Rüzgar türbinlerinde kestirimci bakım stratejisi için arıza modları ve etkilerinin analizi
Analysis of failure modes and effects for predictive maintenance strategy in wind turbines
Yazar: MERT ÖZHAN
Danışman: PROF. DR. ÖNDER GÜLER
İstanbul Teknik Üniversitesi / Enerji Enstitüsü / Enerji Bilim ve Teknoloji Ana Bilim Dalı / Enerji Bilim ve Teknoloji Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Enerji = Energy

Özet:
Rüzgar enerjisi santrallerinin sayı ve kapasite olarak artışı, Türkiye'de ve dünya genelinde rüzgar enerjisi sektörünün önemini artırmıştır. Bu artış, rüzgar enerjisinin elektrik enerjisi arzındaki rolünün büyümesinden kaynaklanmaktadır. Bu durum, enerji verimliliğini optimize etme ve maliyet etkin bakım yöntemlerinin geliştirilmesi konusunda acil bir ihtiyaç yaratmıştır. Bu çalışma, rüzgar enerjisi sektörünün bu yeni dönemde karşı karşıya olduğu zorlukları ve fırsatları ele alarak, sektörün sürdürülebilir büyümesine katkıda bulunmayı amaçlamaktadır. 
Tez çalışması kapsamında, işletmede olan pilot bir rüzgar enerjisi santralinden yola çıkarak; rüzgar türbinlerinin ana bileşenlerinin arıza modları ve bu arızaların etkileri detaylı bir şekilde incelenmiştir. Yapılan çalışmalarda jeneratör, pitch ve yaw sistemleri, dişli kutusu, rotor kanatları ve ana şaft gibi kritik bileşenler üzerinde durulmuştur. Her bileşen için, arıza modları ve bu modların sistem üzerindeki etkileri kapsamlı bir şekilde tanımlanmış ve analiz edilmiştir. Arıza modlarının sıklığı ve sistem üzerindeki ciddiyeti dikkate alınarak, her bileşen için bir kritiklik sıralaması yapılmıştır.
Rüzgar türbinlerinin ana bileşenlerinde meydana gelen arıza modları incelenerek, kritiklik seviyeleri belirlenmesi amaçlanmıştır. Tezin ilk bölümü, rüzgar enerjisi ve rüzgar türbinlerinin temel prensiplerine odaklanmaktadır. Ardından kestirimci bakımın temel kavramları incelenerek, rüzgar türbini güvenilirliği ile ilgili literatürdeki güncel gelişmeleri özetlemektedir. Tezin sonraki bölümlerinde ise çeşitli kestirimci bakım stratejileri sunulmuş, detaylı bir Arıza Modu Etkisi ve Kritiklik Analizi (FMECA) sunulmuştur.
Jeneratör sistemine özel olarak odaklanılarak, stator, rotor, yataklar ve jeneratör tutucusu gibi bileşenlerde meydana gelen arızalar detaylandırılmıştır. Özellikle jeneratörün fazlar arasındaki kısa devre ve yataklardaki düşük yağlama en önemli arıza türleri olarak belirlenmiştir. Bu arızaların erken tespiti, hasarın azaltılmasına ve bileşen ömrünün uzatılmasına katkı sağlayacaktır.
Pitch ve yaw sistemlerinin arıza modları da detaylı bir şekilde incelenmiş, bu sistemlerde ortaya çıkan başlıca sorunlar belirlenmiştir. Pitch sisteminde, hidrolik valfler ve motor pompası ile ilgili sorunlar öne çıkmaktadır. Yaw sistemlerinde ise yağlama eksikliği gibi sorunlar dikkat çekmektedir.
Dişli kutusunun FMECA analizi, yağlama sorunlarına ve güç aktarımıyla ilgili bileşenlerdeki arızalara odaklanmıştır. Rotor kanatlarının aerodinamik tasarımı ve yıldırıma karşı koruma sistemleri de incelenmiş, özellikle hava koşullarından kaynaklanan arızalar belirlenmiştir. Ana şaft düzenlemesi de incelenmiş, en kritik arızalar olarak rulman ve mil kaplin sorunları belirlenmiştir. Son olarak, konvertör sistemi ve enerji kayıplarının analizi yapılmış, enerji üretimindeki kayıpların azaltılmasına yönelik öneriler geliştirilmiştir.

Abstract:
In recent years, the wind energy sector in Turkey and across the globe has experienced a significant technological evolution, marked by advancements in turbine efficiency and energy storage solutions. In Turkey, the rapid development of wind farms, characterized by an increase in both the quantity and the capacity of turbines, demonstrates a commitment to harnessing wind as a key renewable resource. This trend is in line with global movements towards sustainable energy, where wind power is increasingly recognized for its efficiency in large-scale electricity production and its reduced environmental footprint. Technological innovations in aerodynamic blade design, improved gearbox durability, and enhanced power electronics have played a crucial role in increasing the efficiency and reliability of wind turbines. Furthermore, the integration of smart grid technologies and IoT applications in wind energy systems has enabled more precise monitoring and predictive maintenance, leading to higher operational efficiency and reduced downtime. The sector's expansion reflects a broader shift towards renewable energy sources, underlining the importance of continuous research and development in wind technology to meet growing energy demands while minimizing environmental impact.
