Wind farm turning big data into smart data

More than 800 sensors strategically positioned on the wind turbines at Australia’s newest wind farm will play a key role in ongoing research by Siemens to optimise performance and minimise the need for potentially costly maintenance.

Every rotation of the ninety 3 MW turbines at Snowtown II wind farm is continually monitored off-site to develop key target values that can evaluate potential errors and correct them remotely. It is another example of the state-of-the-art technology incorporated into Australia’s latest renewable resource power plant and demonstrates the engineering expertise available in Australia.

“This is a wonderful example of the benefits of continually developing the engineering talent we have here in Australia so they can be part of the exciting work that is going on at a global level,” said Engineers Australia Chief Executive Officer Stephen Durkin.

“It’s another example of how Siemens and Engineers Australia are working together to advance the engineering profession for the benefit of the communities we serve,” Durkin said.

Siemens Ltd CEO Jeff Connolly said it also represented a graphic illustration of the transformation of big data into smart data and the move towards a digitalised economy in preparation for the fourth industrial revolution.

“The information from Snowtown II is fed to our monitoring centre in Denmark, which collates similar data from Siemens’ wind farms around the globe. Last year the database contained 97 terabytes of data. That will grow to 268 TB by 2015.

“Ten years ago it would have taken 1000 years to produce five billion gigabytes of data. Today, we can produce that amount in 10 minutes and the data captured from Snowtown II is part of that growth,” Connolly said.

“The challenge is turning that information into meaningful information to enhance productivity. We call that smart data, and the Siemens wind power service centre is an excellent example of digitalisation for efficiency.

“This is a good illustration of where digitalisation technology is being used to help efficiently electrify the world. It’s an example of Industry 4.0, where software and data play a much bigger role,” Connolly said.

The huge amount of data collected from Siemens wind farms is used to remotely monitor tiny variations and identify potential defects long before any service work is required.

“In some cases, our engineers can detect defective main shaft bearings up to a whole year before they have to be replaced. This means our technicians can anticipate damage before it actually makes itself felt,” Connolly said.

Digitalisation technology - how it works

Data from the Snowtown II site flows continually to the diagnostic centre of Siemens Wind Power Services in Brande, in western Denmark. The facility collects and evaluates all the operating data from more than 7500 Siemens wind turbines all over the world.

This flood of data is collected by the SCADA and Turbine Condition Monitoring (TCM) systems from Siemens. While the SCADA system collects the turbines’ electronic and mechanical data as well as information about weather and power grids, TCM is a vibration recognition system.

Each wind turbine nacelle contains up to nine sensors that measure the vibrations of the turbines’ key components: the transmission case, the generator and the main shaft bearing at the rotor blades. Each turbine at Snowtown II is equipped with TCM, which monitors them 24 hours a day, 365 days a year.

After the vibration data is collected, it is transmitted to a reference database in Brande. The centre automatically processes this data to create sample values for the normal operation of the various types of wind turbines and continuously compares these target values with the current operating data of active turbines.

The vibration sensors can detect even tiny deviations that indicate a potential defect. This enables the system to discover a damaged gear wheel, for example, long before the transmission breaks down. When needed, Siemens engineers can remotely switch off the affected wind turbine and send someone for repair work.

The centre measures more than 2500 anomalies every week. The 100 analysts at the facility investigate these error messages and transmit more than 100 early warnings to the service technicians every week. If a case is serious, the technicians go directly to the affected turbine to take care of the matter after the centre has provided them all of the information about the turbine and its operating history.

The flow of extremely detailed data is the key to the system’s success because it enables diagnostics experts in Brande to precisely determine what kind of defect they are dealing with and whether or not a service team needs to be sent out to the affected turbine.

For example, if individual turbine components exceed or drop below temperature tolerance ranges, the wind turbine in question automatically shuts down. However, if the off-site technicians come to the conclusion that the anomaly is not serious, they can remotely restart the wind turbine as soon as the temperatures have returned to their normal values.

Performance data from the remote monitoring system is impressive. Siemens’ engineers can remotely solve issues affecting 80% of the stopped turbines within 10 minutes.

A further 5% of the problems take somewhat longer to solve, but do not require technicians to be sent to the defective turbines. In only 15% of the cases do service technicians actually have to go out and work on the affected wind turbines.

Siemens Wind Power Services has long been an advocate of using the advantages of smart data. In 1998, Siemens became one of the first companies in the world to install sensors in its wind turbines as standard procedure.

Snowtown II background information

Officially opened by South Australian Premier Jay Weatherill on 2 November, Snowtown II will produce 989 GWh annually - enough to provide clean, emission-free power for 180,000 homes.

Construction on the $439 million Snowtown II project began in August 2012 and involved about 500,000 man-hours. Siemens provided a full turnkey project solution for the wind farm including the associated 275 kV high-voltage substation.

The 90 turbines at Snowtown II represent the largest installation of Siemens’ Direct Drive technology commissioned to date. The Direct Drive technology uses half the moving parts of a conventional geared turbine, resulting in reduced complexity and increased reliability.

Each turbine is driven by three blades, ranging in length from 49 to 53 m. They are of a single piece construction, made from fibreglass-reinforced epoxy resin. As a result, all glue joints - the potential weak points that could expose the structure to cracking, water ingress, ice formation and lightning - are eliminated.

Weighing in at 10 tonnes, each turbine rotor spins at up to 16 rpm, resulting in a tip speed of over 300 km/h, similar to the top speed of a Formula 1 race car or a high-speed train. In total, the swept area would cover a site more than eight times the size of the Adelaide Zoo.

Transporting the blades was one of many logistical issue Siemens’ engineers had to overcome. Laid end to end, the 270 blades would result in a road train more than 14 km long. Over the course of several months, each of the 950 pieces constructed off-site were transported, with about 500 requiring a police escort. The size of the project site required construction of 50 km of new roads, providing an added benefit with increased access for Country Fire Service volunteers.

Siemens extensively utilised South Australian businesses to help deliver the project. Local supply and services contracts in excess of $75 million were awarded, including fabrication of 20 towers by Whyalla engineering firm E&A Contractors and civil and electrical installation works by a consortium of Civil and Technical Constructions and Consolidated Power Projects, both of Adelaide.