Using resistance equivalent to estimate heater temperature of an exhaust gas after-treatment component

摘要

A method comprises measuring a voltage drop across, and the current passing through, a catalyst heater 110, and generating a voltage equivalent resistance by dividing the voltage by the current. The voltage equivalent resistance is used to estimate, and therefore to control, the temperature of the heater. The voltage drop may be measured using a pair of Kelvin connections 104. The current may be measured using a current sense resistor 122. The resistance may be compared to a reference to value to generate a temperature rise value. The heater may be turned off when the temperature rise value indicates that the heater is hotter than a threshold temperature.