Abstract—This paper presents multi level inverter fed Permanent Magnet Brushless DC Motor (PMBLDCM) with a simplified voltage control technique. It is based on the “indirect position sensing,” which was justified by the observation that position sensing came indirectly from voltage and current waveforms. The switching angle for the pulse is selected in such way to reduce the harmonic distortion. This drive system has advantages like reduced total harmonic distortion and higher torques. PI, Fuzzy and Hybrid ( Fuzzy and PI) controllers are discussed. Closed loop simulation response is obtained for PI, Fuzzy and Hybrid controller with a disturbance in the input source. The conventional circuit is improved by introducing Hybrid Controller. In Industrial application the physical integration of Hybrid controller in the motor body itself is able to make them most suitable for low power (0.5hp) blowers and low power (50W) tube axial fans for cooling the electronic equipment. The performance of the PMBLDCM system is simulated and implemented. Simulation results of these systems are presented and the performance measures are compared. The simulation results with Hybrid controller indicate improved performance. The experimental results are compared with simulation results.

Index Terms—Three level inverter, FLC, PI, Hybrid, trapezoidal back emf, PWM, , Sim Power systems.

Cite: Narmadha T. V. and Thyagarajan T., "Fuzzy Logic Based Position-Sensorless Speed Control of Multi Level Inverter Fed PMBLDC Drive," Journal of Advances in Information Technology, Vol. 1, No. 1, pp. 52-58, February, 2010.doi:10.4304/jait.1.1.52-58