Time-Frequency Analysis Based on Improved Variational Mode Decomposition and Teager Energy Operator for Rotor System Fault Diagnosis

Table 2

Comparison of characteristic frequency average amplitude by HHT and IVMD-TEO.

Rotor fault type	Fault frequency components (center frequency/Hz)	⁢Extracted characteristic frequency average amplitude
		HHT (μm)	IVMD-TEO (μm)	Improved ratio (%)
Rub-impact	(56)	—	3.88	New
	(84)	—	4.13	New
	(112)	—	3.50	New
Oil-whirl	(14)	40.13	54.38	35.5
	1X (29)	27.38	30.75	12.3
	(43)	—	3.38	New
Oil-whip	(11.5)	3.50	4.25	21.4
	(23)	88.13	99.25	12.6
	(36.5)	—	7.25	New
	(48)	61.63	60.88
	(71)	—	5.88	New
	(84.5)	—	2.75	New
	(96)	—	3.50	New
	(119)	—	3.13	New

Note: “—” represents no extracted fault frequency by HHT and “new” represents new extracted fault frequency by IVMD-TEO.