宽邦工程投运后高岭直流送端系统电压稳定分析

Voltage Stability Analysis of Gaoling DC Transmitting System After Operation of Kuanbang Project

宽邦工程投运前,高岭背靠背直流(以下简称高岭直流)送端系统存在电压支撑能力不足、交流线路故障后直流闭锁问题。宽邦工程投运后,高岭直流增加了一条至东北电网主网的交流通道。直流及其配套工程的安全稳定分析中常用潮流分析、短路比分析、暂态稳定分析等方法,本文在此基础上增加了静态电压稳定分析,最后针对高岭直流送端近区交流线路故障后的电压稳定问题提出了预控直流功率和利用稳控装置回降直流功率的控制策略,该策略可提升高岭直流稳定水平并已应用于实际运行。本文所应用的分析方法和控制策略在直流系统及其配套工程稳定分析中具有一定的适用性。

Before the operation of the Kuanbang project,the Gaoling back-to-back DC(here in after re-ferred to as the Gaoling DC)transmitting system has such problem as insufficient voltage support capability and DC blocking after the fault of AC line.After operation of Kuangang project,a channel to the truck of northeast grid is added from Gaoling DC.Power flow analysis,short-circuit ratio analysis,transient stability analysis,etc.are commonly used in the stability analysis of DC and its supporting projects.In this paper,static voltage stability analysis based on the forward analysis is added.Finally,the control strategies of pre-control DC power and returning DC power by the stability control device are proposed for the voltage stability problem after the fault of the near-area AC system in the Gaoling DC transmission terminal.This strategy can improve the stability of Gaoling DC and has been applied for actual operation.The analysis method and control strategy used in this paper have a definite applicability in the stability analysis of DC system and its accessory project.