Electrical Drive in/around Torsional Resonance Analytical Model

In this paper a complete analytical model of an electric drive in/around torsional resonance is presented. The model includes the electrical equations of a permanent magnet synchronous machine (PMSM), the mechanical characteristics represented by a two-degree-of-freedom (2DOF) system and the equations describing the control system. The objective is to obtain formulae on hand to predict both the electromagnetic and the shaft torque harmonics around resonance. Accounting for the various aspects, this model reveals the interconnections between electromagnetic, mechanical and control phenomena. The overall system solution is obtained by applying the small variations method and transfer functions formalism. The results are confirmed by simulations in Matlab/Simulink environment.