More Intelligent DC Railway Electrical Power Systems with Traction Power Control

Abstract

The load of a dc railway has very large peaks, while the average power is low. This makes the capacity of wayside power equipments larger. Recently the ratio of peak power to average power is even higher because of the introduction of a large number of electric multiple units with regenerative brake system. Such introduction has also made the contact system's unreceptiveness of the regenerated energy a significant problem. To solve these problems, researchers are trying to add intelligence to the power system.
In this paper, the authors describe a novel method of intelligently controlling traction power of trains. In this system the trains reduce their accelerating power to cut current peaks in wayside substations. With the proposed method we can reduce load peaks by up to 31%, which means that the characteristics of railway load has been changed drastically. The delays of the trains involved are negligible. Also the unreceptiveness of the regenerated power can be almost eliminated.
In the first part of this paper, we describe the idea of traction power control. Then we describe how the idea is applied to wayside substation load peak suppression or receptiveness improvement, with some simulation results to prove the method. Finally, we discuss the possibility of further improvement of the system by adding communication capability between trains and wayside equipments.