Speed Sensor-Less Control System of Surface-Mounted Permanent Magnet Synchronous Motor Based on Adaptive Feedback Gain Supertwisting Sliding Mode Observer

Table 5

THD and back-EMF fluctuation.

Result	SMO	STA-SMO	AFG-STA-SMO	Unit
THD (a)	8.92	8.62	8.68	%
THD (b)	1.84	1.27	1.24	%
THD (c)	1.50	4.28	3.84	%
Back-EMF fluctuation (a)	-31.8~-33.725	-32.92~-33	-32.91~-32.92	V
Back-EMF fluctuation (b)	-72~-72.36	-72.6~-72.76	-72.685~-72.695	V
Back-EMF fluctuation (c)	143~145	146.35~146.6	46.22~146.23	V