基于模型解耦的Buck变换器滑模控制

For the voltage-controlled Bück Converters, its Performances are restricted by the circuit nonlinearity. In order to solve the problem, a sliding mode (SM) control approach was proposed based on model decomposition to improve the quality of power Output. Based on the Kirchhoff' s circuit theory, a unified mathematic model of bück Converters in the both cases of switch on and off was established, following the traditional design of the voltage Controller on the basis of the SM equivalent control theory. The voltage variable was chosen to construct a two-layer sliding surface, which differs from the traditional model decomposition. The current is also under the control. Then based on the Output redefinition approach, the System was decomposed into an input-output Subsystem and a zero dynamic Subsystem. Therefore, the quality control of the power Output was changed into the stability problem of the input-output Subsystem. By combining the four cases, the relationship of the Controller parameters and the System stability was deduced. Simulations validate this paper with advantages of fast response, good steady Performance and wide application.