±800kV云广直流输电工程平波电抗器参数选择和布置方案

Parameters Selection and Arrangement of Smoothing Reactors for ±800 kV Yunnan-Guangzhou UHVDC Transmission Project

为抑制直流输电系统扰动引起的直流电流上升速度,避免轻载时发生直流电流断续,以及降低直流侧谐波,需要在换流器直流侧出口装设平波电抗器。笔者根据±800 kV云广直流输电系统主回路结构,详细计算了平波电抗器的电感参数;特高压直流输电系统由于采用特殊的换流器联络结构,其平波电抗器布置不同于±500 kV超高压直流输电系统。文中搭建了基于PSCAD/EMTDC的云广特高压直流输电模型,从谐波特性、直流操作过电压等方面对3种平波电抗器布置方案进行了仿真对比研究,其结果对实际工程具有一定的指导意义。

To restrain the rising speed of fault current due to disturbance in UHVDC transmission system, avoid the discontinuity of direct current in light load condition, and reduce the harmonic at DC side, smoothing reactors are needed at the DC side outlet of the converter. On the basis of the main circuit structure of ±800 kV YunnanGuangzhou UHVDC Transmission System, the inductance values of the smoothing reactors are calculated in this paper. Because of the special connecting tructure of the converters of UHVDC system, the smoothing reactors arrangement is different from that of ±500 kV HVDC system. A simulation model of ±800 kV Yun-Guang UHVDC Transmission System based on PSCAD/EMTDC is built, and three arrangement schemes of smoothing reactors are compared in terms of harmonic characteristic and switching DC over-voltage via simulations.