Research on the Influence of Electrical Corrosion of Bearings on Wind Power

Nay Min Aung

2020-2023

Master in Mechanical Engineering

ABSTRACT

Wind power's installed capacity and power generation capability are growing rapidly, making it one of the most promising renewable energy sources. Wind turbines' propulsion systems and generator bearings play a vital role in power transmission and load support. The generator bearings cause electrical corrosion of bearings due to shaft current, resulting in bearing failure. Therefore, understanding the impact of electrical corrosion on generator shafts is to guarantee the dependability of wind power production. Specifically, the following are the most important findings and contributions of the work:

1. Based on analysis of SCADA data of generator bearing, electrical corrosion damage caused by shaft current, it is found that the abnormal change of bearing temperature is the precursor of electrical corrosion. Three algorithms extract useful feature information from high-dimensional information, and the generation forecasting model is introduced. Data currently available suggest that the bearing temperature of the wind power generator reaches more than 100 ̊C, which will result in bearing failure due to electrical corrosion.

2. The occurrence conditions of electric corrosion on the surface of the axial current bearing were simulated using a current-carrying tester, and research was done on the friction pair's response to axial current. It was found that the contact resistance reached 40m Ω when the voltage was 1V, and electrical corrosion occurred after 30 minutes.

3. Support Vector Machine-regression (SVM-reg), Long Short Term

Memory(LSTM), and Auto-regressive Integrated Moving Average Model

(ARIMA) models are used to compare the power generation of the two types of wind turbines based on the shaft current damage and normal wind turbine SCADA data. It is found that the typical wind turbine can generate 1.68 MW on average in 6 months, while the power generation of the shutdown wind turbine caused by electrical erosion is less than 50% of the typical wind turbine.

Keywords: electrical corrosion, bearing, wear, and contact resistance, algorithm, wind power