Study Of Ripple Torque For Brushless DC Motor And Its Simulation

Because of its eminent performance, the Brushless DC Motor (BLDCM) has been broadly applied. Since BLDCM has rather ripple torque in operation with low speed, the reasons that give rise to torque ripple on BLDCM have been described in this paper. The methods for suppressing the torque ripple are analyzed respectively. How rejecting ripple torque which is generated from stator windings inversion and cogging torque are analyzed in detail. Moreover the system control and BLDCM?s structure adopt fuzzy PID control and Soltless BLDCM.For using TMS320LF2407 as control slug, all function modules of program are stored in E2PROM of DSP, chiefly including fuzzy PID control scheme, PWM output, rotator position and speed detection and phase current measurement. The all-digital control system based on DSP increases the real-time performance of system and realizes accurately control, besides simplify circuit design.Finally, base on analyzing the mathematic model of Brushless DC Motor, this paper establishes a simulation model of BLDCM control system. By adopting different kinds of control algorithms, digital fuzzy PID control system and system which use traditional PID control are compared. Experimental results show the improved scheme which has high dynamic and static performance, fuzzy PID controller is superior to the traditional PID controller. It is approved that control theory with digital fuzzy PID control can reject effectively ripple torque of BLDCM.