Modelling and Post-Fault Current Control Strategy for Multi-Three-Phase Machines

The growing development of Multi-Three-Phase Machines (MTPM) as competitive to conventional three-phase machines has attracted more attention to the higher reliability and fault-tolerant capability of the electrical drives system especially for safety-critical applications. In this paper, modelling technique and post-fault current control strategy for dual three-phase Interior Permanent Magnet (IPM) synchronous machines are presented, utilizing the Vector Space Decomposition (VSD) algorithm. As the multi-stator (MS) or dq modelling is an ideal option for post-fault strategies, the comparative study between VSD and MS methods are demonstrated in order to analyse their dynamic performance in nominal and faulty conditions. This take into account the equivalent harmonic inductance variation, which is then used to introduce the postfault control strategy. A double three-phase IPM machine is modelled and operated in two different operating conditions: nominal and one three-phase set of windings in open-circuit (OC). In OC fault, the proportional and integral (PI) controllers are re-designed while adapting the inductance variation. The current dynamics responses are analysed in both healthy and faulty conditions by means of Matlab/Simulink ® simulations.