In total, Alliander has installed 6 DDW-221 units and 280 DDW-100 units to upgrade its gas distribution system and convert it into a modern communication system monitored and controlled by SCADA.
Alliander (formerly Nuon) is one of the largest energy providers in the Netherlands, serving 2.5 million customers in the Netherlands and Belgium. The company generates and distributes electricity (20 TWh per year, both green and grey) and gas to a significant portion of the Dutch residential and industrial market. One of Alliander's divisions is Liandon (formerly Nuon Tecno). This engineering and projects division was contracted to provide a telemetry system for the gas network in Amsterdam.
The city of Amsterdam has a large number of gas substations, enabling Alliander to regulate the gas distribution network in the Dutch capital. However, there was a requirement not only to regulate but also to monitor consumption in real time, as well as alarms and flow measurements. With this information, Alliander can provide better services to its customers and reduce costs. For the remote telemetry unit, Alliander chose a new RTU, the D05 from Datawatt Telecontrol Systems, which uses the IEC 60870-5-104 communication protocol based on Ethernet (Figure 3). Using fiber optic cabling for Ethernet communications would have been the logical choice, as many of the Ethernet links would exceed the maximum range of 100 m for UTP cable. However, fiber would have been too expensive and nearly impossible to install in the short term and in a densely populated city.
The solution was simple: leverage the existing copper cabling in Alliander's own telecommunications and signaling network. "After some successful tests with the Westermo DDW-100 and our previous experience using the Westermo modem family, Alliander opted for Westermo's Ethernet Extenders, distributed in the Netherlands by MODELEC," said Rens Dekker, chief engineer at Liandon.
The main specifications were galvanic isolation, an extended temperature range, and DSL line performance. Testing was conducted up to a distance of 17 km. Alliander is using a DDW-221 ring to form a central, redundant ring (Figure 4). From this central ring, 140 point-to-point communication lines are used to connect remote locations (gas substations). Each point-to-point link consists of two DDW-100 units to extend the Ethernet link up to a maximum of 12 km. In total, Alliander has installed 6 DDW-221 units and 280 DDW-100 units to transform its gas distribution system into a modern communication system monitored and controlled by SCADA.
