Research Of Deadbeat Current Controlled Permanent Magnet Synchronous Motor

In the field of industrial production,especially robots,numerical control machine tools,permanent magnet synchronous servo system has an important position.With the development of intelligent manufacturing equipment,the performance of perm anent magnet synchronous servo system is also increasing.The permanent magnet synchronous servo system generally adopts a three-loop cascade control structure of position loop,speed loop,and current loop.In this structure,the response speed of the cur rent loop directly determines the response speed of the servo system,and the bandwidth of the current loop is increased to improve the servo.The key to dynamic system performance.Deadbeat current contro is equivalent to high-gain P control,which increases the bandwidth of the current loop in principle.However,it is based on a precise mathematical model of the motor.In the actual application process,the system’s robustness and traceability are poor.Therefore,this subject proposes an improved Deadbeat current contro.Firstly,based on the idea of coordinate transformation,the mathematical model of PMSM is transformed from three-phase stationary coordinate system to two-phase rotating coordinate system.The vector control architecture of permanent ma gnet synchronous motor is introduced and the principle of space voltage vector modulation is analyzed.Then,according to the mathematical model of PMSM,the mathematical model of traditional deadbeat current control is deduced in detail,the generation process of sampling delay and the influence on the stability of the current loop are analyzed and the sampling delay compensation is analyzed.The motor parameters,Inductance,flux linkage)on the static dynamic performance of the system.In order to overc ome the drawbacks of the traditional deadbeat current control,an improved deadbeat current control is proposed in this paper.That is to say,the differential flat theory is added to the deadbeat current control algorithm,The stability of the system and its influence on the current steady-state error were analyzed.The discrete integral was added into the deadbeat current control without beat to eliminate the current steady state error caused by the change of the motor parameters.The range of the value o f the integral coefficient was analyzed and carried out Anti-Windup,a fast tuning method is proposed for speed loop controller parameters.The correctness and practicability of the proposed theory are verified by simulation.Finally,an improved deadbeat current control experiment is carried out based on the core control platform TMS320F28335,which is the motor control chip of Texas Instruments of USA.The validity and practicability of the theory proposed in this paper are verified through experiments.Experimental results show that the improved deadbeat current control is equivalent to two-degree-of-freedom PI control,which makes the current loop have good response speed,robustness and tracking accuracy.