An Improved Quantitative Analysis Method of Oscillation Mode for DFIG-based Wind Power Base with LCC-HVDC Transmission Considering Frequency Coupling Characteristic

The line-commutated converter-based high-voltage direct-current (LCC-HVDC) transmission has become one of the main forms to deliver wind power in China. However, due connections a large number electronic devices (PEDs), there emerges risk sub/super-synchronous oscillations DFIG-based base with LCC-HVDC transmission. existing multi-node system analysis methods have ignored frequency coupling characteristic (FCC) PEDs, unable obtain accurate oscillation characteristics. Besides, relationship between and multi-level factors not been revealed yet. Therefore, this paper proposes an improved quantitative method mode which considers FCC on basis admittance network model. Firstly, impedance model considering is established. Then, proposed its steps are as follows. 1) To establish transfer function matrix FCC, determine stability accurately by dominant mode; 2) define node participation factor, effect frequency, quantify degree each identify origin weak point oscillation; 3) carry out sensitivity analysis. Finally, characteristics laws studied, time-domain simulations MATLAB/Simulink validate analytical results.