Design and Implementation of a Teleprotection System with Digital and Analog Interfaces

Abstract

Safe and un-interrupted power transmission requires a widespread use of control and protection equipment to avoid fault propagation in power network. Protection systems have been used to detect faults and block them to strike the high voltage lines. The teleprotection system continuously sends commands to remote substation in case of fault identification. Thus, the reliability and transmission time are vital issues to avoid intolerable errors. Teleprotection systems are interface between protection system and communication equipment. This paper proposes a digital teleprotection system to connect to digital communication network. The system is based on line interfaces and in accordance to ITU-T G.703 standard (64kbps and 2Mbps rates). Furthermore, the system benefits from the analog interface and direct analog voice band or optical fibers connection using eight independent commands. The system supports 8 channels simultaneously while its transmission time is 4ms at most.