Neutral point nonlinear resistor grounding protection system and reliable line selection device

The invention discloses a neutral point non-linear resistance grounding protection system and reliable line selection device, which comprises a high-impedance grounding transformer GJBC, an execution unit, a three-phase phase-control quick circuit breaker DL2, a zero sequence current transformer LH, a voltage transformer YH, an instantaneous current injection method line selection controller, a fault processing controller and a full-voltage monitoring and fault recording controller, the invention relates to the technical field of electrical engineering. According to the neutral point nonlinear resistor grounding protection system and the reliable line selection device, rapid line selection and fault loop locking can be carried out by injecting instantaneous large current into a circuit, the purpose of rapidly and safely carrying out neutral point grounding protection is well achieved, the safety is greatly improved, grounding fault query is simple and rapid, and the reliability is high. The risk of short circ