Modeling and simulation of DC rail traction systems for energy saving

Abstract

The modeling and simulation of the electrified transit system is an essential element in the design process of a new railway, or an existing one being modernized, particularly in DC powered railway systems which have significant losses in the power network. With the continuing focus on environmental concerns and rising energy prices, energy-saving operation technology for railway systems has been paid more and more attention. Previous work on energy optimization techniques mainly focuses on optimizing driving strategies subject to geographic and physical constraints, and kinematic equations, which only minimizes the mechanical energy consumption without considering the loss from the power supply network. This paper proposes a DC power network modeling technique and extends the traditional energy-saving methods to develop a novel approach which combines traction power supply network calculations and numerical algorithms to minimize the electrical energy delivered from substations. As train resistance is time-varying with the train movement, iterative algorithms are presented in order to calculate the energy consumption dynamically. Some case studies based on the Beijing Yizhuang Subway Line are presented to illustrate the proposed approach for power network simulation and energy-saving, in which the energy consumption of both the practical operation and optimal operation are compared.

Comprehensive approach to modeling dynamic processes in the system of underground rail electric traction

“…Methods of mathematical modeling make it possible to overcome these drawbacks. Modeling methods can be implemented by using structural linearized models [10], models applying equations of state variables [11], or by employing the nonlinear energy units, as, for example, units from the library SimPowerSystems in the programming environment Matlab/Simulink [12].…”

A New Mathematical Model of Dynamic Processes in Direct Current Traction Power Supply System

“…Now there is a great number of methods of diminishment of losses of electric power in the contact network [2], [3]. In the present paper the diminishment of losses of electric power and increase of power efficiency of the systems of electric supply will be attained due to introduction of new dynamic models describing the behavior of current and voltage in these networks.…”

“…At present, an approach based on the analysis of signals produced by the system is widely used to study the properties of complex systems, including experimental studies. This is very important in cases when it is practically impossible to describe the pro-cess under study mathematically, but we have at our disposal certain observable quantities, which allow to build a wanted model [3].…”

A new hybrid simulation integrating transient-state and steady-state models for the analysis of reversible DC traction power systems

“…Steady-state simulations do not depend on specific software environment, and no control loops are required in the model. Moreover, the time step of steadystate simulations is relatively long, typically Ts = 1 s [38][39][40]. Steady-state simulations provide a global overview of the system during a whole day with short computational time [20].…”