Method for state-of-health monitoring in electric vehicle drive systems and components

A system for state-of-health monitoring of a powertrain component in an electric vehicle system, comprising:

• a processor;
• and
• a memory including instructions that, when executed by the processor, cause the processor to:
• determine an equivalent circuit model of the powertrain component;
• determine an estimate of heat losses in the powertrain component considering both transient and steady-state conditions;
• determine an estimate of heat flow through the powertrain component based on one or more material properties of the powertrain component;
• determine, based on the estimate of the heat flow through the powertrain component, a temperature of a particular structure within the powertrain component;
• and
• determine, using a Rainflow algorithm, a number of temperature cycles until failure of the particular structure based on the temperature of the particular structure.