Research On Sensorless Direct Power Control Of Synchronous Reluctance Motor

The Synchronous reluctance motor(SRM)has high efficiency,accuracy and power factor,and its manufacturing cost is low.Therefore,it has a wide application prospect in the field of low-cost variable frequency drive such as the pumps and fans.However,the application environment of pumps and fans is complex and changeable,and the load varies greatly.The introduction of traditional physical sensors will increase the manufacturing cost and the instability of the control system.Therefore,the sensorless control method should be adopted in this application.However,the existing sensorless control methods have some problems,such as small starting moment and weak load capacity.How to effectively realize the Position-free control of synchronous reluctance motor and improve its power and energy index has become a research hotspot,which is also the key content of this topic.Firstly,the mathematical model of synchronous reluctance motor is deduced,and the traditional constant voltage-frequency ratio control method is introduced.In order to improve the stability of the traditional V/F control and its starting torque and load performance,a power compensation based V/F control system of synchronous reluctance motor is proposed.Furthermore,in order to verify the effectiveness of the algorithm,the principle block diagrams of the traditional constant voltage-frequency ratio control system and the constant voltage-frequency ratio control system based on power compensation for synchronous reluctance motor which based on the idea of traditional constant voltage-frequency ratio control and power compensation are designed in this paper,and The simulation models are built in Matlab/Simulik,and the performance of start-up,steady-state and anti-load disturbance are simulated and compared.The simulation results show that the constant voltage-frequency ratio of synchronous reluctance motor based on power compensation has better start-up,steady-state and load disturbance resistance than the control system.Finally,in order to prove the design principle and the accuracy of simulation results,the corresponding experimental test platform is built,which mainly consists of synchronous reluctance motor,driver,transformer,oscilloscope,upper computer,speed and torque measuring instrument and magnetic powder brake.The constant voltage-frequency ratio control algorithm of synchronous reluctance motor based on power compensation is written in C language on CCS software.It mainly includes V/F control,amplitude and angle compensation of stator space voltage vector,SVPWM modulation,PI regulation,current sampling and current-voltage protection.The experimental results of motor start-up,steady-state and anti-load interference onthe experimental platform prove the feasibility and superiority of the constant voltage-frequency ratio control method of synchronous reluctance motor based on power compensation.