Patent ID: 6731655
Filing Date: 2004-05-04
Classification: H02H

Abstract:
A current differential relay device for sampling the currents at a first terminal and a second terminal of a power system at the same timing maintaining a predetermined period and for executing the operation for current differential protection by using a first current value sampled at the first terminal and a second current value sampled at the second terminal at the same timing and transmitted with a fixed frame unit that is set depending upon the sampling period, said current differential relay device comprising:setting means for setting the number of digital transmission bits in said fixed frame to an integer which is not larger than a value of a rate of the bits/sampling frequency when there is no multiple relationship between the rate of transmitting the bits for transmitting the sampled currents in a digital form and the sampling frequency for sampling the currents; and dummy bit interpolation means for selectively inserting dummy bits among the fixed frames related to the digital transmission in order to maintain synchronism between timings of the sampling and the data transmission.