Transient Stability Enhancement of DC–DC Boost Converters Feeding Constant Power Loads in DC Microgrid Applications via Composite Nonlinear Control Techniques

In this paper, a composite nonlinear controller is developed for stabilizing a constant power load (CPL) feeding DC-DC boost converter (DBC) for DC microgrid applications. If the boost converter is not properly controlled, the negative incremental impedance (NII) of CPLs can cause DC-bus voltage instability. As the original model is not adequate for designing the proposed controller, the nonlinear dynamical model of the DBC is transformed into Brunovsky’s canonical forms. Large load and input voltage changes hinder the controller’s performance. Therefore, the dynamical model has been updated to include constrained external uncertainty. Then, the proposed hybrid controller, which is a combination of the nonlinear backstepping controller and the sliding mode controller, is designed. The sliding mode controller has a double-integral-based…