This paper proposes a novel scheme for the identification of the whole flux linkage map of permanent magnet synchronous machines, by which the map of dq-axis flux linkages at different load or saturation conditions can be identified by the minimization of a proposed estimation model. The proposed method works on a conventional three-phase inverter based vector control system and the immune clonal based quantum genetic algorithm is employed for the global searching of minimal point. Besides, it is also noteworthy that the influence of uncertain inverter nonlinearity and circuit resistance are cancelled during the modeling process. The proposed method is subsequently tested on two PMSMs and shows quite good performance compared with the finite element prediction results.

Reliability of electric drives is of paramount importance for safety critical applications in transportation, medical and military industries. While numerous fault tolerant machine and inverter topologies have been developed for improving drive reliability, comprehensive reliability evaluation of fault tolerant electric drive systems has not been reported in literature. This paper performs quantitative assessment of mean-time-to-failure of representative fault tolerant permanent magnet AC drive systems by employing Markov chain modelling technique. It is shown that the mean-time-to-failure of a fault-tolerant drive can be significantly increased by employing health monitoring/maintenance check and prompt repair/replacement of faulty components.

This paper reviews the relative merits of induction, switched reluctance, and permanent-magnet (PM) brushless machines and drives for application in electric, hybrid, and fuel cell vehicles, with particular emphasis on PM brushless machines. The basic operational characteristics and design requirements, viz. a high torque/power density, high efficiency over a wide operating range, and a high maximum speed capability, as well as the latest developments, are described. Permanent-magnet brushless dc and ac machines and drives are compared in terms of their constant torque and constant power capabilities, and various PM machine topologies and their performance are reviewed. Finally, methods for enhancing the PM excitation torque and reluctance torque components and, thereby, improving the torque and power capability, are described