Design And Application Of Brushless DC Motor Control System In Electric Skateboard Vehicle

With the development of motor technology and control technology,electric scooter is more and more popular.The electric scooter shall have the characteristics of fast starting response,stable operation and good climbing performance.At present,most of the electric scooters are driven by brush DC motor.Although the brush motor is cheap,its conversion efficiency and output power are low.The installation volume of motor and control system is large.The BLDCM is a new type of motor which integrates motor and power electronics.The BLDCM system operates through the joint action of motor and auxiliary device.It uses the characteristics of power electronic power conversion device to replace the traditional mechanical electric brush for steering control system,so the efficiency of the BLDCM is high,the volume is small,and the service life is long.But its cost is high and its control performance is weak,so it is necessary to design a control system of BLDCM with high cost performance and stable control performance for the development of electric scooter.This paper mainly takes the hub brushless DC motor for electric skateboard vehicle as the control object,and the R7F0C009 single chip microcomputer as the control circuit.The single chip microcomputer collects the comparative level and motor feedback signal,and controls the brushless DC motor through software programming.The control system of Brushless DC Motor is established.The details of the study are as follows:(1)This paper introduces the current situation and development of electric scooter industry,analyzes and compares the control mode of BLDCM,and expounds several main control technologies and starting modes of BLDCM without position sensor.(2)The working principle and mathematical model of BLDCM are analyzed.Based on the end voltage anti-electromotive force detection method is studied in detail..Because the back electromotive force method requires a special start-up mode,the start-up mode of the control system in this design is determined to be three-stage start-up method by comparing the realization mode and hardware circuit.(3)In order to realize the control method without position sensor,the hardware experiment platform needs to be built.Hardware design of the system.It mainly describes the analysis and design of six modules.Taking r7f0c009 as MCU control,the input of external key,speed regulation and brake handle,as well as the feedback signal from the output end are collected,and the duty cycle of PWM wave of MOSFET in inverter bridge is controlled to realize the speed regulation of BLDCM..(4)Under the software development environment of hew: high performance embedded workshop,the six modules of the system of BLDCM,such as start stop program,closed-loop operation program,zero crossing program,dot matrix display program,keyboard program,are designed and programmed,and then the program is debugged until the conditions are met.(5)Establish the verification platform of the control system of BLDCM and test the feasibility of the control system.Then the control system module is assembled on the scooter to test the stability of the application of the BLDCM control system.The final test shows that the designed control system can meet the design requirements of the control system of the BLDCM on the electric scooter,all functions respond in real time,realize normally,and the whole vehicle can run stably for a long time.Compared with other models,the starting performance,acceleration ability,climbing ability and endurance ability have been improved,with high promotion and application value.