Improved BLDC motor performance with digitally filtering back-EMF using dsPIC30F microcontroller

This paper present design and implementation a digital filter for a back-emf sensorless control of a brushless permanent magnet (BLDC) motor using the dspic30F microcontroller. Normally, the back-emf signal has noise from the driven sector coupled onto the signal. A PWM signal is used to vary the Voltage, and therefore the speed of the motor. So it is difficult to detect the zero-crossing event due to the coupled PWM noise. A filtered back-emf signal can be generated that looks more like ideal signal and then it is easer to detect zero-crossing event. we show that the problem related with low and high speed can be overcome using dspic30F6010a microcontroller peripheral. The design of digital filter and simulation result is perform using MATLAB software.