| 摘要 |
<P>PROBLEM TO BE SOLVED: To facilitate evaluating whether protective relay operations are sound as a whole, even if a current transformer is saturated. <P>SOLUTION: A current detected by a current transformer 15 for detecting a current flowing in a power electric wire is input to a protective relay 16, and an operation signal is output to a trip circuit 17 when an accident is determined by accident determination. When the current transformer 15 of a protective relay system for opening a circuit breaker 13d according to a trip command from the trip circuit 17 has such characteristics that it is saturated to the maximum accident current, a simulated saturation accident current simulating a detection signal of the current transformer 15 when the current transformer 15 is saturated to the maximum accident current is input to the protective relay 16. Operation time from an input of the simulated saturation accident current to the protective relay 16 to an output of a trip command from the trip circuit 17 is measured, and it is evaluated that the protective relay system is sound when the operation time is within a prescribed predetermined time. <P>COPYRIGHT: (C)2011,JPO&INPIT |
