H∞ Robust Controller for a Long VSC-HVDC Link Connected to a Weak Grid.

Rashed, Mohamed; Abulanwar, El-Sayed Mohamed Mohamed; Youssef, Fathi M. H.

doi:10.21608/bfemu.2010.123602

H∞ Robust Controller for a Long VSC-HVDC Link Connected to a Weak Grid.

Document Type : Research Studies

Authors

¹ Professor of Electrical Power Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura 35516., Egypt.

² Assistant Professor., Electrical Power Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt.

³ Electrical Power Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura 35516., Egypt.

10.21608/bfemu.2010.123602

Abstract

Owlng to their high dynamic performance and flexible control features, HVDC systems are widely employed in power systems for dynamic characteristics improvement. This paper presents a decentralized robust control scheme for a VSC-HVDC transmission system. The VSC-HVDC system is used to connect a weak AC gird to a strong power system using a long DC link The robust multivariable H-infinity H_∞ control approach is adopted for the design of the weak grid side controller in order to achieve robust stability and superior dynamic performance under large uncertainty in the short circuit ratio SCR of the weak grid. Small-signal modeling and step response Analysis are used to design the system controllers under different operating conditions and wide range of SCR variation. Furthermore, the His control system results are compared to that of a well designed PI based control system. The obtained results demonstrate robust dynamic performance under various operating conditions and Large SCR variation.

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