Research On Fault Tolerant Control Strategy For Dual Three Phase Permanent Magnet Synchronous Motor

With the high power and high reliability of the AC motor,the Dual Three-phase PMSM is emerging.The advantages of high efficiency,low loss,low EMF harmonic,smooth torque ripple and strong fault tolerant operation ability having made it widely used in ship propulsion,all electric aircraft and so on.The multiphase motor represented by Dual-Three phase PMSM is one of the main development directions of the AC drive system.In this paper,the mathematical modeling,harmonic current suppression and fault-tolerant control strategy for Dual-Three phase PMSM are analyzed.In this paper,the mathematical model of the Dual Three-phase PMSM in the six-phase stationary coordinate system is carried out by the method of double d-q transformation and the vector space decomposition transformation.And the equivalent circuit is set up to analyze the model.Aiming at the omitting the harmonic current,this paper establishes a vector control scheme using improved PR regulators.The rotation coordinate transformation is omitted and the motor current is directly controlled in the two-phase stationary coordinate system.This paper analyzes the fault-tolerant control scheme based on the current hysteresis comparison control technology after the motor has a fault of stator winding open-circuit.According to the two basic principles of the constant output power and the unchanged of rotating magnetic force,the expression of motor current is obtained.And a fault tolerant control system using hysteresis control technology is established.At the same time,the current and the torque response of the fault tolerant control system are simulated and analyzed.The rotating magnetic force and output torque of the Dual-Three phase PMSM under the fault of open phase are analyzed,and the two-order torque ripple is obtained.Based on vector space decomposition theory,the Dual-Three phase PMSM after the open fault of phase W is modeled and the performance of the traditional vector-controlled scheme is analyzed.Based on the mathematical model after the phase absence,a fault tolerant control scheme using quadratic transformation is analyzed,and the two-order torque ripple is eliminated.Finally,this paper introduces a dual three-phase PMSM drive experimental platform and carries out experimental research to verify the related theory.