An experimental comparison of several nonlinear controllers for power converters

This article summarizes the results of an experimental comparison of nonlinear control algorithms on a DC-DC power converter of the boost type. It compares five algorithms, including the linear design, with respect to their ease of design and their closed-loop performance. For all these algorithms local asymptotic stability of the desired equilibrium is ensured. The motivation of the present study is not to illustrate the validity of these theoretical results, but to test their performance when confronted with a real physical application where situations not predicted by the theory will arise. The behavior of the schemes is compared with the following basic criteria: transient and steady state response to steps and sinusoidal references, attenuation of disturbances in the power supply, and sensitivity to unknown loads. Particular emphasis is placed throughout on the flexibility provided by the tuning parameters to shape the responses. Even though this issue is not always appreciated in theoretical studies, we have found it of prime importance in experimentation.