Pico and renewable energy
23/02/21
By Ben Martins
Renewable energy is a big thing these days. As world leaders aim for carbon neutrality to prevent climate change from running out of control, scientists and engineers worldwide are looking at ways to harness energy without burning fossil fuels. The most popular option is currently wind turbines. Wind farms, particularly here in the UK, are on the increase and there are more and more appearing along the coasts of countries across the globe. 20% of the energy used in the UK in 2019 was generated by wind and on a particular day in 2020, the UK saw wind power delivering 60% of the energy required for the country.
As the demand for cleaner and more sustainable energy increases, we can expect to see bigger and taller turbines. And all these turbines require maintenance. What is interesting is that these machines combine all of the main areas that the automotive team at Pico work in at the moment, with systems that involve high voltage, 3-phase motors, hydraulics and of course NVH. Some will rightly point out that most machinery like this has a monitoring system in place that can be remotely accessed to see the condition of a turbine. This is more commonly referred to as predictive maintenance, and it has been around for years in the industrial world. Some vehicle manufacturers are even attempting to integrate this into their on-board systems.
One particular problem in getting accurate and reliable real-time data. For something like a hydraulic ripple, a high sample rate is required which then leads to huge amounts of data often captured over days, weeks or maybe even months. Because storing large amounts of data and then analysing it isn't easy, these predictive monitoring systems tend to have fairly low sample rates. This leads to data that can be slightly unreliable in being able to pick up on developing faults and the system usually only raises the alarm when it's past the point of no return. An example of this is a generator bearing which gradually wears away till it overheats, fails or worse causes the rotor to contact and short the stator.
Supporting wind techs in this industry isn’t easy, due to the remote places the turbines are positioned. While we have learnt to adapt to a new way of providing support during the pandemic, it is very difficult to get an idea of how to apply the scope in the actual environment. To do this you have to be on site. The trouble is the components we're looking to measure are up to 200 m high in the air and are now more commonly found out at sea.
To be able to work on these turbines you have to have passed a minimum of the GWO (Global Wind Organization) basic safety training as well as a medical assessment. I have been very fortunate that Pico has let me carry out the GWO BST course which consisted of five modules. This will allow me to support wind techs directly, both on and off shore.
The course took 6 days to complete and consisted of Working at Height (including rescuing and evacuation), Manual Handling, Fire Awareness, Sea Survival and First Aid. After each module there is a written assessment but the important aspects are being observed during the practical tasks to ensure you passed the course. If you are missing one of these modules you will not be allowed to go on site and up into a turbine. Certification lasts 2 years, but you can avoid doing it all again by completing a refreshing course before the certification expires. I completed the course with MCL UK based purely on location as the other providers were all quite far away. They were also one of the few that provided the sea survival course which I have to admit was quite a surreal moment when you find yourself jumping into an old London reservoir in January! Joking aside though, sea survival does allow me to travel to the offshore wind farms. (Please ignore the hair length from lockdown 3!)
Having this certification means we can support an industry that is growing at an incredibly fast rate. With more and more wind turbines being planned for the future, making sure they can be fixed quickly and efficiently is imperative to ensure they carry on generating the electricity we are so hungry to consume.
In October 2020, the UK government announced its new plans to make the UK a world leader in clean wind energy. This includes the commitment to ensure that offshore wind will produce more than enough electricity to power every home in the country by 2030. The current offshore wind capacity meets 10 per cent of the UK’s electricity demand. (See www.gov.uk/ government/news/new-plans-to-make-uk-world-leader-in-green-energy.)
Naturally, along with this vast expansion in the number of wind turbines, there will be an increase in maintenance and diagnosis for when things go wrong. Making sure that the diagnosis is correct can potentially save hundreds and thousands of pounds, which is where scope diagnostics can help. Having portable equipment that can be powered purely by USB only brings flexibility to measuring a number of components rather than having lots of different tools all doing one job each. The ability to send and share files with the free software also means that anyone in the world can view a file.
Looking online, it isn’t hard to find a number of reports outlining the failures, with bearings being one of the highest. The bearings are under an immense amount of pressure and when you think about just the weight of the shaft connected to the blades and the forces involved when it is turning, you can see why they are prone to fail over time. The trouble is detecting an issue before it fails completely, which could lead to metal fragments dropping into the gearbox making the job more involved than it needs to be. If you could take a snapshot of the bearing and its condition based on vibration, then at each service you’ll have a detailed view of the bearing’s condition.
Looking at further data you can see that in addition to the bearings, the top three issues also include hydraulics and the generator (electrically and mechanically), with the gearbox coming in fourth. This would make sense as these are the components under the highest amount of stress during operation. Best of all, these components are all things we can accurately measure with a PicoScope and the relevant accessories we are already supplying.
I’m hoping that Pico can provide equally valuable support to the wind techs as they have done to the automotive industry. By combining knowledge gathered through the different supported industries, we are better positioned to continually support this growing industry. As my Dad once told me: “It’s all the same just different”. In this case, however, it does makes sense. Wind turbines feature many of the systems we already diagnose in other industries. I’m now looking forward to the call where we can directly support and help develop new techniques for working on these machines.
