背靠背直流输电系统的QPC功能策略优化  

Optimization of QPC Function Strategy for Back to Back HVDC System

作　　者：叶晌骏 薛海平[1] 张庆武[1] 杨鹏 张长权 常勇 YE Shangjun;XUE Haiping;ZHANG Qingwu;YANG Peng;ZHANG Changquan;CHANG Yong(NR ElectricCo.,Ltd.,Nanjing 211102,China;China Electric Power Equipment and Technology Co.,Ltd.,Beijing 100052,China)

机构地区：[1]南京南瑞继保电气有限公司,江苏南京211100 [2]中国电力技术装备有限公司,北京100052

出　　处：《电工技术》2021年第5期109-114,共6页Electric Engineering

摘　　要：直流输电系统低功率运行时,换流器消耗的无功小于交流滤波器提供的无功。直流低负荷无功控制QPC通过调大触发角或熄弧角来增大换流器的无功消耗,抑制无功过剩,但整流侧因分接开关过应力的限制,常使换流器消耗过剩,无功能力受限。利用背靠背直流工程无直流线路、直流电压无需严格控制的特点,对QPC功能策略进行了优化,通过降低直流电压,增大整流侧QPC功能的调节范围。在RTDS实时数字仿真平台上基于实际直流工程模型进行验证,结果表明优化后的QPC功能策略能有效增大整流侧无功调节范围,从而改善整流侧无功过剩对交流系统的影响。When the HVDC system is in low power operation,the reactive power consumed by the converters is less than the reactive power provided by the AC filters.The DC low-load reactive power control QPC increases the reactive power consumption of the converter by increasing the trigger angle or arc extinguishing angle,and suppresses excess reactive power.However,due to the over-stress restriction of the tap changer on the rectifier side,the converter often consumes excessively and has no functional limitation.Utilizing the characteristics of back-to-back DC projects that there is no need to strictly control the voltage of the DC line,the QPC function strategy is optimized.By reducing the DC voltage,the adjustment range of the QPC function on the rectifier side is increased.It is verified on the RTDS real-time digital simulation platform based on the actual DC engineering model.The results show that the optimized QPC function strategy can effectively increase the reactive power adjustment range of the rectifier side,thereby improving the impact of excess reactive power on the rectifier side on the AC system.

关 键 词：直流输电系统 换流器 背靠背直流 QPC功能 无功控制 

分 类 号：TM721.1[电气工程—电力系统及自动化]