高压直流输电系统直流滤波器的设计

直流滤波器是抑制高压直流输电(HVDC)直流侧谐波的最有效、最典型且应用最广泛的设施,其设计的优劣既牵涉到HVDC系统的运行性能和安全稳定性,又关系到整个系统总投资的高低。为深入研究直流滤波器的设计,首先总结了现有HVDC工程直流滤波器的配置现状,在分析直流滤波器电路结构和阻抗-频率特性的基础上,忽略电阻的影响,根据调谐点滤波器阻抗Z=0,推导了双调谐滤波器和三调谐滤波器设计的精确公式,提出了详细的参数设计方法,而公式有多组解,选取最大的串联谐振频率rω1那一组解,此时滤波器阻抗-频率特性在谐振点附近的曲线比较平坦,滤波效果最好。然后以HVDC实际工程直流滤波器参数进行验证,结果表明所提出的公式完全正确,可为直流滤波器的参数设计提供工程指导。最后以满足等效干扰电流为基本要求,对某HVDC工程的直流滤波器进行了实例设计。

Design of DC Filters in HVDC Transmission System

A perfect scheme about DC filters can not only improve the operation performances but also reduce the total costs of high voltage direct current transmission systems.Firstly,the configuration of DC filters of high voltage direct current transmission projects in China is summarized.Based on the analysis of circuits and impedance-frequency characteristics of DC filters and the impedance being equal to zero at tuning point,two precision formulas on parameters designs for double-tuned filters(DTF) and triple-tuned filters(TTF) are presented.It is verified that selecting the solution of the highest series resonance frequency from several solutions of formulas has an optimum filtering effects.Two examples of parameters designs for double-tuned filters and triple-tuned filters in a HVDC transmission project are calculated based on the two formulas.The comparison of the calculation results with the real project parameters of DC filters shows that the two formulas put forward in this paper are correct.At last,a parameter design for DC filters in a certain high voltage direct current transmission project is given to satisfy the requirements of equivalent disturbing current.The formulas will be helpful to designing the DC filters of high voltage direct current transmission projects.