Reliability calculation of AC/DC hybrid distribution network with a solid-state transformer

• Main Authors: Xinxing Xu, Nengling Tai, Yan Hu, Wei Wang, Fenglei Zheng, Wenzhi He
• Format: Article
• Language: English
• Published: Wiley 2019-02-01
• Series: The Journal of Engineering
• Subjects: power distribution control; power system reliability; distributed power generation; reliability; power distribution reliability; power grids; distribution networks; power transmission reliability; solid-state transformer; DC loads; traditional 10 kV AC distribution network; AC/DC hybrid distribution network structure; 10 kV DC; 380 V AC four voltage levels; voltage 10.0 kV; voltage 375.0 V; voltage 380.0 V
• Online Access: https://digital-library.theiet.org/content/journals/10.1049/joe.2018.8385

With extensive access of distributed energy resources and DC loads, the traditional 10 kV AC distribution network has greatly increased the number of converters and reduced the reliability of power supply. A solid-state transformer (SST) containing AC and DC terminals to build AC/DC hybrid distribution networks has become the focus of the current research. This study presents an AC/DC hybrid distribution network structure with 10 kV AC, 10 kV DC, ±375 V DC, and 380 V AC four voltage levels. In this network, the load is data centre, which needs high security for power supply reliability. According to the characteristics of this network, this study takes the reliability evaluation by using the minimum path set method and the state enumeration method, and the reliability of this new structure with SST is calculated. Through the study of a numerical example, the results show that after adding the multi-terminal SST, the reliability of the AC/DC hybrid distribution network is suitable for data centre load, and the quantity of the converters can decrease.