Research On High Quality Control Technology Of Dual-three-phase PMSM

With the continuous application and development of the electric drive systems to the high-end field,higher and higher requirements are put forward for the quality characteristics of the machine.The development of three-phase machine is limited in the field of high-reliability and high-power drive systems such as electric vehicles,while the multi-phase machine have been paid more attention due to the advantages such as better fault tolerance and lower voltage and high power.In order to improve the quality characteristics,this paper studies the control theories and methods such as harmonic current suppression,torque ripple suppression,fault diagnosis and fault tolerance for the dual-three-phase permanent magnet synchronous motor.In order to solve the problems of harmonics and efficiency,studying a method for harmonic current suppression based on second rotation coordinate transformation combined with the PIR controller.Based on the unified PIR control idea,established the simulation model for suppressing harmonic currents that uses the second rotation coordinate transformation combined with the advantages of the PIR controller.Calculating the efficiency of the machine after suppressing the harmonic currents,the harmonic content of the current is suppressed significantly,and the efficiency of the machine can be increased by 0.375-0.535%.In order to solve the problems of current sensor faults,studying a fault diagnosis method based on harmonic plane current trajectory.By establishing coordinate system with different axis orientation,the results of fault eigenvalue compared with threshold value is defined as the diagnosis basis.For fault tolerance,using the remaining phase windings currents substituted fault current by deriving physical constraints between the windings of DTP-PMSM,and this method is suitable for both one-phase and two-phase open faults.Establishing the current sensor active fault-tolerant control system of DTP-PMSM,and simulation and experiment verified the timeliness of the diagnostic method and the validity of the fault-tolerant method.In order to solve the problems of phase open fault,studying a one-phase open fault diagnosis method based on harmonic plane current trajectory is proposed.Similar to current sensor diagnostics,the vertical component of the current trajectory is defined as the fault characteristic value by calculating theoretical value,and then compared with the threshold value as the diagnosis basis for whether the fault occurs.Based on the equivalent mathematical model of harmonic plane injection current to solve the traditional fault tolerance method is poor in universality and too dependent on the accuracy of the fault mathematical model,the fault-tolerant methods of one-phase and two-phase open are analyzed.In two-phase open faults,theoretical derivations are made for the fault in one set of windings,the fault in the two sets of windings difference by 90°,the fault in the two sets of windings difference by 30°,and the fault in the two sets of windings difference by150°;Establishing the phase open active fault-tolerant control system of DTP-PMSM,and simulation and experiment verified the timeliness of the diagnostic method and the validity of the fault-tolerant method.In order to solve the problem of electromagnetic torque superimposed secondary torque ripple after one-phase open fault,studying a method of torque suppression strategy based on harmonic plane injected current plus quasi PR control was proposed.And deducing the mechanism of equivalence fault mathematical model based on harmonic plane injection in detail.On this basis,a quasi-PR controller is used to suppress the secondary ripple component of torque superposition,this method not only suppresses the secondary torque ripple well,but also is compatible with the fault-tolerant algorithm,which makes the algorithm simple and universal.