An instantaneous phase angle estimation algorithm for power converters under distorted utility conditions

This paper describes an algorithm for phase angle estimation based on symmetrical sequence components. The algorithm uses the recursive weighted least-squares method to estimate the fundamental component of the positive and negative sequences. The phase angle is estimated at each iteration from the fundamental component of positive sequence. The proposed method eliminates low order harmonics and dc offset in the sampled variable. The operation of the algorithm under this distorted utility condition is presented. Simulation and experimental results validate the theoretical approach.