基于宽频带扰动的牵引供电系统频域阻抗测量方法

Frequency-domain impedance measurement method for traction power supply system based on broadband perturbation

当不能准确获取牵引供电系统详细的拓扑及参数时,很难对其频域阻抗特性进行量化计算与分析。为得到精确的牵引供电系统频域阻抗特性,提出了一种基于宽频带扰动的牵引供电系统频域阻抗精确测量方法。介绍了牵引供电系统频域阻抗测量原理;基于正弦脉宽调制(SPWM)机理,结合能量谱分析,提出了一种只需一次实验即能得到牵引供电系统测量点处精确频域阻抗特性的测量方法;通过软件仿真和实物实验分别对所建牵引供电系统模型进行频域阻抗测量,结果表明阻抗测量值均能够与理论值保持一致,共同验证了所提阻抗测量方法的正确性与实用性。

It is difficult to quantify the frequency-domain impedance of the traction power supply system when the accurate topology and parameters are unavailable. To obtain accurate frequency-domain impedance characteristics of traction power supply system,a broadband perturbation-based impedance measurement method is presented. The impedance measurement principles of traction power supply system and calculation formula are introduced. Based on the SPWM( Sinusoidal Pulse Width Modulation) mechanism and the energy spectrum analysis,a disturbance method is proposed to obtain the accurate frequency domain impedance characteristics at the measuring points of the traction power supply system through only one perturbation experiment. The impedance of traction power supply system is obtained using both software simulation and physical experiment. Test results show that the measurement values are consistent with theoretical values,which verifies the effectiveness of the proposed method.