IEC 60870-5-101, IEC 60870-5-104, Modbus
As an operator of electricity and gas lines in around 1000 municipalities in Schleswig-Holstein and north Lower Saxony, Schleswig-Holstein Netz AG is responsible for the safe and reliable operation of its energy networks. In total, 1200 employees operate around 51,000 km of high, medium and low voltage networks as well as 15,000 km gas and 7500 km communication networks in Schleswig-Holstein and north Lower Saxony.
Within this gas network, Schleswig-Holstein Netz AG operates – amongst other infrastructure – around 250 gas stations, in which gas is imported from the 80 bar and 16 bar transport networks of the upstream suppliers. These stations were monitored via 2 units in the past: one unit serving as station monitoring for the measurement of e.g. gas volume, temperature and pressure and one telecontrol unit for transmitting the measured data to the control centre.
A new goal was set when optimising the operational processes in line with IT security: Renewing the technical equipment of the stations was meant to enable easier and faster system conversions. Schleswig-Holstein Netz AG regarded reducing the hardware components in the stations as a necessary step towards achieving this goal: The telecontrol and monitoring functions were to be implemented by just one unit in future.
The distribution system operator found a practical solution in a uniform combination of hardware and software for all 250 gas transfer stations, enabling simple automation functions even without an external PLC: The tasks of monitoring and control are undertaken by the versatile telecontrol unit net-line FW-50 from SAE IT-systems. In combination with the software tool codeIT, value conversions, logic links, regulation systems or safety locks and releases can be implemented from the control centre precisely in line with requirements. To enable manual inputs of control parameters on site as well, a terminal display made by Sütron was installed in the door of the switchgear cabinet. Thanks to a 3-day software training course at SAE IT-systems in Cologne, autonomous handling of this solution is no problem for the Schleswig-Holstein company.
The further basic equipment of the switchgear cabinets installed in the systems typically includes the intrinsically safe explosion protection provided by R.Stahl Schaltgeräte GmbH, which is absolutely essential at transitions of gas into the electrical area, an uninterruptible power supply, power supply units, fuses and surge protection. Various protocols are used during communication between the components themselves: DSfG, Profibus, Modbus as well as 3964R/RK512. The connection to the control centre is realised via IEC 60870-5-104 and -101. Redundant connections were also created for especially important gas stations. External stations were also connected to the control centre of Schleswig-Holstein Netz AG with this switchboard concept.
The north German distribution system operator has opted for a uniform telecontrol unit from a single manufacturer for all cabinets and systems for good reason: simplified troubleshooting. “We’re poised for the future with this system” states Timo Marcussen from Schleswig-Holstein Netz AG. The company’s employees and their outstanding technical qualifications carried out the 250 system conversions themselves, while maintaining operation at the same time – a demanding yet efficient plan: Instead of the planned run time of 5 years, the complex project was successfully realised within just 4 years. During the course of the project, the Schleswig-Holstein company followed the project principle of agile project management: Problems arising during the course of the project such as coupling via various bus technologies, difficulties in the odorisation or in the heating control were gradually solved.
“In such a complex project, you can’t always foresee all eventualities to incorporate them in the planning.
Together with SAE, we’ve therefore developed short-term solutions for upcoming problems.”
Timo Marcussen, Schleswig-Holstein Netz AG