基于电流变化率的交流滤波器失谐元件在线辨识方法

Online Identification Method of Detuning Element of AC Filter Based on Current Change Rate

提出一种新颖的高压输电系统交流滤波器失谐元件在线辨识方法。将双调谐滤波器划分为三个部分,给出各个部分失谐元件辨识的原理,即通过基波电流变化率判断上段元件是否发生失谐,用两支路基波电流的比值来判断中段和下段元件是否失谐,并通过两支路基波电流的变化率来辨识中段的具体失谐元件,通过两支路相角差的变化来辨识下段的具体失谐元件。给出了实用的失谐元件在线辨识流程,以某高压直流输电工程实际安装的HP12/24滤波器为对象,通过仿真计算验证了提出方法的正确性和有效性,为实现交流滤波器失谐元件的在线辨识提供实用的方法。

This paper presents a novel method for on-line identification of the detuning component in AC filter in high voltage transmission system. The identification principle of detuning component in each part of a double-tuned filter which is divided into three parts is given, that is, the detuned element in upper part is identified by the fundamental current change rate, the element detuning is judged by the fundamental current ratio of the two branches in middle or lower segment of the filter element, and the concrete detuned element in middle section is identified by the change rates of the fundamental current in the two branches of this section, while that in lower section is identified by the change in the phase difference of the two branches in lower section. The practical application of the detuned element online identification method is presented, and the correctness and effectiveness of this method are verified by the simulation results on the basis of a HP12/24 filter of a practical HVDC transmission project. This paper provides a practical method to realize the on-line identification of the detuning element of passive AC filter.