Study on Nonlinear Control Strategy for the Permanent Magnet Synchronous Motor

　　Study on Nonlinear Control Strategy for the Permanent Magnet Synchronous Motor
　　Permanent Magnet Synchronous Motors(PMSM) have been widely used in industrial and agricultural production and the field of Aeronautics and Astronautics for their advantages, such as compactness,high efficiency,reliability and adaptability to the environment.Along with the continuous development of these areas,the speed control system for PMSM urgently needs to have http://www.999magnet.com/products/142-neodymium-price better precision,wider speed-regulating range and faster response.Based on the overview of PMSM speed control system development,this thesis firstly presents the process of building the mathematic model for an Interior Permanent Magnet Synchronous Motors (IPMSM),and then we mainly develop a few nonlinear control algorithms of PMSM for the speed regulation and tracking based on this model.PMSM is a highly nonlinear and coupling,structure varying,and multivariable object. Firstly,the mathematical model of PMSM is built under the d-q coordinates.After analysis of vector control strategies,we chose i_d=0 control strategy to decouple the system.For the highly nonlinear characteristics of PMSM,backstepping control method is adopted.This method has fewer design parameters and can be easily realized,furthermore the design rule of backstepping makes global asymptotical stabilization with Lyapunov function.Taking into account the variability of the parameters in PMSM,adaptive parameter estimation method is introduced into the backstepping control under Lyapunov stability.With the promotion of applications and different requirements in different areas,the speed is asked to be changed over time.This thesis designs a new backstepping controller to make the speed control system effectively and closely track the varying speed.Because the presence of speed sensor is undesirable for cost,maintenance and reliability reasons,a kind of sensorless backstepping control based on a speed estimator is designed in this thesis.All the above controllers are proved to be effective by the theory and simulation.The thesis is summarized at the end and some conclusions and future works are pointed out. 更多还原