This paper describes a new methodology and application case to determine quantitatively the transition probabilities for multi-state Markov models of the fault tolerant safety-critical drives of electric vehicles. The results of the study allow determining the transition probabilities for the multi-state system Markov models of the fault tolerance, considering real operational conditions of an electric traction drive. The investigation and discussion of fault tolerance of the traction drive of an electrical helicopter serve as application case. The proposed methodology can generally be used for the assessment of fault tolerance of safety-critical systems in compliance with the requirements of the project.
This paper deals with fault tolerant multiphase electrical drives. The quality of the torque of a vector-controlled Permanent Magnet (PM) Synchronous Machine supplied by a multi-leg Voltage Source Inverter (VSI) is examined in normal operation and when one or two phases are open-circuited. It is then deduced that a seven-phase machine is a good compromise allowing high torque-to-volume density and easy control with smooth torque in fault operation. Experimental results confirm the predicted characteristics.
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.