Hierarchical Model-Based Fault Diagnosis for an Electrical Power Generation Storage Automotive System

This paper deals with the design and validation, through simulation in a Matlab/Simulink environment, of a high-level model-based diagnostic algorithm for an automotive electric-power generation storage system (EPGS). The EPGS includes and alternator with rectifier, a battery and a voltage regulator. Mathematical models of these subsystems, based on the physics of the processes involved, consist of time-varying nonlinear ODEs. The diagnostic problem is approached in hierarchical fashion, and this paper focuses on a high-level (supervisory) diagnosis aimed at distinguishing between faults in the alternator and battery subsystems. The proposed diagnostic approach is based on the generation of residuals using system models and through comparison of the predicted and measured value of selected variables, including alternator output current, field voltage, battery current, battery voltage and engine speed. This paper outlines the development of a high-level model of the EPGS system, a high-level diagnostic algorithm and simulation results.