Research On Redundant PMSM And Fault-tolerant Control

Under the premise of meeting the requirements of "high power and large torque",the main purpose of this paper is to design a motor servo system for the paddle system of wind turbines.The working environment of the motor servo system is abominable and its vibration is violent.Sometimes it is also threatened by high salinity and high humidity.The motor servo system is prone to failure.Once the wind turbine generator fails,it will cause huge economic losses.As a result,the motor servo system is required to have high reliability.In general,the reliability of motor servo system can be improved form two respects.On the one hand,it's to improve the reliability of the motor itself.On the other hand,it's to take fault tolerant control technologies.A multi redundancy permanent magnet synchronous motor and its fault-tolerant control system is developed according to the characteristics of various fault tolerant motors and fault-tolerant control technologies.First,the basic principle of the PMSM servo system is described.The mathematical model of the multi redundancy motor and fault tolerant control system is established.The basic performance and fault tolerant performance of the multi redundancy servo system are analyzed based on Matlab/Simulink.Second,in order to make the multi redundancy motor servo system cut off the fault margin in time,it is necessary to have the ability of fault diagnosis.Meanwhile the stator windings turn-to-turn short circuit fault is very common.And it is difficult to diagnose and is easy to cause serious consequences.As a result,the short circuit fault is studied in this paper based on JMAG-Designer.The electrical parameters after short circuit fault are compared and analyzed.In addition,due to the change of the system characteristic parameters after the motor fault redundancy is cut off,the original parameters of PID controller are not suitable for the new system.Based on Matlab/Simulink,particle swarm optimization algorithm is used to optimize the parameters of PID controller,and the simulation results meet the expected requirements.Third,the reliability analysis of the multi redundancy motor servo system is carried out.The fault tree model and reliability model of the traditional motor servo system and the multi redundancy motor servo system are built.The reliability mathematical models of each weak link are established,and the reliability and MTBF of traditional motor servo system and multi redundancy motor servo system are calculated.At last,according to the required technical parameters,the structure of the multi redundancy permanent magnet synchronous motor is designed.At the same time,the control strategy of the whole motor servo system is planned,and the corresponding hardware circuit is designed.And the PCB board diagram of the hardware circuit is drawn.In order to verify the theory put forward in the paper,the experimental platform of multi redundancy motor servo system was built.Then multi redundancy motor series experimentsand and control system series experiments were carried out.The experimental results show that the basic performance of the motor meets the requirements.The electrical parameters of each redundancy have good consistency.The current loop and speed loop of the control system can drive multiple redundancy simultaneously.And the response characteristics of them meet the requirements.The whole motor servo system has good fault-tolerant performance and achieves the design goal.