Customer application 27 August 2020
Translator for the Central Nervous System

The Ulm/Neu-Ulm municipal utility (Stadtwerke Ulm/Neu-Ulm Netze GmbH) has converted its telecontrol technology to a sustainable network structure. A protocol converter from WAGO ensures smooth communication during this process.

For more than 160 years, the Ulm/Neu-Ulm municipal utility and its predecessors have been responsible for essential parts of the infrastructure in the two communities on the left and right banks of the Danube. It began with the gas supply; shortly after, drinking water was added; it then became responsible for the electrical supply at the end of the 19th century. In the meantime, the municipal utility also provides district heating, together with a partner. To guarantee a reliable supply that is also cost-efficient, the utility relies on a carefully balanced mixture of proven technology and new, innovative solutions.

It is now applying this strategy to the challenges of the energy transition. Due to the expansion into renewable energy, the power grid is consistently being supplied by smaller providers, generation has become more volatile, and control expenses have risen. The demands for security in critical infrastructure – including power, water, gas and heat – have also increased at the same time.

These provide excellent reasons for suppliers to revamp the structure of their telecontrol technology. In this context, the municipal utility has replaced the traditional star structure – in which the control center is at the center, and the substations are directly connected using RS-232 lines – with an IP-based network. This enables control of every point within the network through multiple paths. The risk of individual component failure is significantly reduced by the structural redundancy. “Our telecontrol system is the central nervous system for supplying Ulm and Neu-Ulm. Therefore, the conversion was an important step for us,” explains Sebastian Grenzner from his position at the network control center at Stadtwerke Ulm/Neu-Ulm Netze GmbH, the municipal utility company.

Secure communication in the network – here’s how WAGO supports you:

  • The WTG translates all data automatically from the IEC 101 standard into the IEC 104 protocol.

  • This allows all of the municipal utility’s 110 substations to be operated in the traditional way.

  • The restriction to a single ETHERNET modem type reduces the municipal utility’s costs by up to 30 percent.

“Our telecontrol system is the central nervous system for supplying Ulm and Neu-Ulm. The restructuring was a very important step.

Sebastian Grenzner of the network control center at Stadtwerke Ulm/Neu-Ulm Netze GmbH

Sustainable Communication for the Future

While communication in the star structure uses IEC protocol 60870-5-101, the network demands another language. The change to the IP-based technology forced the municipal utility to convert the entire data exchange between the control center and the substations – transformer stations, CHPs and gas transfer stations – to the IEC 104 protocol. The question was how to achieve this given the large number of interfaces and systems. According to Grenzner, there was no way to do this conventionally. “If we had had to convert everything manually, the expenses would have been enormous. We would have had to add each system by hand,” he explains.

Therefore, Grenzner began searching for a solution that would accomplish this task automatically. This led him to WAGO, whose telecontrol gateways (WTGs) already include an automated data concentrator for telecontrol protocols. In the first test, there were limitations on the serial communication. “WAGO was immediately willing to adapt their product to our needs and ensured open configurability for serial communication,” reports Grenzner. Like a translator, the compact WTG ensures that all data is automatically translated from the IEC 101 standard into the IEC 104 protocol, without the need for additional parameterization. The protocol converter is thus flexible enough to deal with the latitude that the IEC 101 standard offers manufacturers. There are small differences in the data outputs for each system – dialects of this language, so to speak – which WAGO’s WTG easily understands.

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In the control center, due to the increased use of renewables, electrical flows are becoming more complex, and controlling the network has become more expensive. Therefore, the Ulm/Neu-Ulm utility company invested in telecontrol technology.

If we had had to convert everything manually, the expenses would have been enormous.

Sebastian Grenzner of the network control center at Stadtwerke Ulm/Neu-Ulm Netze GmbH

Fast Implementation, Easy Operation

“Using the WAGO solution saved us time and money,” says Grenzner in summary. In addition, the protocol converter ensures that the municipal utility can continue to operate all 110 substations currently linked to the network in the established way. Many of the systems have been running for twenty years or more; these are reliable, proven technologies on which the supplier relies. Some of them have been in operation long enough that their documentation is only available in handwritten form. In these cases, a manual conversion to the IEC 104 protocol would have been impossible or required an enormous expenditure of effort. By incorporating the WAGO solution, the municipal utility avoided the need to invest in new network-capable systems when the existing technology already functions perfectly.

The automated conversion also lowers costs, increases efficiency and improves security at other points within the network. According to Grenzner, the municipal utility has been able to limit its modems to a single ETHERNET type. This alone leads to 30 % savings in this area. The utility also profits during maintenance and repair work. “Our colleagues only have to be familiar with one modem type.” In addition, the protocol converter allows the control technology to switch a limited number of inputs and outputs in the substations – to pass fault messages through or acknowledge messages – without requiring updates to the substation control technologies. “It functions perfectly,” says Grenzner in praise of the technology. “We can freely set up the inputs and outputs at little to no expense.”

The municipal utility required a mere three weeks to bring all 35 protocol converters on line. “There were no problems. We expected to have to spend more time on this,” explains Grenzner. The setup was carried out using Web-Based Management. “We had all the information we needed right at our fingertips thanks to the Web interface. In addition, we could see the protocol in detail, down to the hexadecimal level.”

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Newly connected: The WAGO Telecontrol Gateway ensures that all components connected to the telecontrol network in Ulm and Neu-Ulm can continue to operate in their proven manner.

Redundancy Creates Security

With the new telecontrol structure, the municipal utility of Ulm/Neu-Ulm has created a sustainable, economical and efficient control system that satisfies the highest demands on quality and security. In addition, the utility was able to use the ring network to establish a second, remote telecontrol station to function as a backup with the same functions in the case of emergencies. This redundancy provides the utility with flexibility in for spatial expansions, since the central control center will have to be renovated in the foreseeable future. As a central component of the new network structure, the WAGO protocol converter has made an important contribution to the security of the power supply to these twin cities on the Danube.

Text: Kay Miller | WAGO

Photo: Ralph Diermann, Kay Miller | WAGO