Ethernet switches take on substation duties

The ES42 range of industrial Ethernet switches have been deployed to improve substation communications on the Italian national grid.

After a major electricity blackout across Italy in 2003, the Italian National Agency for Country Power Management (GRTN) suggested using more sophisticated and automatic systems to manage high voltage electric charges.

One of the results was the upgrade of 15 substations, with industrial instrumentation networked over Ethernet using hardened Ethernet switches from GarrettCom.

It was in 1962 when, after a long parliamentary debate the Italian Chamber of Deputies adopted legislation to nationalise the country's electricity system.

The decision was taken with the objective of making optimal use of resources, catering to increasing demand for electricity, and ensuring equal conditions for all.

On 6th December of that year this legislation became law and Enel (the Ente Nazionale per l'Energia Elettrica - National Electricity Board) came into being.

After decades of monopoly the nationalised energy market was opened up, but Enel remains one of the leading energy producers and has seen the electricity industry play a key role in Italy's economic and social growth.

Over the last few years there has been a dramatic increase in electric utility automation, and in substation automation particularly.

Consequently IEC61850, a common communications architecture, was conceived to define the communication between devices in the substation and the related system requirements.

The goal was to enforce interoperability between a variety of intelligent electronic devices (IEDs).

In parallel, the latest developments have seen power utilities increasingly turning to industrial Ethernet as a networking backbone for the automation of substations, because of its high reliability and feature rich specifications.

These include built-in fibre for high EMI noise immunity, 48 and 110V DC power operation, and extended temperature operating capabilities.

These specifications allow Ethernet LANs to be designed into substations with control and instrumentation equipment to maintain high availability of electric power to the public However, the Ethernet components used must conform to the same criteria as protection IEDs if they are located in the same place, and must be able to operate at the temperature extremes of -40C to +85C.

Enel is not only one of the largest producers and suppliers of electricity in Italy; it is also tasked with co-ordinating the use of the transmission grid with the generation facilities to ensure, at all times, the continuity and security of the electricity supply.

Thus, as part of its plan to increase the automation of substations, Enel was keen to introduce monitoring and recording of faults and events on the electrical powerlines.

The project to upgrade 15 key substations as part of this strategy was undertaken in partnership with Italian integrator Fort Fibre Ottiche.

The project requires hardened Ethernet switches which are IEC61850 compliant and offer high reliability.

It also requires Ethernet media configuration flexibility that includes mixed 100Mbit/s fibre and 10/100 copper.

Another major requirement for the power utility is that the Ethernet devices need to be able to operate at 12/110V DC.

Fort Fibre Ottiche chose GarrettCom's versatile ES42 range of compact, low cost, 6-port industrial Ethernet switches for its customer Enel.

The ES42 boasts high reliability as shown by the IEC61850 and IEEE1613 standards compliance, and the products' rigorous testing fulfils the criteria deemed necessary by the power utilities industry to support mission-critical applications.

This means demonstrating high reliability, electromagnetic radiation immunity, and sustained operation under temperature stress among other tough conditions.

The ES42 range of industrial Ethernet switches have been designed to provide seamless connectivity from the most remote device right up to the IT department.

The ES42 range is designed for use in challenging industrial environments - increasingly where small groups of PLCs or other industrial devices need to be connected upstream over a fibre cable, or where multiple devices need to be aggregated and connected over copper cable.

Incorporating the latest networking technology and innovative product packaging features to meet the needs of utility substation applications as well as demanding factory floor applications, the ES42 switches include link-loss-learn (LLL) functionality which enables them to be used in self-healing and redundant LAN structures.

The LLL feature allows ES42 switches to sense link loss or standard STP/RSTP reconfiguration signals on designated ports.

This, in turn, simplifies and speeds up recovery by changing the flow path of the LAN packets and passing the reconfiguration signal down the link to other products in the redundant network structure.

Edge switches, combined with managed switches running STP or RSTP or S-Ring, can often provide high availability redundant LANs at a lower total cost than was previously possible.

The compact design provides six Ethernet ports, with base models having a choice of two 100Mb fibre and four 10/100 copper ports, one fibre and five copper ports, or six copper ports.

The fibre port choices cover all multimode and single-mode fibre connector types.

Fort Fibre Ottiche selected combinations of the ES42 hardened Ethernet switches including the six copper port model and the four copper, two 100Mbit/s ST fibre model to create a network across the transmissions grid of 15 substations.

This allows Enel to monitor and measure the faults and events on the electrical power lines, with analysis capability.

Measurements are taken using industrial instrumentation equipment - a digital fault recorder (DFR) and a sequence of events recorder - supplied by Italian manufacturer Hi-Tec.

The DFR is essentially an Ethernet enabled data logger system dedicated to measuring faults and events in power generation plants and high voltage substations.

Measurement of data at each substation is taken by a computerised control unit.

Each substation has a star topology with two arms and a subarm.

Luigi Campilii, Product Manager at Fort Fibre Ottiche, comments: "GarrettCom's broad line of Ethernet products is perfect for anyone supplying networking solutions into power utility environments".

"Not only do they provide IEC61850 compliance, they also offer industrial class construction for more extreme environments".

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