The Application Research Of IMC For Induction Motor Speed Control System Based On DSP

In system of induction motor speed control, speed controller is usually conducted by traditional PI control. However, during the practical application,the traditional PI control is difficult to overcome the problem of system deterioration due to disturbance or motor parameters variations. In this paper,the internal model control(IMC) is combined with immune feedback algorithm,two-degree of freedom control and fractional-order control algorithm,respectively, then the whole is applied to induction motor drive system. And an experimental platform based on DSP is set up to verify the control performance of the three proposed algorithms.Firstly, by the properties of immune feedback algorithm adjusting the parameters of controller automatically, a immune internal model speed controller is designed by combining IMC with the immune feedback algorithm to improve the adaptive ability of induction motor speed control system. The experimental results show that the immune feedback algorithm has the function of adjusting controller's parameters in real time, which could overcome the influence caused by disturbance or motor parameters variation. Secondly, to optimize the anti-interference and tracking performance of induction motor speed control system simultaneously, two-degree of freedom control is introduced into the immune IMC, which has two parameters to adjust the anti-interference and tracking performance of induction motor speed control system, respectively. The simulation and experimental results show that two-degree of freedom immune IMC has all the advantages of two-degree of freedom control, immune feedback algorithm and IMC. It not only can make the speed controller aviod the influence of its parameters variation, but also can make the induction motor speed control system have good following,anti-interference performance and robustness. Finally, in order to overcome the tuning problem of fractional-order PI?D? controller who has five parameters, a fractional internal model controller is designed according to IMC structure,remaining two adjusting parameters ? and ?, and they can be set by phasemargin method. Simulation and experiment results show that fractional IMC not only can shorten the cycle of controller designing, but also can avoid choosing parameters blindly.