The use of analytical converter loss formula to eliminate DC slack/droop bus iteration in sequential AC-DC power flow algorithm. (May 2022)

• Record Type: Journal Article
• Authors: Zhang, Yuanshi; Meng, Xuekun; Malik, Abrar; Wang, Liwei
• Is Part Of: International journal of electrical power & energy systems. Volume 137(2022)
• Publication Date: 2022-05
• Subjects: AC-DC grid -- Converter loss -- Droop control -- High voltage direct current (HVDC) -- Modular multilevel converter (MMC) -- Sequential power flow -- Slack bus iteration (SBI); Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2021.107596
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: The proposed sequential power flow algorithm eliminates the SBI/DBI iteration loop. The proposed sequential power flow algorithm preserves the power flow calculation accuracy. The coefficients of an analytical converter loss formula for MMCs are derived. Abstract: In conventional sequential AC-DC power flow algorithm, DC slack bus iteration (SBI) or droop bus iteration (DBI) is used to update converter loss of the DC slack or droop buses in each AC-DC power flow iteration. The use of SBI or DBI causes additional computational burden on top of the iterative solution of AC-DC power flow, reducing the computational efficiency of the power flow. This letter proposes a novel method to eliminate the SBI or DBI while preserving the accuracy of power flow algorithm. Moreover, a generalized converter loss formula for modular multilevel converters with different submodule types, i.e., half-bridge, full-bridge or mixed half- and full-bridge is derived to eliminate the SBI or DBI. The proposed algorithm is validated using two interconnected AC-DC grid consisting of the IEEE 39-bus AC grid and a 6-terminal DC grid and the IEEE 300-bus AC grid integrated with a 10-terminal DC grid, respectively.