How Atten2 prolongs the useful life of wind farms

One of the most widespread concerns in the wind energy sector is how to prevent the wear of machinery in wind farm turbines. Traditionally 20 years was the estimated performance of a fleet of wind turbines, whereas now the useful life is expected to extend by another 10 years, to 30.

The longevity of these installations for obtaining energy has meant that in the current market large, modern turbines coexist with others that are small or medium sized , consisting of turbines of between 1 and 3 megas. In the case of these older wind farms, the necessity of prolonging their useful life means making some modifications to their design and taking steps to minimise the risks of breakdown.

In this regard, real time monitoring of the machine through an analysis of the condition of the lubricating oil by the Atten2 optical sensors makes it possible to diagnose the state of the critical machinery and to anticipate failures.

ATTEN2 Technology to prevent wear in wind turbine machinery

In industrial processes, the seriousness of the failures that can occur in machinery is measured in terms of risk, a concept for weighting breakdowns that combines the probability or frequency with which they may arise and their impact, that is to say, the financial scope and the time required for repair.

In wind turbine there are a number of different critical elements: the electrical part, the mechanical part and the control part. The electrical part is where failures most frequently occur but they can be fixed rapidly, whereas in the control the probability of breakdowns is significantly lower. It is in the mechanical part that the greatest risk is to be found since, although the failures are less frequent, the repair time and financial scope are considerably greater.

ATTEN2 optical sensors to prolong the useful life of the multipliers

Of all the mechanical elements of a wind turbine, the most critical is the multiplier, a mechanism that is the focus of many maintenance efforts with the goal of presenting potential high-risk failures.

In this regard, the Atten2 optical sensors are able to anticipate failure through real time monitoring of the condition of the lubricant. The Atten2 technology detects, quantifies and classifies the particles present in the flow, which allows a diagnosis of the state of the machine and the taking of corrective measures to prevent a breakdown or to minimise its impact.

Increasing the visibility of possible failures

The Atten2 solutions lend visibility to a percentage of possible failures of the multipliers that are undetectable through preventive maintenance.

Of all the possible breakdowns that this machinery might suffer during its useful life, it is estimated that a high percentage, up to 35%, are not observable in the routine checks. Predictive maintenance by means of Atten2 condition monitoring of gives a 25% increase in the visibility of these ‘invisible problems’, so that their capacity for diagnosis covers 85% of the possible incidents, which means a notable decrease in the risk of suffering unexpected breakdowns.

Among the anomalies that the Atten2 sensors are able to detect rather than other monitoring solutions on the market is the unequivocal detection of the presence of air inside the lubrication system. This problem, which could be due to a failure in the assembly of the lubrication system, leads to oxidation in the lubricant, which can lead to mechanical failures as a consequence of wear by rubbing. The principal added value of the Atten2 systems is that they are able to distinguish between the presence of particles and bubbles of air in the lubrication fluid.

A step forward for analytical ferrography

The Atten2 optical sensors can identify the machine’s tendency to wear and the form in which this wear is coming about. The system not only measures the number of particles that are circulating through the oil but, based on their shape, it can identify the type of failure that their presence is causing and make a precise diagnosis of the state of the machine.

A mechanical element can fail for different causes, for example mechanical fatigue, cutting forces, rubbing forces or corrosion problems. All these kinds of wear leave their own particular mark, both in the component and in the particles that become detached, shapes that are identified in real time with monitoring by Atten2 optical sensors.

Traditionally studies on the state of the oil have been done in laboratories using a technique called analytical ferrography. This is a manual process in which a sample is placed under a microscope and a specialist, with a shape guide, determines the categories to which each particle corresponds. These tests not only lead to inaccuracy but are very costly and require an important investment of time.

Accurate diagnoses linked to operating condition

Thanks to the online system of the Atten2 sensors, the identification is done in real time, which requires a smaller investment in time and resources, as well as giving greater accuracy to the precision to the diagnosis.

Moreover, the Atten2 technology, unlike laboratory analysis, makes it possible to link the working conditions of the multiplier with the state of the lubricating oil, a decisive aspect for making the diagnosis since the wear behaviour is closely connected with the operating conditions of the machine.

The patterns of normality that are recorded in the Atten2 on-line system make it possible to tell when the wear of the oil is heightened by anomalies in the machine or if this wear is in line with the load conditions under which it is operating.

Data for taking proactive measures

The real time data that are obtained through the Atten2 optical sensors make it possible to anticipate a failure in the critical machinery, but they also provide useful information for taking proactive maintenance measures that positively affect the useful life of the machine.

In a wind park where the Atten2 sensor system is installed, the monitoring of the state of the oil revealed a high presence of metal particles in the oil that returned to the multiplier, particles that were generating a high level of abrasion wear. These data made it possible to determine that the machinery needed greater cleaning of the returning oil to prevent this accelerated wear of components. With a minimal investment, the installation of an additional off-line filter, the percentage of wear of the machinery was reduced by 20%, with which the customer was able to prolong exponentially the useful life of the machine and minimise the possibility of recording failures in the future.