Kabushiki Kaisha Toshiba

Yokohama National University

Toshiba Energy Systems & Solutions Corporation

Kazuto Fukushima

Hideaki Sugiura

Tsutomu Matsumoto

Katsuhiko Sekiguchi

Shigeki Katayama

Akira Kawarada

Masamichi Saga

Akinori Hirose

According to an embodiment, the transmission processor of the master terminal includes a sending/receiving processor which sends a synchronization request demanding packet to a particular slave terminal and sends a synchronization reply packet when receiving a synchronization request packet from the slave terminal that has received the synchronization request demanding packet, and a synchronization controller which calculates a synchronization band from the time of the receipt of the data packet and from time information added to the received data packet to determine a synchronization state and which adjusts a correction amount in accordance with the synchronization state and sends an internal timing correction command to the timing generator.

Synchronization control system

According to one embodiment, when sending a transmission target main data, an authentication-tag generator unitgenerates an authentication tagby using a main dataand a key datastored in a key-data storage unit. A transmitter/receiver unitadds the authentication tagto the main datasends as a transmission data. When receiving the received data, the transmitter/receiver unitdivides the received data into a main dataand an authentication tag. The authentication-tag generator unitgenerates an authentication tagfor comparison. A received-data authentication unitdetermines whether or not those the received authentication tagand the authentication tag for comparisonmatch with each other. A different key data is used every time upon the authentication-tag generation and use time of each key data during a set period is restricted.

Protective-control measuring system and device and data transmission method

Provided is a high-precision and highly functional digital protective relay device and a data transmission device for a digital protective relay device, by enabling transmission of large amounts of system electrical quantity data. The data transmission device for a digital protective relay device, the transmission device comprising: an analog/digital conversion portion, which, after sampling a system electrical quantity signal acquired from an electric power system at m times the fundamental frequency f0 (m&#x3e;12) thereof, performs conversion into n-bit digital data (n&#x3e;12); a data processing portion, which converts m sampling data of n bits with frequency m&#xb7;f0, obtained by the analog/digital conversion portion, into k sampling data with frequency k&#xb7;f0 (k&#x2266;m) at or below the former frequency; and a transmitting portion, which transmits k sampling data obtained by the data processing portion to another protective relay device in a prescribed transmission format.

Digital protective relay device and data transmission device for the same

Growing community of inventors

Aoba-ku, Japan

Kazuto Fukushima