High order repetitive control has been introduced to overcome performance decay of repetitive control systems under varying frequency of the signals to be tracked/rejected or improving the interhamonic behavior. However, most high order repetitive internal models used to improve frequency uncertainty are unstable, as a consequence practical implementations are more difficult. In this work a stable, second order odd-harmonic repetitive control system is presented and studied. The proposed internal model has been implemented and validated in a shunt active filter current controller. This high order controller allows dealing with the grid frequency variations without using adaptive schemes.