Moore’s Law – the observation that computing power doubles approximately every two years – can be applied in amended form to a whole range of products and technologies. The cars we drove 15 years ago look positively old-fashioned today, while a desktop PC that was the new century’s latest development (remember Windows 2000?) is now
Making a great idea even better
Sometimes the best ideas need creative thinking and cleverly applied technology to make them even more efficient and effective. One excellent example is the way in which Leitner Technologies used Omron technology to maximise the benefits of their unique Leitwind wind turbines, the first of which was introduced in 2003.
Leitwind turbines use a patent direct-drive mechanism operating on a permanent-induction synchronous generator. This gearless/brushless system is a highly efficient system of power generation, because it substantially reduces the mechanical and electrical losses associated with indirect drives. There are also fewer moving parts, so maintenance is reduced, service costs are lower and reliability is improved.
Mind the gap…All of these benefits depend on maintaining an accurate gap – the phase register – between rotating and static parts of the generator. Even small variations of less than 0.1mm from the optimum can cause a significant loss of generating capacity. Therefore, measurement and control of the gap is one of the key operations performed by Leitwind technicians during installation and maintenance of the turbines. Until fairly recently, the engineers used tools such as feeler gauges to carry out these checks. This is not a particularly accurate method and, because tests are sometimes conducted on the moving generator, they are potentially dangerous.
This is where the creative thinking came in. Leitner worked with Omron engineers to develop a measurement system based on a laser sensor integrated with three servo-motors. The sensor provides accurate profiling and measurement of the generator sections to detect any variations from the optimum gap – and the servo-motors make the necessary adjustments to correct any variations. It’s a non-contact system that provides immediate and highly accurate feedback on the status of the generator, eliminating the need for a monthly inspection.
Faster, more reliable, safer
The system’s resolution and the fact that it delivers continuous measurements mean that measurement is now faster and more reliable. It’s also totally safe – even when the turbine is rotating. And there are longer-term benefits as well because the system profiles the complete circumference of the rotating element, checking for any misalignments, and provides data-logging through a PC network for analysis of performance over time. This will help identify any continuing issues, as well as drastically reducing the time spent on maintenance.
In a sense, what is most important about these benefits is that they were achieved by combining the knowledge and experience of engineers from two different disciplines. Leitwind engineers understand the mechanics of direct-drive generators; Omron designers know about combining laser sensors and servo-motors. The result is a system that made a great idea even better.