Abstract: A method of operating a power converter for exchanging power with an alternating current (AC) grid includes: commanding one or more switches to selectively conduct a current between a DC storage device and the AC grid via a series combination of a resistor and an inductor; measuring a current through the series combination of the resistor and the inductor; and determining, based on the measured current, an estimated grid voltage of the AC grid. The one or more switches are commanded based on the estimated grid voltage. The power converter is operated in each of: a pre-synchronous mode before energy is exchanged between the DC storage device and the AC grid, and a post-synchronous mode while energy is exchanged between the DC storage device and the AC grid. Different techniques are used to determine the estimated grid voltage in the pre-synchronous mode and in the post-synchronous mode.

Abstract: A method for state-of-health monitoring of a powertrain component in an electric vehicle system includes: determining an equivalent circuit model of the powertrain component; modeling heat losses in the powertrain component considering both transient and steady-state conditions; modeling heat flow through the powertrain component based on one or more material properties of the powertrain component; determining a temperature of a particular structure within the powertrain component; and determining, using a Rainflow algorithm, a number of temperature cycles until failure of the particular structure based on the temperature of the particular structure.