Wind Turbine Main Bearing: A Mini Review of Its Failure Modes and Condition Monitoring Techniques

Condition monitoring of wind turbine components is critical to operational effectiveness and efficiencies, which becomes vital at the utility scale level. Among other components, the main bearing has been identified as a critical component. This is due to its operating conditions and loading, which deviate from other bearings in the wind turbine power train. The growing improvement on wind turbine production capacity has consequently improved condition monitoring approaches to its critical components. This study presents a mini-review of wind turbine failure modes and condition monitoring strategies for its main bearing. A brief overview of vital wind turbine components is presented, focusing on the main bearing. The study summarizes the failure modes of the main bearing and identifies potential condition monitoring methods for the main bearing, their strengths and limitations. Finally, prospects for future research in the condition monitoring of wind turbine main bearing were highlighted.

I. Introduction

Wind energy is among the dominant renewable energy sources globally [1] and is poised to remain dominant as evidenced by its annual progressive growth. A trend of global installed capacities of wind energy systems from 2011 to 2020 (Fig. 1) shows that installed capacities of wind energy systems have more than tripled within the last decade [2]. As seen from the chart, despite the COVID pandemic in 2019, installed capacities of wind energy systems took a steeper trend. Similar statistics presented in Figure 2 show that wind energy had 46 % of the global share of installed capacities of renewable energy sources in 2020. The global installed capacity of wind energy systems was 732 GW (in 2020), with offshore installations taking above 90 % of this. Dao et al., [2] project that with progressive investments in wind energy systems, global installed capacities of wind turbines may reach 1 TW by 2030. This projection represents more than a tenfold increase from present-day installed capacities. Critical to this geometric increase is the reliability of wind turbines and their sub-systems. Fig. 1.

Global installed capacities of wind turbines from 2011 to 2020 (sourced from [3]).

Fig. 2.

Global share of installed renewable energy sources in 2020 ((sourced from [3]).