Simulation of arbitrary fault-conditions in PM-machines by generalized unsymmetrical modeling

Nowadays, fault tolerance and reliability in electrical machines have become additional important design features besides functionality and efficiency. However, fault tolerant design often comes along with more space requirement and cost, which is not acceptable in many industrial applications. It is rather desirable to have standard machines working also in safety relevant applications and providing fault tolerance by sophisticated control methods. However, these require a detailed knowledge of the dynamic machine behavior in case a failure occurs and the electric and magnetic conditions are no longer symmetrical. Moreover, restoring of feasible operation conditions can also necessitate unsymmetrical voltage supply of the machine. In this paper, the commonly known modeling approaches of symmetrical machines during healthy operation and symmetrical voltage supply are extensively generalized. A general model for PM-machines with arbitrary fault injection capability and unsymmetrical voltage supply and machine operation conditions is set up and evaluated for different important machine faults.