A Web-based power flow calculation of large-scale power systems embedded with VSC-based HVDC systems

This paper presents a power flow model of a voltage-source converter-based (VSC-based) HVDC transmission system suitable for incorporation into the existing Newton-Raphson algorithm. Mathematical descriptions for two configurations, point-to-point HVDC and back-to-back HVDC are derived. Different reactive compensation control modes at AC terminals of HVDC are also considered in detail. The proposed model is implemented by a C programming language conformed to the standard of the common gateway interface (CGI). Users enter the raw datas of a power system, configurations, control objectives, parameters and reactive compensation modes of HVDC via interactive Web pages. The power flow calculation is performed in the information server and the results are returned to the user by a Web page. A Java-based graphical user interface is also provided to demonstrate the values of the maximal mismatch and control parameters at each iteration. A power flow calculation was performed on a small 9-bus test system to validate the proposed model and our web-based power flow solver. A practical large-scale power system was also simulated to demonstrate the performance of our power flow solver in various reactive compensation modes.