In order to improve the operation reliability and stability of 1 000 MW generators, as well as prevent the excitation system from the abnormal away, which may lead to the wrong tripping operation of generator protection, the matching between the setting value of generators field loss protection and the limiter parameters of low excitation in excitation regulator, the matching between the setting value of generators over excitation protection and the limit parameters of voltage/frequency in excitation regulator, as well as the matching between the over current protection of generator stator and the limit parameters of stator current in excitation regulator are analyzed in this paper, on the basis of engineering examples.