Estimation of single-phase grid voltage fundamental parameters using fixed frequency tuned second-order generalized integrator based technique

This paper proposes a robust technique for accurate estimation of single-phase grid voltage fundamental amplitude and frequency under harmonics. The proposed technique relies on a quadrature signal generator based on a fixed frequency tuned second-order generalized integrator. A differentiation filter is used to estimate the fundamental frequency from the instantaneous phase angle derived from the generated orthogonal voltage systems. The estimated fundamental frequency is then used to obtain the actual fundamental voltage amplitude from the orthogonal voltage systems. The proposed technique does not rely on interdependent loops offering stability and easy tuning process. The technique can reject the negative effects caused by the presence of the harmonics. Experimental results are provided to validate the performance of the proposed technique.