On Preserving Passivity in Sampled-data Linear Systems

Passivity, a well known phenomenon in several engineering areas, is generally lost under direct discretization. This paper characterizes a class of linear systems preserving passivity under sampling and introduces a new methodology preserving continuoustime passivity under discretization. This methodology is based on choosing a proper output which preserves the passivity property while keeping the continuous-time energy function. An analytical formulation and numerical examples are provided.