Synchronous Control of Multi-Motor Systems Using an Improved Relative Coupling Control Structure

In this paper, an improved relative coupled control structure (IRCCS) is proposed to suppress the overshoot and decrease the synchronization error of multi-motor synchronous control systems (MMSCSs). Different from the relative coupled control structure (RCCS), the IRCCS simplifies the speed compensator and combines with the idea of differential tracking controller, as well as introduces an improved differential negative feedback signal to speed loop controller which makes the speed controller desaturate in advance thus effectively suppressing the overshoot of the system. In addition, since the electromagnetic time constant is much smaller than the mechanical time constant, the synchronous error of MMSCSs can be decreased by introducing a compensation with the same synchronous compensation information as the speed loop controller to current loop controller. Finally, simulation analysis of the IRCCS is carried out on three-motor control system, and simulation results show that the IRCCS has better synchronization performance than the RCCS.