直流输电系统孤岛运行交流滤波器设备能力评估方法

Method for evaluating AC filter equipment capability of islanding operation in an HVDC transmission system

高压直流输电系统在孤岛运行方式下,若发生系统故障,交流系统频率会出现较大范围的变化,将增大交流滤波器元件的电流。通过对直流输电系统孤岛故障条件下频率变化的分析,研究了频率变化对交流滤波器元件额定电流的影响。基于单调谐滤波器的阻频特性,提出了多调谐滤波器频率波动条件下的定值计算方法。据此分析了交流系统条件和滤波器参数对设备定值随频率变化的影响,提出了在孤岛条件下交流滤波器设备能力的评估方法。通过与仿真结果的对比,验证了所提方法的有效性。

When an HVDC power transmission system is operating in isolated island mode,if a system failure occurs,the frequency of the AC system will change over a large range.This will increase the current of the AC filter element.In this paper,the influence of the frequency change on the rated current of the AC filter components is studied by analyzing the frequency change under the conditions of the island fault of the HVDC transmission project.Based on the characteristics of the frequency-supplied filter of a single-tuned filter,a method for calculating the settling value under multi-tuned filter frequency fluctuation is proposed.On this basis,the influence of the conditions of the AC system and the parameters of the filter on the fluctuation of the device setting with frequency fluctuation is analyzed.A method for evaluating the capabilities of AC filter equipment under island conditions is proposed.Simulation results verify the effectiveness of the proposed method.