Research On Sensorless Control Strategy For High Power Brushless DC Motors

Brushless direct current motor(BLDCM)has been widely used in various fields of our daily life due to its advantages which contain high efficiency,low noise,small size,good reliability and easy maintenance.Therefore,the progress and development of its control technology are closely connected with our lives,and the sensorless control technology has become a hot field of research.In this subject,an in-depth study of the sensorless control strategy of the brushless DC motor has been finished for the application scenario of high bus voltage and high powerFirstly,based on the six-step control method,a new sensorless detection strategy was designed for the shortcomings of the traditional sensorless control strategy in high bus voltage and high power application scenarios.And design the underlying timing Logic and terminal voltage detection logic combined with theoretical analysisSecondly,this paper creatively proposes a startup method based on software that needs to rise the frequency and voltage to improve the deficiencies of the traditional three-stage startup method and the startup method based on hardware.The method simplifies the complexity of hardware circuit design and increases the probability of startup.Thirdly,based on the theoretical analysis of this subject,MATLAB/Simulink is used to establish the controlling strategy model.The controlling logic and sub-modules are interpreted in detail.Then simulation experiments are conducted to verify the feasibility of the control methodFinally,combined with the applications of this subject,a hardware experiment platform was established,and the hardware was optimized for the working situation which has high bus voltage and high power.A discharge circuit was designed in the terminal voltage detection,and finally,combined with the underlying software platform,the testing and debugging was done to verify the performance of the control strategy.