Keeping an eye on how a plant is operating is vital for all Voith Hydro customers.
However, keeping an ear on it is even more important, as mechanical problems can often be heard before they can be seen. The problem is that sending technicians around a plant to listen for anything unusual is time-consuming, expensive and intermittent – especially if the plant is in a very remote location.
Rudolf Münch at Voith uses the comparison of a mechanic assessing a car to describe the approach he and his colleagues have taken to design a solution. “About 50% of what a mechanic finds out about your car comes from listening for potential problems. HyGuard applies this principle to hydropower plants.”
HyGuard technology works through a series of sensors installed at strategic locations around a remote, unmanned power plant. The system records sounds, which operators – perhaps based hundreds of kilometres away – can assess for any abnormal noises. And if, for example, one of the sensors sets off an alarm, the operator can make a quick assessment, and immediately send the recording to an expert for analysis anywhere in the world.
So far, so clever – but there is more. “The second part,” says Münch, “is that if the same problem occurs repeatedly, the system will recognise the sound from previous failures.”
In short, the system has ‘self-learning’ capabilities. “Sounds have different properties, and in the case of the rotating machinery in a hydropower plant, a lot of information is hidden in lots of different frequencies,” explains Münch. “The application checks for general patterns in the frequencies, such as those that work together or don’t.
These patterns are learnt, along with new patterns. Subsequently, the application compares the patterns to discover what is abnormal.”
The first series of tests, consisting of microphones recording sounds for several days at a time, have already been carried out successfully at a hydropower plant in Germany. The next stage is to install the technology permanently at a pilot plant later in 2017, also in Germany.
Once the experts have sufficient experience with the pilot, the technology can be offered worldwide including in remote plants in Africa as part of the company’s new service concept. “With long distances and variable transport infrastructure, remote monitoring there makes perfect sense,” concludes Münch.