TY - JOUR
T1 - Impedance Modeling and Stability Analysis of Grid-Connected DFIG-based Wind Farm with a VSC-HVDC
AU - Sun, Kun
AU - Yao, Wei
AU - Fang, Jiakun
AU - Ai, Xiaomeng
AU - Wen, Jinyu
AU - Cheng, Shijie
PY - 2020/6
Y1 - 2020/6
N2 - A new type of subsynchronous oscillation (SSO) has been observed recently in double-fed induction generator (DFIG)-based wind farm integrated via voltage source converter-based HVdc (VSC-HVdc) system. However, the mechanism of this emerging oscillation is not entirely understood. In this paper, the impedance models of DFIG with and without considering the phase-locked loop (PLL) dynamics are both derived. Then, the impedance-based simplified equivalent circuit of the multiple DFIGs interfaced with VSC-HVdc system is established. This model can be further represented as the RLC series resonance circuit to quantify the start-oscillating condition intuitively. The theoretical analysis results show that DFIGs behave as an inductance in series with a negative resistance at the resonance point, whose interaction with wind farm side VSC (WFVSC) (regard as a resistance-capacitance) constitutes an equivalent RLC resonance circuit with negative resistance. Therefore, the oscillation tends to occur due to the negative damping. In addition, the impact of various factors including number of grid-connected DFIG-wind turbines (WTs), wind speed, and parameters of PI controllers and PLL on the SSO characteristics is analyzed based on the proposed simplified model. Finally, the correctness of the theoretical analysis is validated by both the time-domain simulation and hardware-in-loop experiments.
AB - A new type of subsynchronous oscillation (SSO) has been observed recently in double-fed induction generator (DFIG)-based wind farm integrated via voltage source converter-based HVdc (VSC-HVdc) system. However, the mechanism of this emerging oscillation is not entirely understood. In this paper, the impedance models of DFIG with and without considering the phase-locked loop (PLL) dynamics are both derived. Then, the impedance-based simplified equivalent circuit of the multiple DFIGs interfaced with VSC-HVdc system is established. This model can be further represented as the RLC series resonance circuit to quantify the start-oscillating condition intuitively. The theoretical analysis results show that DFIGs behave as an inductance in series with a negative resistance at the resonance point, whose interaction with wind farm side VSC (WFVSC) (regard as a resistance-capacitance) constitutes an equivalent RLC resonance circuit with negative resistance. Therefore, the oscillation tends to occur due to the negative damping. In addition, the impact of various factors including number of grid-connected DFIG-wind turbines (WTs), wind speed, and parameters of PI controllers and PLL on the SSO characteristics is analyzed based on the proposed simplified model. Finally, the correctness of the theoretical analysis is validated by both the time-domain simulation and hardware-in-loop experiments.
KW - Doubly fed induction generators
KW - Wind farms
KW - Phase locked loops
KW - Integrated circuit modeling
KW - Impedance
KW - Power conversion
KW - DFIG
KW - VSC-HVDC
KW - subsynchronous oscillation
KW - impedance-based method
KW - phase locked loop
KW - wind farm
KW - DFIG
KW - VSC-HVDC
KW - Subsynchronous oscillation
KW - Impedance-based method
KW - Phase locked loop
KW - Wind farm
KW - wind farm
KW - impedance-based method
KW - subsynchronous oscillation (SSO)
KW - voltage source converter (VSC)-HVdc
KW - Double-fed induction generator (DFIG)
KW - phase-locked loop (PLL)
UR - http://www.scopus.com/inward/record.url?scp=85084730453&partnerID=8YFLogxK
U2 - 10.1109/JESTPE.2019.2901747
DO - 10.1109/JESTPE.2019.2901747
M3 - Journal article
SN - 2168-6777
VL - 8
SP - 1375
EP - 1390
JO - IEEE Journal of Emerging and Selected Topics in Power Electronics
JF - IEEE Journal of Emerging and Selected Topics in Power Electronics
IS - 2
M1 - 8653346
ER -