Modelling and Fault-Tolerant Control of Triple Three-Phase PMSM under Open-Phase Fault with Minimum Stator Power Losses

In this paper, a complete model of faulty multiphase permanent magnet synchronous machines (PMSMs) is presented in phase domain when the machine is fed by voltage-source inverters (VSIs). The presented model is helpful for implementing the simulation model of the machine when it is supplied by voltage inputs. Then, an orthogonal fault-specific transformation matrix is introduced to acquire the machine model in vector-space decomposition (VSD) domain. This model is helpful in the sense that it establishes mathematic relations between the stationary components of machine currents in multi-star (MS) and VSD domains. Based on these relations and along with transformation of VSD components to synchronous and anti-synchronous reference frames, a current sharing strategy is obtained to distinguish the contribution of each three phase winding set to the developed torque under faulty conditions. The reference values in VSD domain are set so that the lowest ohmic losses are dissipated under faulty conditions.