FW-5, FW-50, Star coupler
IEC 60870-5-104, IEC 60870-5-103
The key task of Westfalen Weser Netz GmbH is to provide a safe, reliable and efficient supply of electricity, natural gas and water to industrial, commercial, farming and residential customers. The grid area of the regional supplier extends across an area of 6,400 km² spanning two federal states in the high-growth regions of East Westphalia-Lippe and southern Lower Saxony. Westfalen Weser Netz based in Paderborn is a subsidiary of Westfalen Weser Energie GmbH & Co. KG, which is a public-domain company owned by 48 local communities and districts in its grid area. With an efficiency factor of 100% in the electricity sector and down times of under seven minutes in 2014, the companypresents a convincing case.
Achieving such outstanding results demands highly competent staff but also requires modern technology that is up to the challenge of the constantly increasing number of renewable energy feed-in points. At larger transformer stations and distribution stations, the company has relied on SAE technology for its telecontrol systems for the last five years following many years of positive experience with the equipment in the natural gas and water supply sectors. It is largely a case of making the various voltage levels at the transformer stations and switching stations remotely controllable. The SAE FW-50 remote terminal unit is used as the standard unit and up to three size BGT-L module racks may be combined in larger energy plants. The Siemens protection and control units are generally linked via fibre-optic cable, with the SAE mcPS1 serving as media converter in combination with the mcFO. Data communication between protective equipment and telecontrol unit takes place using the IEC 60870-5-103 protocol. Process points that cannot be acquired in that way are implemented by means of digital and analogue modules. Communication with the Siemens Spectrum Power control system normally takes place via the company’s own process data network using the IEC 60870-5-104 transmission protocol. That combination of components has proved its capabilities with very few faults in everyday operation and has helped to achieve high levels of customer satisfaction at Westfalen Weser Netz.
As an additional challenge, around 300 energy generation plants with outputs over 1 MW are currently being fitted out with telecontrol systems in order to meet the requirements of the German Renewable Energy Act (Erneuerbare Energien Gesetz, EEG). The small SAE FW-5 telecontrol unit is being used for this purpose and allows control centre staff to reduce the feed-in rate of the energy generation plants. IT security occupies a specially important position in this project as the telecontrol systems are installed in the client’s stations. The use of additional firewalls and VPN encryption is this indispensable. The planning and configuration of the SAE telecontrol systems is carried out by employees of Westfalen Weser Netz. If unexpected problems or questions arise, help is available from the SAE service hotline.
As part of their ongoing training as “officially certified electrical engineers”, two employees of the municipal grid operator successfully completed their practical assignment using an SAE FW-5 telecontrol unit. The aim of the practical assignment was to secure a telecontrol system and its communication paths taking account of current legislation, regulations and standards. To that end the terminal devices (router and telecontrol unit) were hardware-protected, the communication channels secured by various measures, and end-to-end encryption implemented between remote terminal unit and process data network using IPSec. The end-to-end encryption in particular was new to Westfalen Weser Netz and is to be used more widely in future.