Research On Model Predictive Control For Primary Permanent Magnet Linear Motor

High-reliable motor drives are important for rail transit and industrial production.Hence,fault-tolerant controls of motor drives have attracted much attentions to cope with sensor faults,power device faults and so on.In this thesis,fault-tolerant controls of component failures are investigated for the primary permanent-magnet linear motor drive.(1)Model predictive control under failure mode of voltage sensor.A fault-tolerant control scheme for voltage sensor fault is proposed,in which the measured dc bus voltage is replaced by rated values.The distributions of first-,second-and third-optimal voltage vectors(VVs)with positive and negative voltage errors are curved in this thesis,respectively.According to experimental results,FCS-MPCC can perform well under large voltage error(±33.3% of rated value),which shows the strong robustness for voltage error.(2)Model predictive control under failure mode of current sensor.A dual-vector located model predictive control(DV-MPC)with single dc bus current sensor is proposed to cope with phase current sensor faults.According to the direct measurement and delay measurement of the dc bus current,the phase currents can be well reconstructed.The sunk time is defined to evaluate the reconstruction accuracy.Based on the fast vector location,the first-and secondoptimal VVs are determined simultaneously.In order to avoid that only one phase current can be updated for a long time,a second-optimal VV replacement principle is proposed.Compared with FCS-MPCC,DV-MPC shows better steady-state,starting and current response performances,which have been verified by experimental results.(3)Model predictive control under failure mode of power device.Once one leg fails,the dual-mover drive system is feed by a five-leg voltage-source-inverter(VSI).To reduce the computation burden of FCS-MPCC,a dual-level located MPC(DL-MPC)is proposed for the five-leg dual-mover drive system.Firstly,the two first-optimal VVs for both movers are determined by fast vector location in the mover level.Secondly,different cases are discussed according to different conditions in the system level.According to the theoretical analysis,both FCS-MPCC and DL-MPC will select same VVs under same operation conditions,that is,they are completely equivalent.Due to existence of the dual-level location,however,the computation burden of DL-MPC is only 22% of that of FCS-MPCC.(4)Based on d SAPCE DS1103 controller,the hardware and software facilities of PPMLM drive system is designed and the feasibility of fault-tolerant control schemes are verified.