| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital current differential relay which can be used with no special correction with an opponent terminal current even if an existing communication medium is used or a new digital communication network is constituted. <P>SOLUTION: The digital current differential relay comprises a first calculation means 9 which A/D converts the electrical quantity of an own terminal and then processes it for vector component representation, a transmission means 10 for outputting the information of the own terminal containing the output current data of the means 9 (digital data signal), a modulation means which modulates the digital data signal outputted from the means 10 into a prescribed analogue data signal and transmits it to a current differential relay of an opponent terminal through a communication medium, a receiving means 13 which receives the analogue data signal transmitted from the opponent terminal and demodulates to an original digital data signal for reception, a second calculation means 14 which performs a current differential calculation using the current data of the own terminal/opponent terminal acquired from the transmitting means 10 and the receiving means 13, for detecting occurrence of accident inside a protected section, and a sampling synchronous control means 15 for controlling the sampling signals to be the same timing at terminals. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
