RESEARCH OF NONLINEAR DECOUPLED CONTROL LAW USING STATE VARIABLE FEEDBACK LINEARIZATION METHOD BASED ON THE CCM BUCK CONVERTER

Based on the differential geometry theory, an affine nonlinear mode of Buck converter working on current conduction mode (CCM) is set up by applying impulse mode integral method in this paper. Then the nonlinear coordinate change matrix and the nonlinear state variable feedback equations of the affine nonlinear system are proposed. At the same time the paper derives the state variable feedback exact linearization mode of Buck converter and get the decoupled control strategy between the current of conductor and voltage of capacitor. The research results show that the nonlinear decoupled control method is superior to the customer PI control method in the dynamic response performance and steady-stage error regulating characteristics. The results also show that the piecewise linear model as the Buck converter can be decoupled completely by using the state variable feedback exact linearization method, so it is a generality theory with practical significance.