Research And Design Of Sensorless Brushless DC Motor Controller For Range Hood

With the rapidly development of the current technology and economy and the promotion of urbanization,more and more range hoods are used in the kitchen.It can immediately exhaust the harmful gas caused by cooking to protect the indoor air from pollution.Considering the environment condition of the range hood,it requires small noise,high efficiency and less installation space.As the power unit of the range hood,the selection and control mode of the motor play an important role on its work.In recent years,brushless DC motor with its unique advantage,has gradually been favored by people.However,the traditional square wave drive mode still has many weaknesses,such as large torque ripple,big noise,poor speed performance,low efficiency.Therefore,in this paper,focusing on the brushless DC motor,the sensorless rotor position detection method and drive control strategy are researched.A drive control device is developed and the experimental results are given.The main works done in this paper are as follows:(1)This paper summarizes the research background of the range hood.It introduces the latest research achievements and the research direction of the domestic and foreign scholars in this field.The vector control method of the motor is been discussed,and also been analyzed of the fundamental difference from the square wave control mode and the reason of its high efficiency.By combining the actual needs of the range hood,the overall architecture of the control system is proposed.(2)It introduces the structure and working principle of the brushless DC motor,and establishes the static and dynamic mathematical model and and carries out the MATLAB simulation.Several sensorless position detection ways are analyzed and compared.Aiming at the deviation of the rotor position estimated by the Hall sensor due to the acceleration or deceleration of the motor in the sensor vector control system,this paper presents a rotor angle gradient solution,to avoid the chattering when commutation.(3)Considering the particular using environment of the the research object,there is the possibility of Upwind start and load change.The traditional method tends to dither or failure.Therefore,this paper presents a variable inductance method,which can get the rotor position before starting.In general,the motor can be started more quickly.(4)The brushless DC motor control system is designed,which based on the STM32f130 RB.It completes the power module,inverter drive module,hardware protection module,key communication and other external interface module design,and writes the sensor square wave control,sensor vector control and sensorless vector control applications software.A prototype controller is developed and carried out.The experimental results show that the proposed drive control strategy makes the motor torque smaller ripple and lower noise to meet the requirements of the hood drive system.So that it could verify the feasibility and effectiveness of our method in this paper.