特高压交流示范工程功率摆动机理分析  

Power swing mechanism analysis of UHV AC pilot project

作　　者：刘辉[1] 吴涛[1] 李群炬[1] 王丰[1] 沈宇[1] 刘平[1] 

机构地区：[1]华北电力科学研究院有限责任公司,北京100045

出　　处：《中国电力》2010年第7期9-13,共5页Electric Power

摘　　要：2008年底联络华北电网和华中电网的我国首个跨区域1 000 kV长治—南阳—荆门特高压交流试验示范工程投入运行。特高压投运后,华北电网和华中电网发生的几次跳机故障引起了特高压联络线传输功率的大幅度摆动,特别是第1摆出现了明显的超调,威胁到了特高压系统的安全运行,因此分析功率摆动的机理已成当务之急。利用跳机故障后PMU录波数据总结特高压潮流波动的基本规律。通过分析华北和华中电网特高压互联后出现的大区低频振荡模态,指出跳机后特高压潮流的波动实际是功率缺额再分配所引起的大区低频振荡,由于阻尼较强,波动很快收敛。用二阶系统阶跃响应理论推导出跳机后特高压有功潮流响应的数学表达式,并把第1摆幅度和稳态偏差的PMU录波值与计算值进行比较,表明理论计算的正确性和准确性。利用该方法可以估算跳机故障时特高压潮流的波动情况,计算出第1摆的幅度及预测跳机故障对特高压系统的影响。China＇s first cross-regional UHV AC pilot project of 1 000 kV, which made the interconnection between north China power grid and central China power grid by the line of Changzhi-Nanyang-Jingmen, had been put into operation at the end of 2008. After the commissioning, some tripping events occurred within the two grids and led to serious power swings on the UHV tie lines. Especially, the first-swing overshoot had made a threat against the security of the UHV system. Therefore, an analysis of its dynamic characteristics would be very critical. Data of the generator tripping events recorded by PMUs were analyzed to obtain some basic rules of UHV power flow. By the study of low-frequency oscillation mode arising from UHV interconnection, a conclusion was made that power flow fluctuations was due to the redistribution of the power shortage, and as the damping was strong, the fast convergence had been obtained. Mathematical models of the UHV power flow were derived by second-order system step response theory. The first swing recorded by PMUs and the steady state values by the calculation were compared. It is suggested that the theoretical calculation is correct and accurate. With the proposed method, the UHV power flow and first power swing can be obtained and utilized to predict the impacts of generator trippings on UHV systems.

关 键 词：特高压 功率摆动 低频振荡 二阶系统 阶跃响应 

分 类 号：TM712[电气工程—电力系统及自动化]