基于阻抗约束的铁路电力牵引变流器稳定性控制

Stability Control of Railway Electric Traction Converters Based on Impedance Constraints

在铁路电力牵引供电系统中,dq阻抗是衡量系统稳定性的重要参数。若无法将dq阻抗控制在合理范围内,则会导致不稳定、低效或低质量的电力传输,为此,提出铁路电力牵引变流器稳定性自动控制技术。基于四象限变流器的能量转换分析结果测量阻抗,获取变流器的dq阻抗测量值,引入Hilbert变换法将其转换为响应信号作为自适应自抗扰比例积分控制器的输入信号,建立阻抗阈值,将dq阻抗控制在设定的阈值内,对低频振荡现象展开控制。结果证明,所提方法处理低频振荡现象时响应速度快、抑制效率高,能够实现对铁路电力牵引变流器稳定性的自动控制。

In the railway electric traction power supply system,dq impedance is the important parameters to measure system stability.If dq impedance cannot be controlled within a reasonable range,it will lead to unstable,inefficient or low-quality power transmission.Therefore,the automatic stability control technology of railway electric traction converter is proposed.Based on the energy conversion analysis results of the four quadrant converter,the impedance is measured,and the dq impedance measurement value of the converter is obtained.The Hilbert transform method is introduced to convert it into the response signal as the input signal of the adaptive active disturbance rejection proportional integral controller.The impedance threshold is established,and the dq impedance is controlled within the set threshold to control the low-frequency oscillation phenomenon.The results show that the proposed method has fast response speed and high suppression efficiency when dealing with low-frequency oscillation,and can realize the automatic control of the stability of railway electric traction converter.