Simulating on-line dynamic voltages of multiple trains under real operating conditions for AC railways

The analysis of railway power supplies (RPS) presents a unique type of load flow problem which is characterized by its constant moving loads, dynamically changing load types (constant current/constant power), and its specialized network structure. When multiple trains and the capacitors for power factor correction are also involved, the analysis of this special kind of power system can be very complicated and time consuming which will prevent on-line state analysis from becoming possible. This paper presents a novel and extremely efficient algorithm to solve this special kind of power flow problem with high precision. By first decoupling the autotransformer (AT) current into 2 equal phasor components and then applying an iteration-based circuit-analysis approach, the RPS power flow problem can be solved in an accurate but extremely efficient manner. An on-line railway power-supply state analyzer (RPSA) based on this approach is presented in this paper while the extension of using this approach to perform power factor corrector (PFC) simulation is also presented.