Hybrid modelling and simulation of time-delay elements

Most general purpose simulation languages do not provide support for modelling and simulation of delay elements with variable delay times. In this paper, combined discrete-event / continuous-time (hybrid) models of time delay elements are treated. An introduction is given to discrete event and continuous-time models of delay elements. The hybrid models are compared to the traditional models using a step and sine input function. The hybrid models outperform the traditional models on accuracy, computation time, and stability. The most important aspect of the hybrid models with a variable delay time is that between two adjacent sample points, the volume entering the element is constant.