Research On Multi-motor Synchronous Coordination Fault Tolerance Method Under Inverter Fault

With the rapid development of servo technology,multi motor drive system is widely used in various industrial production processes.For the equipment with multi motor drive system,the coordination between motors and the reliability of motor system play a decisive role in product quality and production efficiency.In order to improve the synchronous coordination performance of multi motor drive system in case of fault,this paper takes the multi motor synchronous coordination control system composed of multiple BLDC motors as the research object,and studies the practical fault-tolerant control method for inverter fault.This paper mainly includes the following contents.Firstly,a multi motor synchronous coordinated fault-tolerant control method based on fault-tolerant coordination coefficient is proposed under the adjacent cross coupling control structure.The mechanism of inverter fault is analyzed,and the control model of Brushless DC motor system under fault is established.Aiming at inverter fault,a fault detector based on improved multiple sequential likelihood ratio test is designed.The traditional multi motor synchronous coordinated control system is transformed by adding fault detector and faulttolerant decision-making module.By adjusting the fault-tolerant coordination coefficient,the parameters of each motor subsystem are dynamically changed In order to achieve the purpose of fault-tolerant control,the synchronous accuracy between motors under fault is maintained.Secondly,the reason for the increase of synchronization error between motors under inverter fault is analyzed and a multi motor synchronization fault-tolerant control method based on cooperative control theory is proposed.The exponential convergence disturbance observer is designed to estimate and compensate the disturbance caused by load change,parameter perturbation and unmodeled dynamics,so as to improve the anti-interference performance of the system and solve the problem that the cooperative controller is sensitive to the model parameters;the fault-tolerant decision-making module and fault-tolerant actuator are designed to dynamically change the cooperative control manifold according to the operation state of the multi motor system to maintain the synchronization of motors under inverter fault In order to reduce the synchronization error in the transient process of fault response and further optimize the effect of fault-tolerant control,a collaborative control method with adaptive parameters is designed to dynamically adjust the relationship between synchronization performance and tracking performance of multi motor system.Finally,an experimental system based on TMS320F28335 is built to verify the effectiveness of the proposed fault-tolerant control method.The overall structure of the experimental system is determined by analyzing the requirements of the multi motor synchronous coordinated fault-tolerant control system and giving the technical indicators;the selection and design of the key components of the system are completed,and the hardware platform is built;the overall software architecture is designed according to the functional requirements,and based on the design results Real time operating system develops driver layer and application layer software to realize data communication between motor systems and coordinate task advance sequence;based on the built experimental system,the correctness of the proposed fault tolerant control method is verified through synchronous control experiment under non fault condition and synchronous control experiment under inverter fault condition.