The Study Of FNN Control On Direct Torque Control For BLDCM

In order to improve the response speed of Brushless DC Motor (BLDCM) control system and simplify its structure, a novel scheme is proposed in this paper. Direct Torque Control (DTC) scheme and fuzzy control strategy are combined in the new scheme. DTC has the advantage of fast response and simple system structure. However, its torque ripple is relatively high. The robustness of fuzzy control strategy can appropriately compensate the deficiency of DTC mentioned above. According to the error between torque and its reference value and the error variance ratio, the active time of space voltage vector can be solved by fuzzy logic to reduce torque ripple.Based on the mathematical model of BLDCM, this paper systemically proposed BLDCM DTC strategy and discusses Space Vector Modulation (SVM) DTC considering the features of BLDCM. The control scheme is designed in detail both in aspect of hardware and software. Fuzzy control and Neural Network are applied into the design and a space voltage vector list combined with them is built to get precise flux linkage signal. The BLDCM DTC system is simulated by MATLAB. Its hardware design uses TMS320LF2407 core. All function modules of program are stored in E2PROM of DSP, chiefly including the attributes self-adjusting fuzzy control scheme, BP neural network control scheme, PWM output, rotator position and speed detection and phase current measurement.Finally, experimental results show that the designed BLDCM DTC system has very good control performance.