Comparative Study on Vector Control and Differential Geometry Decoupling Control Method of Induction Motor

Induction motor is a strong coupling, multivariable and nonlinear controlled object. This paper makes a comparative study of two decoupling control methods based on the theory of differential geometry and the classical vector control. The former uses nonlinear multi-input-multi-output state feedback decoupling method based on the theory of differential geometry, the latter uses rotor field-oriented control method. Results show vector control only realizes static decoupling between speed and rotor flux, which can not realize dynamic decoupling, In the process of transient regulation of flux linkage, the rotor speed subsystem doesn´t achieve decoupling and rotor speed varies with response to flux linkage. Only when flux linkage becomes stable, rotor speed subsystem achieves decoupling. But the decoupling method based on the theory of differential geometry can realize full decoupling between flux linkage subsystem and rotor speed subsystem in the dynamic process, which have no influence on each other in the process of dynamic flux linkage or rotor speed regulation. Simulation and experimental results are demonstrated to prove decoupling method based on theory of differential geometry is better than that of vector control