Method and device for online monitoring of high voltage circuit breaker

摘要

The invention relates to a method for measuring a condition of at least one circuit breaker (2) in a high voltage system (1), wherein the at least one circuit breaker (2) having a contact pair (24, 26); comprising the steps of:- injecting a transient test signal through a first coupling means (53) into a first terminal (21) of each of the at least one circuit breaker (2);- detecting a resulting transient test signal through a second coupling means (54) at a second terminal (22) of each of the at least one circuit breaker (2);- detecting, during an operation of the circuit breaker (2), the instant of physical contact of the contacts of the contact pair (24, 26), wherein the instant of contact is detected by a change of the amplitude level and/or phase value and/or noise level of the received test signal, when setting the at least one circuit breaker (2) to close or to open, and- determining the condition of the at least one circuit breaker (2) depending on a time delay defined by the instant of contact and by a further instant,wherein the further instant corresponds to an instant of an additional change of the amplitude level and/or phase value and/or noise level of the received test signal during the operation of the at least one circuit breaker (2).