Stator ground protection based on the third harmonic transimitted and zero-sequence voltage changed greatly when 210 MW gas-generator was working with 191 MW load.The analysis of sampled data indicated single-phase ground is impossible.Being considered of fundamental zero-sequence voltage sensitive setting
the faction plate of the protection exited to avoid cutting machine accident of the protection malfunction.Measures of improving the reliability of generator stator ground protection action was put forward based on the defect of TV break blocking
the determination of protection principle
calculation of variable fixed coefficient and TV grounding of the primary winding.