Open AccessPower flow modelling to UHVDC line and its hierarchical connection mode
Author(s) -
Li Shenghu,
Wu Zhengyang,
Huang Jiejie
Publication year - 2018
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2017.0851
Subject(s) - jacobian matrix and determinant , converters , line (geometry) , power flow , power (physics) , high voltage direct current , connection (principal bundle) , control theory (sociology) , voltage , electrical engineering , mode (computer interface) , topology (electrical circuits) , flow (mathematics) , engineering , direct current , electric power system , electronic engineering , computer science , mathematics , physics , mechanical engineering , mechanics , geometry , control (management) , quantum mechanics , artificial intelligence , operating system
At one converter station, compared with the high‐voltage direct current (HVDC) line, the conversion units of the ultra HVDC (UHVDC) line are doubled and controlled independently, possibly yielding the unbalanced operation modes, separate settings to the DC variables of the positive and negative poles, and different equivalent powers and mismatch equations (MEs). Under the hierarchical connection mode (HCM), the inverters connect two AC voltages. Hence, the operation modes are not the same as the UHVDC line, and the parameters of the inverters at the high and low terminals are to be set independently. In this study, the power flow model of the UHVDC line is newly proposed. Considering the unbalanced modes and the HCM, the DC variables, the equivalent powers of the converters, and the MEs are decided. The elements of the extended Jacobian matrix are defined. The initial values and specified values are derived. The modified IEEE RTS system and a provincial system in the eastern China are applied to validate the feasibility and accuracy of the proposed models. The research provides the basis for the operation and economic dispatch of the AC/UHVDC systems.