Phase locked loop with fast tracking over wide stability range under grid faults

This paper introduces a PLL characterized by fast dynamics, wide stability range and minimal deviations. The proposed PLL is based on a frequency adaptive filtering stage to minimize the frequency and phase deviations under unbalanced conditions and harmonic distortions. Furthermore, a simple mathematical formula is introduced to modify the conventional synchronous frame based PLL to provide more stabilization points for the PLL. The advantages of the proposed PLL are verified through simulations.