适用于单调谐滤波器的失谐元件在线辨识方法

进行滤波器失谐元件的在线辨识对于提高高压直流输电系统的运行可靠性具有重要实用价值。提出了一种新颖的高压直流输电系统直流侧单调谐滤波器失谐元件的在线辨识方法。该方法通过测量流过滤波器的电流并进行谐波分析,通过对滤波器谐振频率下谐波电流的变化来判断滤波器是否发生失谐。在发生失谐的情况下,计算特定频率处谐波电流变化率的比值,即可辨识出具体的失谐元件及失谐度。该方法计算简单,仅需对原有滤波器进行简单改造即可实现,扩展了滤波器的功能。给出了该方案的原理,并对其应用于辨识不同滤波器的失谐元件进行了仿真计算,结果验证了所提出方法的正确性和有效性。

Online identification method of detuning element of single-tuned filter

The online identification of the filter detuning elements has an important practical value for improving the reliability of the HVDC system. This paper presents a novel method for online identification of the detuning elements of the DC-side filter of the HVDC system. The method only needs to measure and extract the harmonic components from the current that through the single-tuned filter. Weather the filter has detuned or not can be known by the analyzing the change rate of the harmonic current under resonant frequency. In the situations that the filter has detuned, the detuned elements can be identified by calculating the ratio of the change rates of several special harmonic current. This method can be realized based on a simple modification of the traditional DC-filter, and thus the function of the filter is expanded. This paper presents the principles of the proposed method and the simulation results of the application of this method on different filters verify the validity and effectiveness of the proposed method.