Synthesis of dissipative nonlinear controllers for series resonant DC/DC converters

This paper describes analytical advances and practical experiences in a nonlinear controller design methodology for series resonant DC/DC converters. The control goal is to maintain the output voltage (which is the only measured variable) in the presence of large-load perturbations by varying the switching frequency. The proposed methodology utilizes large-scale, nonlinear switched, and generalized averaged models, and the resulting closed-loop system is exponentially convergent under typical operating conditions. The designer has a direct handle over the convergence rate, and the nonlinear controller requires only the usual output voltage measurements, while the load variations are estimated. The control structure allows for variations in both resistive and current loads. The dissipativity-based nonlinear controller is implemented in affordable analog circuitry and evaluated experimentally.