The Design Of Control Device Applied To Brushless DC Motor Based On NiosⅡ

The development of automatic control theory,technology of power electronics, computer control technology and technology of embedded system powerfully supports the progress of motor control system both theoretically and technically.Compared with conventional brush DC motors,the brushless DC(BLDC) motors adopt the electronic commutation instead of brush machinery commutation,which can greatly extend the service life of motors and enhance control system's stability.CPUs in line with design's needs can be made by the SOPC(System On a Programmable Chip) technology based on Niosâ…¡soft core and also the appropriate peripherals,memories and interfaces can be chosen using this technology.So a controller in line with actual needs,which will be very small,can be developed on a simple chip.In combination with the above mentioned characteristics,this kind of control system presents a good application prospect in the industrial and civil territory even in the servo domain.In context of those mentioned above,this article introduces the brushless DC motor's principle of work and the brushless DC motor's PWM modulation,and completes the SOPC design of the brushiess DC motor control system using Niosâ…¡soft core.The hardware system includes control circuit which taking FPGA as the core and the three-phase full bridge inverter circuit used to drive the motor,having done the massive experiment to the FPGA auxiliary equipment's choice and inverter circuit's design.This system's control software includes using the VHDL language to generate the IP cores of the hall decoder module,the motor control module and PID regulator module in the Quartusâ…¡and the configuration of the soft microprocessor core and the periphery IP cores and the design of the embedded system software in the SOPC Builder. It's a key to make some discussion on the realizing of the PID regulator in FPGA.This article in view of the inverter circuit's different working ways,utilizes the PWM technology to realize speed control,separately makes experiment of the full bridge and half bridge modulation,and has carried on the analysis of the experimental result.The experiment indicates that the brushless DC motor control system performs in a very good condition,debugging is convenient,switch noise is small,could be updated easily,and has provided the foundation for the further research work and other engineers for reference.