基于谐波电流变化率的高压直流输电系统直流侧滤波器参数的在线辨识

The Online Parameters Identification of the DC-Side Filter of High-Voltage Direct Current System Based on Harmonic Current Change Ratio

提出了一种新颖的高压直流侧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各个支路的电流并进行谐波分析,通过判断不同次数谐波电流的变化率辨识出具体的失谐元件。给出了该方法的原理和具体实现过程,推导了不同元件的失谐度与谐波电流变化率的理论表达式,以此为基础分别提出滤波器失谐、滤波器串联和并联部分失谐元件及失谐程度的判据。通过对单调谐和双调谐滤波器的仿真计算,验证了所提出方法和判据的正确性和有效性。该方法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。可实现直流滤波器失谐元件的在线准确、快速辨识,具有较好的实用价值。

This paper presents a novel method to online identify detuning components of the filter at the DC side in HVDC system. This method only needs to measure the current of each branch of the filter and analyzes the harmonic component, and then identifies the detuning component through calculating the change rates of several harmonic currents. The principle and the implementation of the proposed method are presented, and the theoretical formula is deduced about the relationship between the harmonic current change rate and the detuning ratio of different elements.. Thereafter, this paper proposes the criterions to identify the filter detuning, detuning components in series and in parallel of the filter, and the detuning degree. Simulation results of single-tuned and double-tuned filters show the correctness and effectiveness of the proposed method. This method can expand the original functions of the traditional filter with simple modification. It can realize the online identification of detuning components accurately and rapidly, and has good application prospect.