TY - JOUR
T1 - Modeling and Stability Assessment of Single-Phase Grid Synchronization Techniques
T2 - Linear Time-Periodic versus Linear Time-Invariant Frameworks
AU - Golestan, Saeed
AU - Guerrero, Josep M.
AU - Vasquez, Juan
PY - 2019/1
Y1 - 2019/1
N2 - The grid synchronization unit, which is often based on a frequency-locked loop (FLL) or a phase-locked loop (PLL), highly affects the power converter performance and stability, particularly under weak grid conditions. It implies that a careful stability assessment of grid synchronization techniques (GSTs) is of vital importance. This task is most often based on obtaining a linear time-invariant (LTI) model for the GST and applying standard stability tests to it. Another option is modeling and dynamics/stability assessment of GSTs in the linear time-periodic (LTP) framework, which has received a very little attention. In this letter, the procedure of deriving the LTP model for single-phase GSTs is first demonstrated. The accuracy of the LTP model in predicting the GST dynamic behavior and stability is then evaluated and compared with that of the LTI one. Two well-known single-phase GSTs, i.e., the second-order generalized integrator-based FLL (SOGI-FLL) and enhanced PLL (EPLL), are considered as the case studies.
AB - The grid synchronization unit, which is often based on a frequency-locked loop (FLL) or a phase-locked loop (PLL), highly affects the power converter performance and stability, particularly under weak grid conditions. It implies that a careful stability assessment of grid synchronization techniques (GSTs) is of vital importance. This task is most often based on obtaining a linear time-invariant (LTI) model for the GST and applying standard stability tests to it. Another option is modeling and dynamics/stability assessment of GSTs in the linear time-periodic (LTP) framework, which has received a very little attention. In this letter, the procedure of deriving the LTP model for single-phase GSTs is first demonstrated. The accuracy of the LTP model in predicting the GST dynamic behavior and stability is then evaluated and compared with that of the LTI one. Two well-known single-phase GSTs, i.e., the second-order generalized integrator-based FLL (SOGI-FLL) and enhanced PLL (EPLL), are considered as the case studies.
KW - Frequency locked loop (FLL)
KW - Generalized inverse Nyquist stability criterion
KW - Harmonic transfer function
KW - Linear time-periodic (LTP) systems
KW - Modeling
KW - Phase-locked loop (PLL)
KW - Single-phase systems
KW - Stability analysis
KW - Synchronization
UR - http://www.scopus.com/inward/record.url?scp=85046761043&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2018.2835144
DO - 10.1109/TPEL.2018.2835144
M3 - Journal article
AN - SCOPUS:85046761043
SN - 0885-8993
VL - 34
SP - 20
EP - 27
JO - IEEE Transactions on Power Electronics
JF - IEEE Transactions on Power Electronics
IS - 1
M1 - 8357505
ER -