TY - JOUR
T1 - Frequency converter-driven oscillations in weak grids
T2 - explanation and damping improvement
AU - Wu, Guanglu
AU - Sun, Huadong
AU - Zhao, Bing
AU - Xu, Shiyun
AU - Zhang, Xi
AU - Egea Àlvarez, Agustí
AU - Wang, Shanshan
AU - Li, Gen
AU - Li, Yingbiao
AU - Zhou, Xiaoxin
N1 - © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
PY - 2021/6/30
Y1 - 2021/6/30
N2 - Low-frequency oscillations have been reported in several weak-grids-connected voltage-source-converter(VSC) systems. Although efforts have been devoted to understand the parametric and sensitivity impact of the VSC controller gains, a general formulation of the oscillation mechanism is still missing. Using transfer function dynamic modelling approach, we find that the outer loop active power control’s bandwidth mainly determines the oscillation frequency. The PLL introduces a large phase lag around the frequency of the PLL bandwidth in weak grids which decreases the oscillation damping. A simple but effective PI+Clegg integrator (CI) compensator is proposed to replace the standard outer loop active power controller compensating the PLL’s phase delay and increase the oscillation damping. The results are verified in a real time digital simulator.
AB - Low-frequency oscillations have been reported in several weak-grids-connected voltage-source-converter(VSC) systems. Although efforts have been devoted to understand the parametric and sensitivity impact of the VSC controller gains, a general formulation of the oscillation mechanism is still missing. Using transfer function dynamic modelling approach, we find that the outer loop active power control’s bandwidth mainly determines the oscillation frequency. The PLL introduces a large phase lag around the frequency of the PLL bandwidth in weak grids which decreases the oscillation damping. A simple but effective PI+Clegg integrator (CI) compensator is proposed to replace the standard outer loop active power controller compensating the PLL’s phase delay and increase the oscillation damping. The results are verified in a real time digital simulator.
KW - weak grids
KW - low frequency oscillations
KW - oscillation damping
UR - https://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=59
M3 - Article
JO - IEEE Transactions on Power Systems
JF - IEEE Transactions on Power Systems
SN - 0885-8950
ER -