BRANDT CLOSED LOOP OPTICALLY COUPLED BLDC MOTOR DRIVE SYSTEM OPERATIONAL SUMMARY

摘要

The Brandt Closed Loop Optically Coupled BLDC Motor Drive System is designedto maximizethe performance of the motor by harvesting the energy losses associated withthe unused backEMF. The system employs two distinct feedback loops. One loop continuallygathers rotorposition information to determine the current speed and adjusts the width ofPWM signal viaoptical coupling that controls the switching of the field windings. This inturn increases ordecreases the motor speed. A second feedback loop gathers the back EMF fromthe field,rectifies it and adds it to the DC source that sets the signal magnitude ofthe PWM signal appliedto the field or is applied directly to motor output. This adjusts the motorspeed, output and thusefficiency. Therefore, system performance is optimized for each state ofoperation. In addition tothese automatic control loops, the system also includes three manualadjustments that provideadditional flexibility and control over motor operation.