Algorithms of Robustly Stable Systems for Synchronous Electric Drive in Field Weakening Mode

Decomposing control algorithms for a robustly stable nonlinear interconnected vector control system for the speed of a synchronous motor are presented. The equation of algorithms is obtained in a closed form according to the classical models of Lagrange and Euler, which reflect the fundamental laws of dynamics. The presented results of mathematical modelling (transient processes of electromechanical coordinates of the system) illustrate that the nonlinear system has the properties of robust stability. The field weakening mode is used to limit the voltage of the inverter in the second zone, due to the known (reference) trajectory of the angular speed of the motor rotor and its first (limited) time derivative. The paper investigates how a reference trajectory of angular speed affects the dynamics of an adjustable synchronous electric drive in vector control.