TY - JOUR
T1 - A quadratic convex framework with bigger freedom for the stability analysis of a cyber-physical microgrid system
AU - He, Jing
AU - Liang, Yan
AU - Hao, Xiaohui
AU - Yang, Feisheng
AU - Pan, Quan
N1 - Publisher Copyright:
© 2023, Science China Press.
PY - 2023/2
Y1 - 2023/2
N2 - Information exchange between a microgrid central controller and local controllers is supported by low-bandwidth communication channels, leading to an inevitable delay with time-varying characteristics that adversely affect the microgrid dynamics and even cause instability. This study addresses the problem of stability analysis for a load frequency control (LFC) microgrid system with the interval time-varying delay. First, a modeling approach is proposed for the cyber-physical microgrid, in which the physical interconnection between the cyber-physical components is established. Given that a quadratic function is often introduced in stability analysis and the negative determination is crucial to reducing the conservatism, a novel quadratic convex framework with adjustable free parameters that relaxes the quadratic function negative-determination conditions is developed. Next, the delay-dependent stability criterion of the cyber-physical LFC microgrid is obtained on the basis of augmented Lyapunov-Krasovskii functional and Bessel-Legendre inequality together with mixed convex combination techniques. This reduces the conservatism without requiring extra decision variables. Finally, two types of case studies demonstrate the merits of the proposed scheme.
AB - Information exchange between a microgrid central controller and local controllers is supported by low-bandwidth communication channels, leading to an inevitable delay with time-varying characteristics that adversely affect the microgrid dynamics and even cause instability. This study addresses the problem of stability analysis for a load frequency control (LFC) microgrid system with the interval time-varying delay. First, a modeling approach is proposed for the cyber-physical microgrid, in which the physical interconnection between the cyber-physical components is established. Given that a quadratic function is often introduced in stability analysis and the negative determination is crucial to reducing the conservatism, a novel quadratic convex framework with adjustable free parameters that relaxes the quadratic function negative-determination conditions is developed. Next, the delay-dependent stability criterion of the cyber-physical LFC microgrid is obtained on the basis of augmented Lyapunov-Krasovskii functional and Bessel-Legendre inequality together with mixed convex combination techniques. This reduces the conservatism without requiring extra decision variables. Finally, two types of case studies demonstrate the merits of the proposed scheme.
KW - cyber-physical microgrid
KW - load frequency control
KW - quadratic convex framework
KW - stability analysis
UR - http://www.scopus.com/inward/record.url?scp=85140945667&partnerID=8YFLogxK
U2 - 10.1007/s11432-021-3433-8
DO - 10.1007/s11432-021-3433-8
M3 - 文章
AN - SCOPUS:85140945667
SN - 1674-733X
VL - 66
JO - Science China Information Sciences
JF - Science China Information Sciences
IS - 2
M1 - 122202
ER -