Introducing MRAC-PSS-VI to Increase Small-Signal Stability of the Power System after Wind Power Integration

Table 3

The eigenvalues of the system with different controllers.

Mode	Without the controller			With the PSS			Dominant states
	λ	f (Hz)	ξ (%)	λ	f (Hz)	ξ (%)
1	−0.651 ± j6.547	1.042	9.897	−0.651 ± j6.547	1.042	9.897	G1, G2
2	−0.620 ± j6.393	1.017	9.658	−0.615 ± j6.390	1.017	9.580	G3, G4
3	−0.300 ± j3.135	0.499	9.532	−0.368 ± j3.180	0.506	11.521	G1–G4
4	−0.513 ± j3.059	0.487	16.539	−0.396 ± j3.359	0.535	11.710	G1–G4, DFIG
Mode	With the PSS-VI			With MRAC-PSS-VI			Dominant states
	Λ	f/Hz	ξ (%)	λ	f/Hz	ξ (%)
1	−0.651 ± j6.547	1.042	9.897	−0.670 ± j6.359	1.012	10.479	G1, G2
2	−0.620 ± j6.393	1.017	9.658	−1.778 ± j6.106	0.972	27.954	G3, G4
3	−0.298 ± j3.137	0.499	9.464	−0.304 ± j3.033	0.483	9.968	G1–G4
4	−0.689 ± j3.482	0.554	19.417	−0.967 ± j3.546	0.564	26.305	G1–G4, DFIG