Phase Locked Loop technique based on sliding DFT for single phase grid converter applications

The single-phase grid-connected converter is a key element in the integration of renewable energy sources to the grid. Accurate and instant estimation of grid voltage attributes like amplitude, phase angle and frequency is essential for the successful operation and control of such power converters. This paper presents a Phase Locked Loop (PLL) for tracking these parameters. The proposed technique employs Sliding Discrete Fourier Transform (SDFT) for phase error detection. Further, the method is insensitive to harmonic distortion and robust against voltage variation, phase jump and frequency drifts. The effective performance of the proposed method is demonstrated with simulation studies performed in MATLAB environment.