25 May 2022

LoRa devices help Swiss utilities towards digital transformation


Distribution System Operators (DSOs) are being helped to meet information needs by Elvexys, a European company specialising in grid data management. Combining Elvexys’ knowledge in the acquisition, processing and conversion of industrial communication protocols with IIoT technologies, it proposes scalable data collection solutions to both utilities and industry. Using Semtech’s LoRa devices for industrial wireless networks allows an easy connection to remotely sited devices such as substations and gas, electricity and water meters. Smart Futures reports.

Elvexys was keen to use an Internet of Things (IoT) solution, as it would allow the monitoring of existing installations without being intrusive or causing interruptions to the supply.Utilities are increasingly looking to get more information on their distribution networks. Faced with the challenges of cutting maintenance costs, avoiding unnecessary servicing and maintaining a high-quality supply to end users, they want systems that can give rapid updates on the status of equipment such as substations.

One company helped by Elvexys is electric utilities provider Oiken, which serves 90,000 customers in the Valais region, the third largest canton in Switzerland. The company wanted better information on the status of its Intelligent Electronic Devices or IEDs, which control the conversion from 16KV to 400V in its high voltage/medium voltage power substations. Each power substation has two IEDs making a total of 2400 IEDs for the 1200 power substations of Oiken to monitor.

In the past, Oiken’s distribution network relied on aerial cables, for both low and medium voltages. These networks are now mainly underground. This gives the advantage of better reliability but also makes it more difficult to locate failures.

With the aerial distribution system, failures are easily visible, though delays can ensue due to the need to send engineers to the probable location.

Elvexys says it has a wealth of experience of the challenges facing DSOs. One challenge is that they are often missing a lot of data. High voltage substations have IEDs, but DSOs often do not have similar facilities for their medium voltage equipment. Because of this, DSOs will often rely on their experience of how the grid has behaved in the past and not on hard, up to the minute data.

Lack of data becomes a particular problem when there are faults on the line. In this case, DSOs will need to estimate where the fault lies and to send people out in a vehicle to try and locate it more accurately. As well as monetary losses and disruption for end users, this can lead to penalty charges for the DSO for failing to supply customers.

From the transformer to the control room

Elvexys offers an end-to-end data collection solution based on a LoRaWAN network. Other solution providers may propose PLC devices (Programmable Logic Controller) that are complex to use and provide too much information and the data is also never collected right up to the SCADA systems.

This end-to-end solution extends all the way from the Rogowski coil at the measuring node, through gateways using LoRa that transmit the data and on to the client’s SCADA system. Parameters are measured on all three phases and include currents in low, medium and high voltage transformers, as well as temperature and humidity.

The data can be processed and amalgamated to suit the client’s needs, with calculations performed on the raw data and the results presented in the way the DSO wants.

There is also a fourth channel to measure homopolar currents. With this, all three phases are measured together, which means if there is an imbalance on the line or a current loss through a branch on a single phase, the homopolar channel will see it and alert the SCADA system via a gateway leveraging LoRa.

Elvexys also provides the LoRaWAN network to the DSO, as well as any necessary protocol conversions, including IEC 61850, Mbus and EtherCAT. Having their own private network means the DSO can secure it against blackouts and other disruptions, either through power over Ethernet or through using batteries.

LoRa is the de facto wireless platform for IoT. Compared to connectivity technologies such as cellular 4G and optical fiber, LoRa offers rapid and easy deployment over a wide area, reducing both capital and operational costs. It is particularly suitable for DSOs, who need to monitor equipment that could be in remote or difficult to reach locations.

Semtech’s LoRa chipsets in the gateway enable real-time communication of data and analytics that can be used to enhance efficiency and productivity. LoRa devices enable smart IoT applications that solve some of the biggest global challenges, including energy management, natural resource reduction, pollution control, and infrastructure efficiency.

Lower cost error detection

By partnering with Elvexys, Oiken has a capable, IoT based solution using short circuit detectors installed in its power substation. This gives the company the exact locations of the short circuit failures in the grid.

The solution saves Oiken a lot of time in detecting failures. It also saves money by providing better protection both to its own assets and those of its customers, by avoiding cascades when reconnecting power after a short circuit.

Xavier Emmery is responsible for the deployment of the sensors utilising LoRa and their integration into the supervision centre, which he also manages.

“It’s clear that if we had opted for a solution based on control commands, it would have required much more time, about 20 years to deploy, and would have cost us 10 times more,” says Emmery.

“LoRa gave us a better solution by making it simple to collect information via a Rogowski coil and display it directly to our supervision platform, making it easy to locate failures.”

LoRaWAN community

Working with Semtech means that Elvexys is at the heart of the LoRaWAN community, the open standards movement of which LoRa forms the basis.

Christian Leggett, project engineer at Elvexys, commented: “Semtech provided us with lots of insights about the standards. Being a relatively young standard, LoRa is being rapidly improved, so working with Semtech, which sets many of the aspects of the standard, keeps us informed about new developments we could make use of to improve our solution.”

One project Elvexys intends to pursue is the ability to push data to the nodes as well as receiving it. This would allow changing of setpoints, sending commands to the nodes and over the air updates to firmware. They are also looking at using homopolar detection to detect current losses at lower voltages, securing energy supplies all the way to the buildings that its client DSOs serve.

Elvexys was looking for a connectivity solution that would allow their DSOs customers to solve their network monitoring challenges. It had to be based on standard communications solutions, offering long range and the ability to connect to power and current sensors without causing disruption to clients’ facilities.

As a major driver of the LoRaWAN standard, Semtech is well placed to help Elvexys develop its offerings as the standard develops. For DSOs like Oiken, the solutions offered by Elvexys means they get a much better view of their distribution system’s performance, allowing them to better meet their obligations and improve their service to their customers.

Company info: Semtech EMEA Limited