cell, using a second set of equations when the selected battery cell is the lowermost cell, and via a third set of equations when the selected battery cell is neither the uppermost cell nor the lowermost cell; comparing the calculated line sense resistance value to a calibrated resistance threshold via the controller; and executing a control action with respect to the cell voltage sensing board when the calculated line sense resistance value exceeds the calibrated resistance threshold.