Mathematical Problems in Engineering

Research Article

Online Monitoring and Early Warning of Subsynchronous Oscillation Using Levenberg–Marquardt and Backpropagation Algorithm Combined with Sensitivity Analysis and Principal Component Analysis

PCA method for processing input parameters.


Sample number		1	2	3	4	5	6	7	8	9

Original input parameters	P_th/Q_th	1.0/0.2	0.5/0.2	1.0/0.2	1.0/0.2	1.0/0.2	1.0/0.2	1.0/0.2	1.0/0.2	1.0/0.2
	P_DFIG/Q_DFIG	1.0/0.1	1.0/0.1	0.5/0.1	1.0/0.1	1.0/0.1	1.0/0.1	1.0/0.1	1.0/0.1	1.0/0.1
	P_HVDC/Q_HVDC	−1.0/0.2	−1.0/0.2	−1.0/0.2	−0.7/0.2	−1.0/0.2	−1.0/0.2	−1.0/0.2	−1.0/0.2	−1.0/0.2
	K_C	1	1	1	1	3	1	1	1	1
	K_{I_DFIG}	0.16	0.16	0.16	0.16	0.16	0.7	0.16	0.16	0.16
	K_{P_DFIG}	0.3	0.3	0.3	0.3	0.3	0.3	0.7	0.3	0.3
	K_{I_HVDC}	20	20	20	20	20	20	20	100	20
	K_{P_HVDC}	6500	6500	6500	6500	6500	6500	6500	6500	3250
Parameters after PCA dimensionality reduction	Z1	−1.40	−0.38	1.56	0.49	−1.06	−1.41	3.68	0.25	−1.73
	Z2	0.90	−0.32	3.66	−0.78	−0.98	−0.88	−1.43	−0.76	0.58
	Z3	2.07	0.10	−1.12	−0.47	−1.35	−1.23	1.15	−0.51	1.36
	Z4	−0.11	−0.01	0.03	0.02	−2.24	2.25	0.12	0.02	−0.08
	Z5	−0.30	0.74	−0.15	1.06	−0.87	−0.85	−0.74	1.07	0.04
	Z6	−0.35	0.12	0.01	−0.20	−0.02	−0.02	0.06	0.02	0.37