Comparative study of the synchronous control for rigidly coupled electro-motors

Abstract

Abstract Multiple electro-motors rigidly coupled by multi-points gear meshing is of a typical driving structure, and the synchronous control between parallel motors is the key issue about system stability and performance. Firstly, the drooping control is introduced to modify traditional speed parallel control (SPC) method; classical torque master-slave control (TMSC) using soft control parameter is also proposed as contrast. Subsequently, the basic principle of vector control with rotor flux orientation is described; the non-linear time-varying gear dynamics at the unbalanced pinion-gear meshing stage are also studied. Based on the mathematic analysis, simulation models under three different control methods are established in Simulink, and are comparatively studied against backlash, contact ratio and motor parameter deviations between multiple chains. Finally, SPC with drooping control (SPCD) and soft TMSC (STMSC) are applied on a test rig. The simulation and experimental results show that, SPC, SPCD and STMSC separately has advantages in speed tracking, system stability and torque synchronization, and should be used according to specific preference.