Research Of PMSM Vector Control On Model-based Design In Mediun And Low Speed Conditions

Nowadays the international community pay more and more attention toenvironmental and energy problems. For being clean, environmental protection and highefficiency, EV(electric vehicle) gets favored by people, and also causes the attention ofvarious kinds of big automobile manufacturers. Since PMSM(permanent magnetsynchronous motor) has high power density and high efficiency, it certainly becomes thefirst choice of EV drive motor. The control strategy of PMSM mainly includes the vectorcontrol and direct torque control. The vector control is dependent on precise mathematicalmodel of the motor, this leads to weak robustness, and that’s right the problem thispassage tried to research and solve. So the technique of ADRC(Active DisturbanceRejection Control) with the function of disturbance observer and compensation wasbrought in the speed loop of the vector control system. Beside, the disadvantages of thetraditional motor control strategy development include low efficiency, long cycle, highcost and poor reliability. That’s why it is obviously difficult to adapt to the EVdevelopment requirements of development cycle, cost and reliability of the code. So thispassage applied a method of design and development called MBD(model-based design) tothe development process of drive motor control strategy. In conclusion, this passagefocused on the two aspects mentioned above, the research contents were as follows:Firstly, the basic structure and working principle of PMSM was introduced, themathematical model of PMSM under different coordinate system was deduced, and theconversion process between two different coordinate system were expounded. On thebasis of that, this passage made a deep theoretical research and analysis for the realizationof the vector control strategy, and built the overall design architecture about the PMSMvector control.Secondly, the working principle of ADRC technique was introduced. Combiningwith the state equation of PMSM speed, the vector control scheme based on ADRC speedloop was designed. According to the scheme, a simulation model of vector control basedon ADRC was set up in simulink, and tests were made on PMSM about its performanceof starting, acceleration and load, under the condition of middle or low speed. Thesimulation results show that the vector control based on ADRC has stronger robustnesscompared with the conventional PI. Thirdly, combined with MMC motor control strategy development platform andbased on the development process of MBD, the requirements document were establishedaccording to the project needs in the first. On the basis of the simulation model, the codemodel was set up based on ADRC model of vector control. Then the association wasestablished between model and requirements. Next, changing from model to code wascompleted automatically, and the bi-directional tracing between code and model wasrealized at the same time. After that the code got improved.Finally, according to the requirements of EV power testing, the performance testingon PMSM under the condition of middle or low speed was made In the laboratoryexperiment platform. The experimental results show that, the vector control based onADRC has good dynamic characteristic and robustness, which actually meets theperformance requirements for EV. And of course the expected target has been achieved.