Nyquist stability test for a parabolic partial differential equation

摘要

The paper describes a Nyquist stability test applied to a parabolic partial differential equation. The PDE describes the temperature distribution of composite structures with linear inner heat source. The distributed transfer functions have been developed by the transmission matrix method. To analyze the stability of the system we define a virtual feedback-loop and apply the Nyquist stability test. The method described is easy to use and avoids numerical problems arising from locating the infinite number of system poles by numerical approximation.