## 1 Introduction  
Demographic and industrial growth in many countries is driving an increasing demand for energy supply. Under this pressure, intense competition for resources has led some nations to adopt solutions that are harmful to the climate and, more critically, to human well-being [1]. In 2023, global statistics showed that 82% of energy production came from fossil fuels, compared to only 13% from renewables and 5% from nuclear power. Among the clean and sustainable alternatives are wind, ocean currents, and solar power [2]. Wind energy, in particular, stands out as a viable solution for many countries, with two main configurations: onshore and offshore wind turbines [3]. In 2023, global installed capacity reached 906 GW, with 68% from onshore installations and 32% from offshore [4]. This growth is driven by high efficiency, substantial power output, and a competitive cost ranging between USD 26 and 54/MWh [5]. That same year, wind turbines reached power outputs of up to 18 MW for offshore models and 10 MW for onshore ones. In the near future, the market is projected to reach USD 102.4 billion, supported by the deployment of 25 MW offshore turbines and 15 MW onshore turbines, equipped with rotor diameters of 350 and 270 m, respectively [4]. However, like any system or machine, wind turbines cannot operate indefinitely without experiencing faults. These machines rely on complex transmission systems and function under harsh environmental and operational conditions. High humidity,for instance, accelerates lubricant degradation, increasing friction and reducing efficiency. Dust carried by wind can contaminate the lubricant, leading to premature wear and diminished lubrication performance [6]. In addition, unsteady wind forces generate impact loads and variable torque throughout the transmission chain, promoting fatigue in components, particularly in the gearbox, which is often the first to fail [7]. Another contributing factor is the mechanical contact between transmission elements, which increases surface wear and fatigue [8]. Altogether, these challenges contribute to a high failure rate, potential power outages, safety hazards, and considerable economic losses [9; 10]. Monitoring data history has shown that this system accounts for 65% of all turbine shutdowns [11]. To reduce these interruptions, a portion of the generation cost is allocated to the operations and maintenance (O&M) department. This sector represents between 15% and 20% of total costs for onshore turbines and between 25% and 35% for offshore ones [7]. Various maintenance strategies have been adopted to address these challenges. Corrective maintenance is implemented after a fault occurs, involving the repair or replacement of defective components. While this approach can address issues, it does not prevent unexpected downtime, and for critical components, the resulting damage can be incalculable [12]. Another approach is systematic preventive maintenance, which involves replacing components before they reach the end of their useful life, ideally during non-work hours. Although this helps to avoid unexpected downtime, it results in component replacement regardless of their actual condition [13]. Condition-based maintenance allows for the replacement of defective components at the optimal time, just before the end of their useful life, according to their condition. However, this requires effective monitoring systems to assess the state of the component [14]. Finally, predictive maintenance uses the current condition of the components to estimate their useful life. This approach relies on data collected through various monitoring systems, enabling proactive interventions and improving operational efficiency [7]. The O&M department plays a critical role in ensuring safe and stable system operation by deploying effective monitoring tools [15].