New algorithm for grid synchronization based on Fourier series

This paper presents a new digital open loop architecture as an alternative to Phase locked loops (PLLs) for grid synchronization. The system calculates in real time the Fourier coefficients of the input signal fundamental component using a heterodyning algorithm. Once the fundamental components are calculated the system can reconstruct the input fundamental signal and calculate its phase angle, frequency and amplitude. The measuring process of the Fourier components require to hlter even harmonic components internally generated; this process is made with a moving average comb filter (MVA) tuned for these even harmonics. The performance of the system is demonstrated with experimental results.