Analysis of Practical Non-minimum Phase Systems by Transfer Function Approach

Abstract

In this paper, practical non-minimum phase systems are analyzed using respective system transfer functions only. The analysis is done to identify the presence of anomalous time-domain characteristics such zero-crossings, overshoot (due to zeros) and initial undershoot in step response of practical non-minimum phase systems using the system's transfer function model only. For these anomalies, theorems of detection are discussed, illustrated with numerical examples and validated using four different practical systems such as DC-DC boost converter, the hydro turbine of a hydro-electric plant, cart-inverted pendulum and coupled-tank systems. Each of these systems is briefly described and the validation (using the theorems) is proved by verifying with corresponding systems' step responses. Along with this, a short analysis is proposed regarding the magnitude of initial undershoot and its relation with relative pole-zero positions of a system. © 2018 IEEE.