This thesis delves into the intricate workings of wind turbines, which are marvels of modern engineering designed to harness the kinetic energy of wind. At their core, these turbines operate on the principle of converting wind energy into mechanical power, which is subsequently transformed into electricity. The process begins with the turbine's blades, elegantly crafted to capture wind effectively. These blades are connected to a rotor, which turns the low-speed shaft. The gearbox, a pivotal component, then steps up the low rotational speed of the shaft to a higher speed conducive for electricity generation. The generator, connected to the high-speed shaft, plays the crucial role of converting this mechanical energy into electrical energy.
Additionally, the thesis examines the sophisticated ancillary systems that augment the turbine's efficiency. The nacelle, housing critical components like the gearbox and generator, also contains control systems vital for operational safety and efficiency. The yaw mechanism, enabling the turbine to pivot and face the wind, and the pitch system, adjusting blade angles for optimal wind capture, are dissected to understand their contribution to maximizing energy yield. Furthermore, the tower, supporting the nacelle and rotor assembly, is explored for its structural integrity and design considerations in different environmental contexts.
In essence, this thesis provides a comprehensive overview of the multiple components and their synergistic functions in a wind turbine, emphasizing the importance of each in the efficient conversion of wind to electrical energy. This exploration is pivotal in understanding the complexities of wind turbine technology and the advancements necessary to optimize their performance and sustainability in the renewable energy sector.
In the realm of wind energy, the efficacy of maintenance regimes plays a critical role in determining the operational reliability and efficiency of wind turbines. These complex mechanical structures, consisting of intricate components like aerodynamic blades, sophisticated gearboxes, and high-precision generators, demand meticulous and strategic maintenance approaches. The cornerstone of effective turbine maintenance lies in adopting condition-based monitoring (CBM) strategies, which pivot on the use of advanced diagnostic tools such as strain gauges, accelerometers, and oil particle counters. These technologies enable the early detection of abnormalities like blade erosion, gearbox misalignment, or bearing wear, long before they escalate into catastrophic failures.
Furthermore, the integration of predictive analytics into maintenance protocols harnesses the power of data science and machine learning algorithms. This approach facilitates the anticipation of potential component failures by analyzing trends and patterns in operational data, significantly minimizing unscheduled downtimes. For instance, vibrational analysis can preemptively signal the need for bearing replacements, while thermal imaging can identify overheating issues in electrical components.
In addition, the advent of remote monitoring and control systems has revolutionized wind turbine maintenance. These systems provide real-time data from each turbine, allowing for remote diagnostics and immediate responses to operational discrepancies. This level of control not only enhances the safety of maintenance personnel by reducing the need for on-site inspections in potentially hazardous conditions but also streamlines the overall maintenance process, contributing to the turbines' extended lifecycles and sustained energy output.
As wind energy continues its upward trajectory in the global energy market, the emphasis on refined and technologically advanced maintenance practices becomes increasingly paramount. These practices not only fortify the reliability and efficiency of wind turbines but also bolster the overall sustainability and economic feasibility of wind energy projects.
This thesis addresses the significant growth in the number and capacity of Wind Energy Plants in Turkey and globally, highlighting the increased importance of the wind energy sector. This growth is attributed to the expanding role of wind energy in the electricity supply chain, underlining the urgent need for optimizing energy efficiency and developing cost-effective maintenance strategies. The study aims to contribute to the sustainable growth of the wind energy sector by exploring the challenges and opportunities it faces in this new era.
Focusing on an operational pilot wind energy plant, the thesis conducts a detailed examination of the failure modes and their effects on the main components of wind turbines. Critical components such as generators, pitch and yaw systems, gearboxes, rotor blades, and main shafts are thoroughly investigated. For each component, the failure modes and their impacts on the system are comprehensively defined and analyzed. A criticality ranking for each component is established based on the frequency of failure modes and their severity on the system.
The primary objective of this research is to study the failure modes occurring in the main components of wind turbines and to determine their criticality levels. The initial section of the thesis focuses on the basic principles of wind energy and wind turbines. Following this, the fundamental concepts of predictive maintenance are reviewed, summarizing the current developments in wind turbine reliability found in the literature. Subsequent sections of the thesis present various predictive maintenance strategies and a detailed Failure Mode, Effects, and Criticality Analysis (FMECA).
Particular attention is given to the generator system, detailing failures in components like the stator, rotor, bearings, and generator holder. Critical failure types, such as short circuits between generator phases and inadequate lubrication in bearings, are identified as primary concerns. Early detection of these failures can significantly reduce damage and extend the component's lifespan.
The failure modes of the pitch and yaw systems are also meticulously examined, identifying the main issues in these systems. For the pitch system, problems related to hydraulic valves and motor pumps are highlighted. In yaw systems, issues such as lubrication deficiencies are noted.
The FMECA of the gearbox focuses on lubrication issues and failures related to power transmission components. The aerodynamic design of rotor blades and their lightning protection systems are examined, particularly identifying failures caused by weather conditions. The main shaft arrangement is analyzed, with bearing and shaft coupling problems identified as the most critical failures.
Lastly, an analysis of the converter system and energy losses is conducted, proposing recommendations to reduce energy production losses. This study evaluates the effects of various component failures on energy losses, aiming to enhance the operational efficiency of wind turbines. This research significantly contributes to the development of maintenance and repair strategies for wind turbines, supporting the sector's progress toward sustainable energy production.