| 摘要 |
Method and device for range limitation and direct tripping for protection in the case of a fault on a power transmission line located between two stations (P, Q) with a traveling wave model located in one of the stations (P), which travelling wave model, with the said of measured currents and voltages in the station, calculates the voltage distribution at a number of control points along the line. The range of a protection device is indicated as the distance between the measuring station and that control point for which a voltage difference ( delta u) becomes equal to zero. The voltage difference consists of the difference between the absolute value of a voltage difference ( DELTA u), formed as the sum of a voltage value (U sec ) calculated with the travelling wave model for the control point at a certain time, and the corresponding voltage value (U min ) one half-period earlier and the absolute value of the latter voltage value. When the voltage difference becomes greater than zero, a direct tripping is initiated. |
