| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground system for avoiding impairment of an apparatus incident to a significant variation in the input voltage or current of a power signal, due to a harmonic or a pseudo DC.SOLUTION: A continuous ground system for use in an AC system including a transformer includes a switch assembly 202 connected between the neutral 10 of a transformer 12 and the earth 14. The switch assembly has an open position and a close position, a route between the electrical connection and the transformer neutral via the switch assembly is interrupted at the open position, and a route for connecting the electrical connection and the transformer neutral via the switch assembly is established at the close position. The switch assembly is in the state of close position during normal operation of an AC electric device. The ground system further includes a control circuit having a sensor configured to operate the switch assembly to the open position, when detecting that any one of the harmonic signal of one or more power phases of the transformer, or the DC current between the transformer neutral and the earth has a predetermined threshold.SELECTED DRAWING: Figure 2 |
