| 摘要 |
The present invention provides a ground protection relay device, in which a current limiting means having different resistance characteristics according to voltage differences between both ends thereof is constructed in a ground protection relay, and particularly placed between the negative bus of a rectifier and the ground. Therefore, in a normal operating state, the current limiting means exhibits high resistance characteristics, thus limiting a leakage current to a reference level or less, while, at the time of a ground fault, the current limiting means exhibits small resistance characteristics, thus enabling a ground fault current having sufficient value for measurement to flow through the current limiting means. Further, the present invention provides a ground protection relay system and method of controlling the same, which determines the occurrence of a ground fault by measuring the value of ground fault current flowing through the current limiting means, and determines a faulty feeder by comparing variations in currents flowing through feeders with variation in ground fault current for the same period of time. |
