Faults in hybrid electric vehicles' permanent magnet machines

Nowadays, automobile transportation is in a crisis due to the high price of gasoline and, in the future, the crises will worsen unprecedentedly. Hence, researches are oriented toward hybrid electric vehicles being a good alternative of conventional vehicles. Thus, assuring the health and proper operation of HEVs is a mission. This paper focus on the importance of HEV's permanent magnet machine fault identification where a survey of the different types of fault that may arise is illustrated, relating it to the useful parameters that should be measured and checked to detect the presence of each type of fault. The faults are classified according to their level of severity; a case study is conducted where it is shown that demagnetization of magnet is the most sever fault taking into consideration the relative cost of magnet and the occurrence percentage of demagnetization.