A new LPF-based grid frequency estimation for the SOGI filter with improved harmonic rejection
Document typeConference lecture
Rights accessOpen Access
This paper proposes a new method for the estimation of the grid voltage frequency using a low-pass filter (LPF) approach. The estimated frequency is used to tune a second order generalized integrator (SOGI) filter commonly used for grid monitoring purposes and applications requiring parameter estimation from the grid. A first-order LPF is used first for the estimation that behaves identically to the reported normalized SOGI-FLL. A second-order LPF is proposed instead to overcome this circumstance. The behavior of this approach is dynamically analyzed and a linearized model useful for design purposes is derived. The behavior of the proposed system is checked with simulations, showing that the model matches well with the real system and has a smoother transient response to step frequency perturbations and also a better rejection to harmonic distortion than previous approaches.
CitationMatas, J., Martin, M., El Mariachet, J., Abusorrah, A., Al-Turki, Y. A new LPF-based grid frequency estimation for the SOGI filter with improved harmonic rejection. A: International Conference on Renewable Energies and Power Quality. "Renewable Energy and Power Quality Journal (RE&PQJ)". 2018, p. 722-727.