The Study and Realization of BLDC Motor Control System

　　The Study and Realization of BLDC Motor Control System
　　Brushless DC Motor with permanent excitation is a new special motor developing in recent years,which changes its phases through the electronic units.It is a production which includes the feature of mechanics and electrical engineering.This new motor has not only the same good characteristics of speed control,high efficiency and high rise torque as traditional DC motor, but also the same good characteristics of simple structure,stable reliability,easy maintainance of AC Motor Brushless DC motors.The topic of this thesis, which is based on the driver of BLDC Motor comes from enterprise project of Special Motor Institute.Consequently two drivers are designed and compared.First of the article many interrelated reference both in China and abroad has seeked,neodymium standard state what’s more the basic theory is introduced and the running mode is analyzed and confirmed.The first driver,
　　which has the feedback unit of both hall sensor and encoder sensor, is based on the special IC MC33035.Meanwhile MOSFET is used as the power switch part.In the driver there has the function of Forward/reverse running mode,close loop control,over-current protection and on so.In addition,the numeral given value and numeral show is realized by single chip C51,MAX7219 and AD667.The second driver is based on the PIC 18F4431,which is used specially for the motor control. In the second driver there has the function of digital PID contro,speed and current feedback loop. Moreover, encoder sensor is used for rotor position feedback and IGBT is used for power switch part.To protect IGBT, the GAL chip is used to avoid connecting positive terminal and cathode terminal.There are two set of program.The first program is designed for the two-two PWM running mode without the given value.In this case the torque ripple is obvious.In the second program the given value http://www.999magnet.com/products/112-neodymium-standard-state is added so that the torque ripple is decreased.After designing the two drivers, many experiments are done and the experiment data is analyzed.Finally we draw some conclusions.The conclusions are as follow:With the comparation and analysis of the two drivers, the driver based on the special chip MC33035 is cheap but it can’t afford with a high precise feature, consequently it can just be used for the common environment.The driver based on PIC18F4431 has a better running feature and it can meet a higher requirement.