Design Of DC Brushless Motor Controller And Its Application In Drum Washing Machine

With the development of economy and the improvement of people's energy-saving awareness,green and environmentally friendly home appliances have been greatly welcomed.As a daily cleaning tool,the drum washing machine not only saves energy and electricity,but is also low-carbon and environmentally friendly.The operation of the drum washing machine mainly depends on the operation of the control system,and the quality of the control system directly determines the overall performance of the drum washing machine.The DC brushless motor control system can meet the requirements of high energy efficiency and low noise of the drum washing machine,it is widely used in the drum washing machine due to its simple structure,long life and good speed adjustment performance.The dissertation introduces the structure and operation principle of the brushless DC motor,and builds the mathematical model of the brushless DC motor,and gives the mathematical equations.The principle of vector control is introduced in detail,by comparing different vector control strategies,vector control is used to decouple the stator current of the motor,and the coordinate system is transformed using Clark transformation and Park transformation.The principle and implementation method of space vector pulse width modulation control(SVPWM)are analyzed,the SVPWM algorithm generates high-precision PWM waves,which provides a theoretical basis for the software design of the control system.The dissertation completes the hardware design of the DC brushless motor controller applied to the drum washing machine based on ST's STM32 chip,the system switching power supply design with VIPER12 A chip and TPS54331 chip as the core is realized,and the interference problem of the motor control circuit to the STM32 core circuit is solved.The hardware design circuit mainly includes STM32 peripheral interface,IPM driver,current detection,hardware protection,position detection,function selection and power supply design,and other functional modules.And realized the schematic design and PCB design,tested the hardware circuit and basic unit functions,and completed the construction of the hardware platform.Based on the hardware platform,the vector control(FOC)algorithm is used to complete the software design of the rcontrol system.The main functions of the software design include the main program,A / D interrupt,speed detection,SVPWM algorithm,PI adjustment and laundry function processing Etc.,and adopts PI double closed loop control to ensure the reliability and stability of the system.At the end of the thesis,the control system was tested,and a brushless DC motor with a rated power of 145 W and a rated voltage of 310 V was used as an experimental motor for testing,repeated experiments on the motor speed control.The experimental results show that the controller controls the motor to run stably and control efficiency is high,which meets the expected design requirements.