Dynamic physical limits of boost converters: A benchmarking tool for transient performance

The control of boost converters presents a special challenge due to the its non-minimum phase behaviour, forcing a slow transient response when traditional linear controllers are employed. In order to achieve enhanced dynamic response, more complex controllers have been proposed (e.g.: adaptive, non-linear, boundary, etc.), but the improvements introduced by each one of them cannot be objectively assessed in the absence of an optimal standard reference. This work introduces the theoretical physical limits of performance of boost converters, providing valuable insight into the behaviour of the topology and setting a strong benchmark point for the dynamic performance evaluation. The theoretical optimal transient response is found in a normalized geometrical domain and characterized by closed-form expressions, providing simple, intuitive, and general results valid for any combination of LC parameters and voltage levels. The characterization of the ideal transient is validated by experimental results demonstrated with a 50W boost converter operating near the physical limit of performance.