Abstract:

As the existing nonlinear control methods are difficult to apply to practical nonlinear dynamic systems,a discrete synergetic control strategy is proposed in this paper.In the investigation,first,the characteristics of the discrete synergetic control and its application to DC-DC converters are analyzed.Next,the general forms of the syner-getic controller are summarized,and the existence and hitting conditions as well as the convergence speed of the control manifold are discussed based on the similarity of the variable structure control to the synergetic control.Then,the stability and robustness of the closed-loop system driven by the synergetic controller are investigated.Finally,the effects of control parameters on the control performance are discussed.Both the analysis and Simulink simulation results show that,with the discrete synergetic control,manifolds can be exponentially reached from any original states,the control system asymptotically stabilizes at the objective working point,and the invariance against system parameter variation and external perturbation can be achieved when the matching conditions are satisfied.

Key words: discrete control, synergetic control, DC-DC converter, variable structure control, robustness