Unlike equipment and machinery that are configured and operated on the ground, typically like in a workshop or factory scenario, installations either at higher altitudes or on some special decks and platforms will have a different set of rules for both their operations and maintenance.


Wind energy for example is one such good case; with such massive scale of its installations going around in India and the world, the challenges of putting the sub-systems together in a time bound manner and make them operational at heights over 100meters from the ground is a challenge of sorts; the varying installation site conditions and other geographic variables all add to this uphill task.


Then comes in the continued operational part of the activity; a typical wind energy tower has 3 to 4 major components namely the turbine blades, the gear train, generator and the electrical panels, all of them installed at the topmost part of the tower. The turbine blades operate anywhere between 10 to 20 RPM and through the planetary gear sets, the speed is increased to around 1500 RPM at the generator input.


A number of good quality scheduled maintenance practices are required to keep the tower operating at its optimum. The turbine blades need to be at their best of balancing quality given the fact that their spans are over 40 meters; even small number of residues, accumulations and erosions on the blades induces significant vibrations harming the entire connected systems.


Bearing, gears and other rotating equipment health are to be monitored and assessed on a continued basis; land-based wind towers typically have their peak cycle of power generation for about 6 to 8 months in a year and the uptime of all the rotating equipment shall be at their optimal conditions to generate maximum power. On the other hand, offshore based towers operate through the year and the maintenance strategies needs to be even better planned.


The tower itself is subjected to high wind loads and changing wind indexes, the entire tower will be oscillating in asymmetric axis based on the incidence of wind loads; resonance & fatigue life of the tower is of a great concern since the operational speeds of the turbine blades fall close to the natural frequency of the tower mast, the problem gets compounded based on the soil strata and foundation conditions.


Traditional methods of conducting vibration-based condition monitoring such as visit of technicians to site, usage of portable equipment etc are actuely challenged by the remote locations of the wind energy farms, time required to access the nacelle area, safety and work at height considerations etc. The time required to just gather vibration data from the rotating equipment will simply outweigh the economics of unit per hour generation equations and thus becomes nearly an obsolete approach.


IoT based sensors and instrumentation are fast replacing the entire process of the condition monitoring in the wind energy sector; they are versatile, intelligent and can include many data sets that makes the health monitoring management more holistic and complete.


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The IoT systems of the present day include temperature, vibrations, electrical parameters, wind data and even the tower oscillation profile, all in real time. The systems are near autonomous with a robust data and dashboard organisation. The health alarms are made available on mobile phones making them a boon to the O&M teams.


The data being monitored over thousands of such towers are being used for mining & analytics paving way for the next generation AI based vibration and other condition monitoring tools from very remote offshore wind towers. The eco-space of IoT based sensors systems are completely changing the economics of feasibility of maintenance practices at gross levels.


NV Dynamics worked at the discrete levels of vibration-based condition monitoring for few years but realised the importance of using IoT systems as the way forward; other than using customised IoT for various applications, we also work with two of IoT development teams evaluating various possibilities that include 5G network and AI capabilities.