The permanent magnet synchronous motors (PMSM) are used as servo motor for precise
motion control and are used as generator to generate electrical energy driven by wind energy.
There is large variation in inertia due to varying load and parametric uncertainty in PMSM.
The design objective of this paper is to analytically determine the relative robust stability of
PMSM with parametric uncertainty using Kharitonov theorem and Routh stability criterion.
The conventional integral controller (IC) and two robust internal model controllers (IMCs) are
used for relative robust stability analysis of speed control of PMSM. The frequency domain
performance specifications like gain margin (GM) and phase margin (PM) are taken for
relative robust stability analysis, and the effect of controllers on time domain performance
specifications such as settling time (ST), rise time (RT) and overshoot (OS) is also studied.