Functional monitoring of electric vehicle propulsion system - using actual instantaneous system power input which is compared with theoretical value under same conditions to detect malfunction

摘要

Battery (1) voltage (U) and current (I) measurements, discounting non-propulsive loads, give the actual instantaneous power. The theoretical power is the sum of inverter (2) and induction motor (3) losses and the power (set torque x angular velocity) delivered to the final drive (4). Set torque is determined by the driver through accelerator (8) and brake (9) pedal positions, transmitted by sensors (6,7) to the controller (5). Losses, tabulated from bench tests as functions of torque and speed, are obtained from memories by a calculating unit in the controller, which uses them, with operational parameters to compare the two power values. An excessive discrepancy initiates an alarm. ADVANTAGE - Standard vehicle instrumentation provides all measurements required.