REN (Rede Eléctrica Nacional) operates Portugal’s national transmission grid, delivering power to nearly 6.2 million consumers over 9000 km of high-voltage infrastructure from generation sources that include coal, natural gas, fuel oil, diesel, water, sun, biomass and waste.
The northern region of Portugal is a key part of this transmission grid because it contains important links to European power networks via Spain, as well as most of the country’s hydro generation. For this reason, REN opted to replace aging protection and control systems in the region’s important Vila Fria and Torrão transmission substations with Hitachi Energy's substation automation systems (SAS).
The goal is to help modernize the transmission grid with the latest Hitachi Energy substation technology available, including IEC 61850 substation communication solutions with full parallel redundancy protocol (PRP), which enables substation systems to overcome the failure of a link or switch in zero switchover time.
The IEC 61850 standard defines the Ethernet technology for substation automation communication, including protection and control functions. It enables intelligent electronic devices (IEDs) from different manufacturers to “talk with each other” and thus operate with each other.
PRP helps facilitate this interoperability – with respect to redundant communication – between protection, measurement, and control devices from different manufacturers.
REN is in the process of improving grid conditions in northern Portugal in order to better integrate new hydro and wind power generation in the region, without affecting the existing international power connections with Spain and Europe.
For the Vila Fria and Torrão substations, REN needs a reliable automation system with high redundancy for intelligent electronic devices (IEDs), substation automation systems (SAS), and the local communication network (hot-standby, in which both primary and backup systems run simultaneously in real-time so both systems have identical information, and PRP).
In addition, the substations had to remain in operation as Hitachi Energy installed the new automation systems on-site. In order to do that, Hitachi Energy had to find an effective way of installing the new SAS bay-by-bay in order to maintain the coexistence of the old and new protection and control systems.
For this project, Hitachi Energy is providing a variety of SAS components and services, including its IED 670 series protection, control, and monitoring devices; AFS switches to facilitate intercommunication between Ethernet devices, and enable operators to configure, manage, and monitor local area networks for greater data control and secure access; MicroSCADA systems; cubicles; engineering, factory acceptance testing (FAT) and commissioning.
Hitachi Energy has done business with REN since the 80s and has over the years delivered complete new automation systems for both new and retrofit transmission substations.
For example, Hitachi Energy supplied the utility’s first IEC 61850 system, installing it in 2007 at the 400/220 kilovolt (kV) Lagoaça substation, which is responsible for essential interconnection points with the Spanish grid at the 400 kV voltage level. REN wanted a standardized SAS architecture that offered the same network topology and overall arrangement, independent of the supplier.