Research On Permanent Magnet Synchronous Motor Control Method For Electric Wheel Vehicle

In the world, energy shortage is growing and environmental pollution is worsening.With the advantages of zero tailpipe emission, wide energy source, High energy utilization,electric vehicles has been concern widely. Especially, in-wheel motor drive electricvehicle has simple structure, high car space utilization, simple operation and stands out inelectric vehicles. It has become a research focus in the world’s automotive industry.The paper chooses the permanent magnet synchronous motor as hub motor, which isapplied to electronic differential system of In-wheel motor drive electric vehicle. Thedirect torque control method was adopted to control the permanent magnet synchronousmotor. The control doesn’t need vector conversion，dependences on motor parameterssmall and responds fast. But it has the torque and flux ripples. The paper has done researchon the issues.First, the development of electric vehicles at home and abroad was analyzed in thepaper. The analysis showed that in-wheel motor drive electric vehicle has importantsignificance for the development of electric vehicles. While the permanent magnetsynchronous motor and the control method was introduced briefly.Then, the mathematical models of the permanent magnet synchronous motor invarious coordinate systems and the principle of direct torque control were showed in thepaper. And the system model of the permanent magnet synchronous motor direct torquecontrol was made. To solve the problems of the system, the introduction of zero vectorsand particle swarm optimization to improve the direct torque control method waspresented. The introduction of the zero voltage vector made the vector chooses more andreduced the torque ripple effectively which is caused by direct torque control. More, the PIcontroller was optimized by the particle swarm optimization. After optimization, thecontroller has the performances of convenient parameter tuning, good robustness, lesstorque ripples, which improves the stability of the system.In the MATLAB environment, the system simulation model was built. The simulationresults showed that the presented direct torque control method based on zero vectors andparticle swarm algorithm reduced the torque and flux ripples and solved disturbance problems existed in the control system significantly. The overall performance of thesystem was improved.Finally, to do extension studies of the improved direct torque control method, aelectronic differential system was designed, which combined the motor control methodand the electronic differential strategy. According to the speed calculated by the electronicdifferential strategy, the electronic differential system controls the motor to execute thesteering. The simulation results showed that the electronic differential system based on thepermanent magnet synchronous motor control method which is presented in this paper isfeasible and effective.