Sensorless vector control for BLDC machine

Abstract

Vector control of electrical machines deliver better performance and efficiency when compared to traditional driving methods, however they demand constant precise angular position measurement through sensors that add cost to the system. In this work the vector control of the BLDC machine is investigated, considering the added drawbacks given by the trapezoidal waveform of the BEMF. Position estimation is given through the analysis and adjustment using PLLs of the BEMF estimated by means of a Kalman filter, then Field Oriented Control is applied with the dqx coordinate transform in order to achieve high efficiency and low torque ripple. Simulations of the developed system demonstrate the effectiveness of the estimator, with low estimation error, allowing for good dynamic response of the controller.