单相顺序延时选相合闸方式抑制500 kV过补偿线路直流偏置的仿真研究

随着电力系统容量的增加,线路的缩短,基于无功补偿而保留并联电抗器的现象越来越多,如何避免高补偿带来的直流偏置可能造成的系统故障成为一个需要研究的问题。首先基于补偿线路发生直流偏置的机理进行分析,得到了影响线路直流偏置的影响因素。然后基于ATP/EMTP电磁暂态仿真软件建立了仿真模型,并通过仿真计算与500 kV线路试验结果的对比校验了仿真模型的有效性。通过各影响因素的仿真研究,得到不同影响因素的交叉影响特性。通过对采用相控合闸方式的可行性研究,提出了采用单相顺序延时选相合闸方式抑制线路直流偏置的优势。

Research on the depression of DC offset of overcompensated transmission lines by single-phase sequential switching technology

With the increase of power system capacity and the shortening of circuit lines, more and more parallel reactors are retained for reactive power compensation. How to avoid the power system fault caused by DC offset due to high compensation is becoming a problem need to be studied. Firstly, based on the analysis of the mechanism of DC offset in compensating circuit, the influencing factors of DC offset are obtained. And electromagnetic transient simulation model is established based on ATP/EMTP. And the validity of simulation model is made by comparison of the simulation and 500 kV line test results. Cross impact characteristics of the different influence factors is got through the simulation research. And after the feasibility study of the phase selection closing, the advantage of the sequential time-delay phase closing method is put forward for the suppression of DC offset. This work is supported by Science and Technology Program Self-financing Fund of Hebei Province (No. 17212116) and Science and Technology Program of State Grid Corporation of China.