| 摘要 |
An apparatus (302) for detecting a fault in a high voltage direct current, HVDC, power transmission system (304), the system comprising an internal part (306) and an external part (308) for carrying direct current, DC, where the internal part comprises at least one HVDC transmission or distribution line (310) for carrying direct current, and the external part is separated from the internal part by means of at least one inductor (312), the apparatus comprising current determination means (330) for determining the current carried by the HVDC transmission or distribution line; voltage determination means (334) for determining the voltage at a first location (336) of the HVDC power transmission system; impedance determination means (342) for determining the impedance based on the determined current and voltage; derivative determination means (344) for determining the derivative of the impedance; and fault detection means are arranged to detect a fault on the internal part at least partially based on the derivative of the impedance. An HVDC power transmission system comprising such an apparatus. A method for detecting a fault in the above-mentioned high HVDC power transmission system, the method comprising the steps of: determining the current (502) carried by the HVDC transmission or distribution line; determining the voltage (502) at a first location of the HVDC power transmission system; determining the impedance (504) based on the determined current and voltage; determining the derivative of the impedance (506); and detecting a fault (512) on the internal part at least partially based on the derivative of the impedance. |
