Abstract： |
The invention belongs to electric power system field, in particular to a single-phase grounding failure relay protection method based on a negative sequence reactance relay. The method includes: Measure the circuit's failure phase voltage Uphi, phase current Iphi, zero sequence voltage U0, zero sequence current I0, and negative sequence current I2 at the installation place of transformer station as the input values; calculate the residual voltage phasor of the failure point through measuring voltage, measuring current, negative sequence current at the place of protection installation, and circuit impedance angle; constitute the action voltage phasor Uop through measuring voltage, measuring current, residual voltage phasor of failure point, and impedance value within the scope of circuit protection; calculate the angle that the action voltage phasor Uop leads the negative sequence current iU2. If the angle is within the range of [180 DEG, 360 DEG], the protection action sends a signal of tripping operation; contrarily, the protection will not take any action. The method is suitable for the electricity transmission side of ultra/super high voltage electric circuit, particularly ultra/super high voltage heavy load electric circuit. The invention can meet requirements for selection, reliability, sensitivity, and speediness of relay protection. |
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