Design and simulation of new method of a sensorless control of BLDC motor by usying of speed and rotor position method

This paper describes a new position and speed observer, for BLDCPM1 motor drive sensorless control, based on the line-to-line PM flux linkage estimation. Line-to-line PM flux linkage can be estimated based on measured phase currents and line to line voltage. The zero-crossing of the line-to-line PM flux linkage occurs right in the middle of two commutation points, which is used as a basis for the position and speed observer. Even if the proposed observer relies on the fundamental model of the machine, a safe starting strategy under heavy load torque, called I-f control, is used, with seamless transition to the proposed sensorless control. The I-f starting method allows low- speed sensorless control, without knowing the initial position, and without machine parameters identification. Digital simulations and experimental results are shown, demonstrating the reliability of position and speed observer for BLDC PM motor sensorless control operation.