Electric load estimation techniques for high-speed railway (HSR) traction power systems

As modern (e.g., high-speed railway (HSR)) traction power systems (TPS) become more and more comparable in size to grid capacity, dynamic load estimation (DLE) has become not just an important tool for TPS planning, but also an indispensable tool for utility companies to evaluate traction system's accurate unbalance impact on the grid. Without a good DLE algorithm, unbalance impact can easily be underestimated and causes power system instabilities. A good DLE must be carried out with a power engineering perspective while incorporating real railway operating principles and practices. However, due to the lack of well-documented literature on this subject and the interdisciplinary nature of DLE, it usually presents a difficult task for the system planner. As such, this paper presents an accurate DLE algorithm capable of achieving these goals, while providing a complete coverage of all the principles and parameters used during the derivation. The methodology developed here is applicable to HSR TPS and to conventional railways as well with minor modifications. Unbalance impact evaluation of the new Taiwan HSR is presented in the last part of the paper, while further application of the proposed DLE algorithm is also proposed.