Nonlinear Second-Order Model and Equilibrium Point Characteristic Analysis of DC Traction Power Supply System

Abstract

According to the different features of the DC traction network transient current in the Metro, the electromagnetic transient process of traction power supply system that should be divided into the two forms of short-circuit fault and the low-frequency oscillation was proposed. While traction network short-circuit fault happens, the system model is a weakly nonlinear first-order differential equation, which feeder current is increasing exponentially and eventually stabilized. While the load current becomes low-frequency oscillation current, the system model is a nonlinear second-order differential equation. After linear processing in unique equilibrium point neighborhood, the state space equation of linear system is built, and the structural reason of low-frequency oscillation is revealed by eigenvalue analysis method. The simulation result shows that the simulation current waveforms are consistent with the recorded current waveforms and the division of transient process is reasonable.

Stability and Controllability of Nonlinear Systems

“…The stability of nonlinear systems has been studied by several authors including [1,8,9,10,11] and [12]. For example, in [10]; Li et al [10] studied nonlinear second order model and equilibrium point characteristic analysis of DC traction power supply establishing results in electromagnetic transient process of traction power supply system using eigen-value analysis method.…”

“…The stability of nonlinear systems has been studied by several authors including [1,8,9,10,11] and [12]. For example, in [10]; Li et al [10] studied nonlinear second order model and equilibrium point characteristic analysis of DC traction power supply establishing results in electromagnetic transient process of traction power supply system using eigen-value analysis method. In [11]; Okumus and Soykan [11] investigated the nature of the solutions of second order nonlinear difference equations establishing results on local stability of the equilibrium point and oscillatory behaviour of the systems using Linearization and Jacobian matrix method where they ensured that none of the eigen-values has modulus greater than one.…”

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

“…It is clear that such procedure leads to a very approximate model of the direct current traction power supply system (see, for example, [17]). Therefore, in this paper we propose another modeling method based on recurrence analysis.…”

“…It should be said that we do not know publications in which the direct current traction power supply system was modeled only by measuring currents and voltages (see [16,17]). The fact is that a large number of electrical elements forming such system practically exclude the possibility of constructing a detailed model through the combination of the equations of its individual elements.…”

Design and Health Evaluation of Monitoring Test Platform for Metro Traction Power Supply System

“…e literature pointed out that if the power of the locomotive is the same, the current and the traction network voltage are inversely proportional, so if the voltage of the catenary increases, the traction current must also decrease. So this article can draw a conclusion that the traction current under the DC supply voltage must be greater than the current under the DC supply voltage [4][5][6][7]. e faults of the subway traction power supply system can be divided into two major parts, including abnormal operating conditions and various short-circuit faults.…”