Generator injection-type stator ground protection method applicable to single-point and dual-point grounding systems

For single and two-point grounding system of a generator stator ground protection injection method, the protection device detects the generator terminal current transformer CT secondary side current, three-phase current calculated effective value signal: Ia, Ib, Ic ; protection breaker GCB generator means for detecting the position of the contact signal TWJGCB Tab; TWJGCB = 0 when the signal indicates GCB in engagement position; when the signal TWJGCB = 1, represents GCB in Tab; master protection detecting means becomes a low pressure side disconnector contact signal TWJSW division bit position of the grounding transformer; TWJSW = 0 when the signal indicates isolation switch is in engagement position; when the signal TWJSW = 1, represents the divided bit isolation switch; conditions for performed: by state and determining two calculation methods, the protection device may be implemented flexibly adapted to a generator - stator ground protection injection transformer unit and the two single-point grounding system.