牵引网谐振特性与治理方案

Harmonic Resonance Characteristics of Traction Network and Treatment Scheme

为研究牵引网谐波特性与治理方案,运用模态分析法计算牵引网网络节点导纳矩阵的特征根,分析电力机车在牵引网不同位置时系统的谐波谐振特性,并提出谐波治理措施。首先通过建立牵引供电系统等效电路及数学模型,分别计算牵引网在无滤波器、只安装阻波高通滤波器、安装阻波高通滤波器和单调谐滤波器3种情况下,机车负荷在不同位置时牵引供电系统模态阻抗,分析其谐振特性,并选取合适滤波器参数;最后根据实际线路参数,对3种情况下牵引网的谐波特性进行仿真验证。研究结果表明,牵引网谐振特性与牵引网本身属性有关,而与机车位置无关;阻波高通滤波器可以有效抑制交直交机车引起的高次谐波谐振,但会使低次谐波含量上升;继续投入合适参数的单调谐滤波器,可较好滤除交直机车产生的低次谐波,且不影响高次谐振抑制效果。

In order to research harmonic characteristics of traction network and their treatment, the eigenvalues of node admittance matrix of traction power supply systems are calculated using modal analysis, then the harmonic resonance characteristics of the system are analyzed for different positions of locomotive, and harmonic control measures are proposed. Firstly, a equivalent circuit and a mathematical model of the traction power supply system are established, the modal impedance of the system is calculated for different positions of locomotive in three cases: without filter, with only wave-trap high-pass filter, and with wave-trap high-pass filter and single tuned filter, and appropriate filter parameters are selected. Results show that, resonant frequency of traction network is related to line characteristics, independent of locomotive position;and the wave-trap high-pass filter can effectively suppress the harmonic resonance caused by AC-DC-AC locomotives, but it will cause rise of low-order harmonics. By switching on a single-tuned filter with appropriate parameters, it can filter low-order harmonics caused by AC-DC locomotives without affecting harmonic suppression effect.