Research And Application Of BLDC Control Based On FPGA

The door is an important part of the high-speed train,which brings great convenience for people’s travel.The door controller is the control center of the door,which controls the motor to drive the door to complete a series of functions.China’s new "Revival" EMU train uses a brushless DC motor(BLDC)as a sliding door drive device.The quality of the BLDC control directly affects the life and property safety of passengers and the operating efficiency of the train.At the same time,with the advancement of semiconductor material technology,the switching frequency of power devices has been further increased.It puts forward higher requirements on the performance of the BLDC control system.In this thesis a brushless motor control system used in the door controller is implemented.The system is based on FPGA,controls BLDC through vector control algorithm,and uses the AXI4-Lite bus to communicate.The system can realize functions such as speed control,fault detection,and data acquisition.Firstly,according to the current research status of brushless DC motor and the sliding door controller,the advantages of controlling BLDC based on FPGA and vector control algorithm are shown.Then the functional requirements of the sliding door system related to BLDC control are analyzed.Secondly,based on the working principle of the BLDC,the vector control algorithm is chosen to drive BLDC,with hall sensor providing the information of the rotor position and Space Vector Pulse Width Modulation(SVPWM)converting the vector into the control pulses of the drive module.In addition,the Delta-Sigma modulator used to sample currents and the AXI4 bus used for on-chip dual-core communication are introduced.Then,the overall design block diagram of the system is given.The hardware circuits including the motor driving circuit and current sampling circuit were designed.And the implementation details of the VHDL code for the on-chip bus channel,ADS1204 decoding module,sine and cosine calculation module,vector transformation related modules,PID module,hall decoding module,sector judgment module,SVPWM module,three-phase break fault detection module and other modules are shown.Finally,the functions of each module of FPGA were tested by Modelsim simulation software to verify the correctness of the VHDL code.Joint debugging with the ARM program was completed on the actual high-speed rail door system,and the internal operating status of the motor was monitored by Portable Test Unit(PTU)software to verify the plug door system main functions related to brushless DC motor control.The experimental results show that the brushless DC motor control system designed in this thesis has high control accuracy and strong robustness,which improves the safety of the sliding door controller,and has a wide range of application,easy maintenance,and strong scalability.