Research On Fault-tolerant Control And Harmonic Suppression Of No-phase-shifting Dual Three-phase PMSM

The multiphase permanent magnet synchronous motor has the advantages of low voltage,high power and high fault tolerant abilities,compared with the traditional three-phase permanent magnet synchronous motor.In recent years,it has been widely used in the high power and high reliability fields such as wind power generation and electric propulsion.The dual three-phase permanent magnet synchronous motor(DTP-PMSM)is one of the widely used multiphase motor.There are two sets of three-phase armature windings in this motor.In this paper,the fault tolerant strategy of the DTP-PMSM without phase shift between two sets of windings is researched.The mathematical model and harmonic suppression methods of this motor are also built and proposed.Firstly,the two sets of windings are treated independently and the mathematical model based on independent current control is established.Meanwhile,the mathematical model of DTP-PMSM is established according to the vector space decomposition method.By comparing the two models,the latter one that can be used in the open-circuit fault is applied in this paper.When the single-or two-phase open-circuit fault occurs,the currents in this motor have obvious second harmonic component.Therefore,the mathematical models under faulty conditions are built,and the harmonic components are also analyzed.The current second harmonic is caused by the unbalance of the self-inductance and mutual inductance under opencircuit faulty conditions.Then,a fault-tolerant control strategy for DTP-PMSM without phase shifting is proposed,where a feedforward compensation controller and a resonant controller are used to suppress the second harmonic.The resonant controller has higher robustness,so it has more advantages than the feedforward compensation under single-and two-phase faults.The parameters of the resonant controller keep unchanged even the faulty phase is different,which simplifies the harmonic suppression method.The resonant controller obtains a better harmonic suppression effect with inaccurate inductance parameters.Finally,the fault-tolerant control strategy is verified on a no-phase-shifting DTP-PMSM hardware experimental platform.