| 摘要 |
PROBLEM TO BE SOLVED: To provide a device and a method for detecting the leak of a DC circuit, which are simple and low-cost as compared with conventional ones.SOLUTION: Leak detection devices Fa, Fd detect the leak of a DC circuit 30 connected to an AC circuit 10 via a power converter 20. The AC circuit 10 is connected to an upper-level power system 1 via a transformer 2 having a grounded neutral point 5n at the secondary side. AC current sensors Fa, Fd are provided in some places of current paths between the neutral point 5n of the transformer 2 and an assumed ground fault point of the DC circuit 30, and include AC current sensors 41, 43P, 43N and determination parts 42, 44. The determination parts 42, 44 determine the leak of the DC circuit 30 on the basis of current components having the same frequencies as those of AC voltages generated at the DC circuit 30 side by the conversion operation of the power converter 20, from among the AC currents detected by the AC current sensors 41, 43P, 43N. |
