一种抑制地铁列车牵引系统直流侧振荡的控制方法

A DC-Link Oscillation Control Method for Subway Train Traction System

为解决地铁列车牵引系统的直流侧振荡严重影响列车牵引性能的问题,文章以列车牵引系统的直流侧为研究对象,用可变功率负载等效牵引变流器和电机,建立了直流侧的非线性二阶系统模型。在分析该系统的平衡工作点后,用小信号分析法得到并分析了等效线性二阶系统,指出负载功率的增大是导致系统不稳定的原因,进而提出了状态反馈的控制方案,并通过根轨迹分析给出了能充分保证直流电压稳定的反馈增益的调整方法。最后,通过纯数字和半实物仿真验证了所提方法的正确性和有效性。

When DC link voltage of metro traction system is oscillating, performance of the metro vehicle is seriously deteriorated. In order to solve this problem, DC link of the metro traction system was studied, and the converter and the motor were equivalent to a power- variable load of DC link, and a nonlinear second-order model was obtained. After discussing the possible equilibrium operating points of the DC Link, a second-order linear model of DC link was derived by small signal analysis. Based on the stability analysis of the second- order linear model, it pointed out that increasing the load power would lead to instability and proposed a state feedback control to stabilize the system. By analyzing the root locus of the control system, it deduced the rule of adjusting the state feedback gain which can fully guarantee the stability of DC link. Numerical simulation and HIL simulation proved the correctness and validity of the proposed control method.