Optimal energy-based stabilizing controllers for DC-DC converters

摘要

This paper aims at presenting new ideas and in-sights towards a novel optimal energy-based stabilizing control approach for power electronic converters. The stabilizing or Lyapunov-based control paradigm is well-known in the area of energy-based control of DC-DC converters. Such laws rely on an energy-based Lyapunov function to control the speed of the energy dissipation by which power electronic converters reach their steady-state operation and are parameterized by a positive scalar λ, whose selection is critical for the performance of the closed-loop system. A typical optimal control problem for stabilizing control laws is formulated, whose solution involves the search for the optimal value for λ. Two different averaging continuous-time models for DC-DC converters are adopted (nonlinear and linearized) and corresponding methods for solving the optimal control problem are presented. In the general nonlinear case, the optimal control problem is reduced to a nonlinear optimization problem for which analytical gradient information is available. In the linearized case, the optimal control problem is reduced to a simple optimization problem of finding the minima of a polynomial function of λ. The methods are evaluated in a boost converter using simulation.