Sensorless control of BLDC motor using flux linkage based algorithm

Abstract

The performance of Conventional sensorless back-emf detection techniques for BLDC Motor is poor at low speeds, since at zero and low speeds the magnitude of back-emf is very less. This causes failure of zero crossing instant detection. This paper presents a new Sensorless Control Technique for BLDC motor drive to estimate the rotor position accurately even at zero and low speeds. A new algorithm has been developed to estimate the rotor position based on the prediction of stator flux linkages. The main advantage of the proposed technique is that the flux linkages are independent of the speed. For starting of the motor an open loop starting method was adopted. By implementing this technique the Meta heuristic digital signal control systems like PWM/ADC, PLL are avoided in order to make motor control easy and economical. To verify the accuracy of the proposed technique it is compared with existing hall sensors controlled BLDC drive operation. The validity of proposed scheme is verified through Simulation.