A new software-based method for rotor angle calculation

In this paper, a new method for rotor angular position calculating is proposed. This method uses an improved angle tracking observer. Initial angle of the observer is estimated by the appropriate sector determination. In this scheme, according to the amplitude of sine, cosine, sin(θ-45) and cos(θ-45) signals, the range of [0-2π] is divided into eight sectors. Considering to resolver´s output signals, the rotor angle´s sector is determined. In the determined sector, the initial angle of rotor is estimated by the signal with the smallest amplitude. Then, by a phase locked loop, initial estimated value of rotor angle is driven to the actual value. Proposed method has been successfully simulated in MATLAB/SIMULINK, and the findings emphasize the accuracy and validity of this scheme.