Component matching chirplet transform via frequency-dependent chirp rate for wind turbine planetary gearbox fault diagnostics under variable speed condition

Abstract

A component matching chirplet transform (CMCT) via frequency-dependent chirp rate with high time-frequency (TF) resolution is proposed for wind turbine planetary gearbox (WTPG) fault diagnostics under variable speed condition. The challenge of identifying fault-related frequencies with small intervals, due to the time-varying rotational speed and complex structure of WTPG, can be well addressed. Unlike conventional chirplet transform, CMCT can generate a family of frequency-dependent chirplets, which can match all frequency components with a sufficiently high TF resolution. Furthermore, this proposed method does not require any prior knowledge. The effectiveness of CMCT is validated by a numerical simulation and an experimental data collected from a wind turbine drivetrain test rig.