高速列车dq阻抗测量方法及其装置设计

dq Impedance Measurement Method and Its Device Design of High-speed Train

高速铁路供电系统常因高速列车和牵引供电网的"阻抗"特性不匹配,出现一系列宽频带振荡和不稳定问题。精确评估二者的阻抗特性是解决此类问题的重要手段。目前牵引供电网阻抗的获取技术已较为成熟,而高速列车阻抗的评估方法尚有不足,且缺乏相应的装置。该文首先基于电压扰动串联注入的方式,提出一种新型的高速列车dq阻抗测量方法。该方法通过Hilbert变换和非对称Park变换获取dq坐标系下的响应电压、电流信号,进而计算高速列车的dq阻抗特性。然后相继提出一种基于模块化多电平变流器(modular multilevel converter,MMC)结构的阻抗测量装置总体设计方案,给出电压扰动单元主电路的设计及其控制方法。最后,利用MATLAB/SIMULINK仿真验证所提基于非对称Park变换的高速列车dq阻抗测量方法及其装置设计的有效性。相比传统的单相系统dq阻抗测量方法,该方法无需重新设计扰动,有效减少扰动注入的次数,简化扰动设计和测量过程,且该装置设计方案可为开发高速列车阻抗测量装置提供重要参考。

Broadband oscillation and instability problems often occur in high-speed railway system since the impedance mismatch between high-speed trains and traction power supply network. Thus, it is important to evaluate their impedances for solving such problems. To date, the impedance measurement technology for the traction power supply network is relatively mature, but for the high-speed train, it is defective and device-less. In this paper, a novel method of dq impedance measurement for high-speed train was proposed based on voltage disturbance injection in series, which can obtain the response voltage and current in the dq frame with Hilbert transformation and asymmetric Park transformation to calculate the dq impedance characteristics of high-speed train. Then the device design based on modular multilevel converter(MMC) structure was presented, as well as the main circuit and its control method of the voltage disturbance unit. Finally, MATLAB/SIMULINK simulation verified the effectiveness of the proposed method and measurement device. Compared with the traditional dq impedance measurement method for single-phase system, the proposed method without redesigning disturbance can reduce the times of disturbance injection effectively, which simplifies the disturbance design and measurement process. Moreover, the designed device can provide an important reference for developing the impedance measurement device for high-speed train.