A Laboratory Exercise for System Identification of Passive LTI System and its Dynamic Simulation

This paper outlines the crucial steps while performing system identification on a linear time invariant (LTI) passive equipment to obtain a model apt for dynamic simulation. The device under test (DUT) is a single-port voltage transducer. A concise overview of system identification methods is presented in this paper and later graduate towards frequency response estimation (black-box) approach. Using vector-fitting technique the experimentally obtained frequency response is transformed into a state-space representation which are readily used for dynamic simulations. The key assumptions considered in the paper while developing dynamic model are that the DUT is LTI and passive. Coherence as an indicator is used to assess the LTI nature from the input-output measurements. Similarly, passivity conditions are checked to assess model's passivity. The applicability of the developed dynamic model are highlighted. An experimental set of time-domain excitations is used to verify the simulated dynamic model. This exercise can be an effective laboratory course component, introducing students to essential concepts in system identification and dynamic simulation.