Design of flexible DC-SOP toward four-quadrant power flow control in bipolar distribution networks

Chengjia Zhang; Xiaodong Yang; Lijian Ding; Yue Yang; Helong Li; Zhiqing Yang; Qiuwei Wu; Jinyu Wen

doi:10.1109/tsg.2026.3651935

Design of flexible DC-SOP toward four-quadrant power flow control in bipolar distribution networks

Chengjia Zhang
, Xiaodong Yang
, Lijian Ding
, Yue Yang
, Helong Li
, Zhiqing Yang
, Qiuwei Wu
, Jinyu Wen

School of Electronics, Electrical Engineering and Computer Science

Research output: Contribution to journal › Letter › peer-review

2 Citations (Scopus)

Abstract

This letter introduces the direct current soft open point (DC-SOP), which is a bipolar DC-DC converter designed to achieve independent four-quadrant power flow control in bipolar DC distribution networks (BDDNs). For the first time, asymmetric dual active bridges are employed to connect the four-quadrant ports, ensuring a flexible power channel to realize flexible power transfer between branches and poles. Bidirectional shift modulation strategy and four-quadrant decoupling facilitate independent power control, effectively mitigating branch overload and inter-pole power unbalance. To improve model linearization accuracy, a refined relaxation method is proposed, providing theoretical guidance for DC-SOP applications in BDDNs. The effectiveness of the proposed method is validated in ±10kV BDDNs with 33 nodes and 123 nodes.

Original language	English
Number of pages	1
Journal	IEEE Transactions on Smart Grid
DOIs	https://doi.org/10.1109/tsg.2026.3651935
Publication status	Early online date - 12 Jan 2026

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title = "Design of flexible DC-SOP toward four-quadrant power flow control in bipolar distribution networks",

abstract = "This letter introduces the direct current soft open point (DC-SOP), which is a bipolar DC-DC converter designed to achieve independent four-quadrant power flow control in bipolar DC distribution networks (BDDNs). For the first time, asymmetric dual active bridges are employed to connect the four-quadrant ports, ensuring a flexible power channel to realize flexible power transfer between branches and poles. Bidirectional shift modulation strategy and four-quadrant decoupling facilitate independent power control, effectively mitigating branch overload and inter-pole power unbalance. To improve model linearization accuracy, a refined relaxation method is proposed, providing theoretical guidance for DC-SOP applications in BDDNs. The effectiveness of the proposed method is validated in ±10kV BDDNs with 33 nodes and 123 nodes.",

author = "Chengjia Zhang and Xiaodong Yang and Lijian Ding and Yue Yang and Helong Li and Zhiqing Yang and Qiuwei Wu and Jinyu Wen",

year = "2026",

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day = "12",

doi = "10.1109/tsg.2026.3651935",

language = "English",

journal = "IEEE Transactions on Smart Grid",

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TY - JOUR

T1 - Design of flexible DC-SOP toward four-quadrant power flow control in bipolar distribution networks

AU - Zhang, Chengjia

AU - Yang, Xiaodong

AU - Ding, Lijian

AU - Yang, Yue

AU - Li, Helong

AU - Yang, Zhiqing

AU - Wu, Qiuwei

AU - Wen, Jinyu

PY - 2026/1/12

Y1 - 2026/1/12

N2 - This letter introduces the direct current soft open point (DC-SOP), which is a bipolar DC-DC converter designed to achieve independent four-quadrant power flow control in bipolar DC distribution networks (BDDNs). For the first time, asymmetric dual active bridges are employed to connect the four-quadrant ports, ensuring a flexible power channel to realize flexible power transfer between branches and poles. Bidirectional shift modulation strategy and four-quadrant decoupling facilitate independent power control, effectively mitigating branch overload and inter-pole power unbalance. To improve model linearization accuracy, a refined relaxation method is proposed, providing theoretical guidance for DC-SOP applications in BDDNs. The effectiveness of the proposed method is validated in ±10kV BDDNs with 33 nodes and 123 nodes.

AB - This letter introduces the direct current soft open point (DC-SOP), which is a bipolar DC-DC converter designed to achieve independent four-quadrant power flow control in bipolar DC distribution networks (BDDNs). For the first time, asymmetric dual active bridges are employed to connect the four-quadrant ports, ensuring a flexible power channel to realize flexible power transfer between branches and poles. Bidirectional shift modulation strategy and four-quadrant decoupling facilitate independent power control, effectively mitigating branch overload and inter-pole power unbalance. To improve model linearization accuracy, a refined relaxation method is proposed, providing theoretical guidance for DC-SOP applications in BDDNs. The effectiveness of the proposed method is validated in ±10kV BDDNs with 33 nodes and 123 nodes.

U2 - 10.1109/tsg.2026.3651935

DO - 10.1109/tsg.2026.3651935

M3 - Letter

SN - 1949-3053

JO - IEEE Transactions on Smart Grid

JF - IEEE Transactions on Smart Grid

ER -

Design of flexible DC-SOP toward four-quadrant power flow control in bipolar distribution networks

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