Synchronous Control Of Multiple Pmsm Based On Sliding Mode Control

With the development of basic science and applied technology,PMSM has been widely concerned and applied in production and life with its advantages of good speed regulation performance,efficient power output and simple and easy maintenance structure.And the synchronous control system composed of multiple PMSMs has broad application prospects.Due to its nonlinear and strong coupling characteristics,synchronous control has become a hot and difficult point in this field.Therefore,the synchronous control of multi-PMSMs is studied based on multi-PMSM system.Firstly,the control problem of single PMSM is considered.By analyzing the internal structure and driving principle of the motor,the mathematical model of PMSM is established.Then,the motor model in different coordinate systems is derived to analyze the control principle of PMSM in vector control with space vector transformation.At the same time,the vector control method of_di=0 which is suitable for this paper is selected by combining with the SVPWM.For the coupling problem of multi-motor synchronous control,various coupling control structures are analyzed and verified,and the shortcomings of various existing synchronous coupling control strategies are summarized.Then,the mean-coupling synchronous control strategy is proposed.The theoretical analysis and simulation verification prove that this synchronous control strategy has the characteristics of global compensation,simple operation form,high dynamic response and high synchronization efficiency,which can solve the coupling problem in synchronous control.And the synchronization convergence problem of tracking error and synchronization error is solved by designing coupling errors with the mean-coupled synchronous control strategy.Finally,for the error convergence problem in multi-motor synchronization process,a non-singular finite-time sliding mode controller is designed to realize the finite time synchronization convergence of tracking error and synchronization error.However,the upper bound of the error convergence time is related to the initial state of the system which has certain limitations.Therefore,the non-singular fixed-time sliding mode controller is designed such that the upper bound of the error convergence time is only related to the known set parameters.At the same time,considering the external disturbances existing and the influence of the unmodeled uncertain parts in the system,the adaptive upper bound adaptive estimation law is designed to compensate the disturbance and improve the stability of the system.It is verified that the adaptive non-singular fixed-time sliding mode controller has faster convergence speed and stronger robustness with simulation analysis.