Research On Robust Control Method Of AC Motor Speed Control

The AC motor speed control system in various industrial drive applications has been widely used.However,AC motor is a multi-variable coupled nonlinear system,and motor parameter variations and load disturbances and uncertainty influence.Therefore,how to improve the robust performance of AC motor speed governing system become the focus and goal of current research in the AC drive field,the main solution is the realization of the new control strategy and the sensorless method.This paper focuses on the nobust observer and robust controller in the vector control system based on the above analysis.The specific research work includes the following aspects:An internal model control strategy based on the advanced internal model control technology is proposed for the interaction between the d axis and the q axis in the vector transformation.The mathematical model of induction motor is established,and the basic control mechanism of two degree of freedom internal model control is analyzed.The stability of the system is discussed,and the structure design and parameter calculation of current regulator are also discussed.It can be concluded that this method has low requirement of model accuracy,good decoupling effect and strong robustness.At the same time,the two degree of freedom internal model control structure can simultaneously adjust the following performance and anti-disturbance performance of the system,so that the performance of the system can be optimized.The internal model control(IMC)has been widely attended for its simple structure and easy realization.Its control performance has a relationship with the filter time constant directly,so that high-performance is influenced in the application of motor drive system.A novel method of two-degree-of-freedom internal model control strategy of induction motors using the immune algorilhm(IA)is proposed in this paper.The immune algorithm is studied on the basis of the immune response system and the algorithm realization is analyzed The immune algorithm is introduced in the two-degree-of-freedom internal model controller,and the filter time constant adjustment on-line is realized by taking full advantage of the adaptivity of the immune algorithm.The simulation and experimental results verify the effectiveness of two-degree-of-freedom internal model control strategy of the induction motor using the immune algorithm.The permanent magnet synchronous motor robust H∞ observer method to estimate the speed is proposed.A nonlinear mathematic model of permanent magnet synchronous motor,the q-axis current iq as input signals to design the state feedback controller,observer is obtained by solving the Riccati equation of the feedback control law,to ensure the robust H-infinity observer of the actual state of the target tracking.When will the algorithm in permanent magnet synchronous motor without speed sensor vector control system experimental platform is verified,the income estimates speed in full speed range has a good tracking performance;system state mutation or load disturbance,disturbance suppression effect is good;and has strong robustness to motor parameters change.The H-infinity speed observer replace mechanical sensor,of permanent magnet synchronous motor speed estimation,but its observation performance and the weight coefficient selection has a direct relationship is realized,which limits its application in high performance AC drive system.The particle swarm algorithm is introduced in the H-infinity robust observer,makes full use of the particle swarm optimization algorithm of the memory of the observer for parameter tuning and optimization,to further improve the PMSM without speed sensor vector control performance of the control system,has better dynamic performance and anti-jamming performance.