Research And Implementation Of BLDCM Control Technology Based On Hall Sensor

Brushless Direct Current Motor(BLDCM)with its simple structure,high efficiency,with good speed performance characteristics,widely used in industrial control,high-end home appliances,consumer electronics and many other areas.The traditional square wave control method of BLDCM is simple,but there is a large torque ripple,it is difficult to meet the increasing application requirements.In recent years,the PWM ON PWM modulation control can improve the control performance of the BLDCM.For non-standard back EMF waveform of the BLDCM,the vector control is usually able to achieve better control performance.For more complex control strategies,more accurate rotor position information is required.Increasing the mechanical sensor will increase the cost and space,and its detection accuracy is also susceptible to environmental influences.Most sensorless algorithms are complex,difficult to start,and have poor practical applicability,and it can not replace the sensor solution yet.Hall sensors are widely used in BLDCM control systems.In the case of cost-limited,volume-constrained non-high-precision control,the use of low-resolution Hall position sensor is a better choice.In view of the above problems,this paper proposes a method to realize vector control and PWM ON PWM modulation control based on improving the low resolution Hall signal for speed and position detection resolution.The mathematical model of BLDCM is deduced,and the basic principle of vector control and PWM_ON_PWM modulation control is studied.The motor speed and rotor position estimation method based on three phase Hall position signal are studied in detail.By analyzing the errors and problems existing in the three phase Hall estimation method,the strategies to improve the accuracy of the speed and position estimation and the methods to improve the existing problems are proposed respectively,and its applicability was analyzed.According to the difference of vector control and PWM_ON_PWM modulation control strategy,the switching start control strategy is analyzed,and the application scheme of different control strategy to Hall estimation is designed respectively.Based on MATLAB/Simulink environment,the control strategy model of BLDCM with different control strategies was set up,and the main technology was verified.The experimental platform of BLDCM control system based on TMS320F28335 is designed.To CCS as a development environment,completed the control system software program design and preparation.Experiments were carried out on the experimental platform,and a number of comparative experiments were made.Simulation and experimental results show that the design and improvement scheme can effectively improve the estimated accuracy of three phase Hall position signal on the motor speed and rotor position.The effectiveness and feasibility of the design scheme for BLDCM vector control and PWM_ON_PWM modulation control are verified.