Design Of Closed-loop Controller For Brushless DC Motor Speed

This paper mainly focuses on the research on the speed closed-loop controller of the brushless DC motor.Based on the relevant parameters and control performance indicators of the existing brushless DC motor,a reliable double closed-loop control system of speed and current is designed.Use Matlab / Simulink software environment to build a simulation model of BLDCM speed control system.Using the simulation model,it is convenient to modify and debug the functional modules,further complete the design of the speed control system,and complete the corresponding hardware circuit design and control program writing.First,the paper briefly introduces the great advantages of brushless DC motors compared to traditional brushed DC motors,introduces the wide range of applications of brushless DC motors,and summarizes the technological achievements and valuable research hotspots that have been made in the current BLDCM speed control system research.For BLDCM,deducing its mathematical model,analyzing its working principle,integrating its functional modules,and using tool software,it can successfully build a simulation model for its control system,so as to realize the basic functions of position sensor simulation and induced electromotive force solution.According to the simulation model,the BLDCM is simulated and tested,and the open-loop characteristics,closedloop characteristics,load mutation and other simulation analysis are completed,and the adjustment parameters of the closed-loop speed controller are determined.According to the simulation results,a soft-start method to gradually increase the duty cycle is designed to effectively suppress the motor starting current impact and starting torque ripple.Then,based on the control model and simulation results,the hardware circuit design with DSP as the core is completed,the models and parameters of the main components in the control system are determined,and the signal acquisition circuit,signal isolation circuit and DSP minimum system are given.Design scheme of key circuits.According to the hardware design plan,the corresponding software design ideas are proposed,the composition and functions of the application software are introduced,and the program flow diagram and the specific design of key programs are given.Finally,the designed BLDCM controller is tested to verify the effect of speed control and the running performance of the prototype.The test results show that the control is effective and practical,and the performance is reliable.In the design process,we must strive for the development of new functions,as well as give full play to the existing effects of resources,and we must closely integrate the design with the needs of specific projects to perfectly solve practical problems.