摘要
传统同步电源被电力电子并网变流器大量替代导致新能源电网无功裕度不足、静态电压稳定性降低,并网点电压失稳甚至崩溃的现象愈发明显。针对上述问题,本文以光伏发电系统为例,研究其采用新能源同步机(motor-generatorpair,MGP)的并网方式对系统静态电压稳定性的提升作用。首先介绍了MGP系统的原理并分析其功率传输特性;然后,基于能够反映节点电压和潮流关系的V-Q和P-V曲线法从理论上揭示了MGP系统能够增加无功裕度以提高静态电压稳定性;最后,在PSCAD/EMTDC软件中分别建立了光伏直接带负载和经MGP带负载的电磁暂态仿真模型,通过在相似的网络结构下设置不同典型功率因数的负荷变化,结合V-Q/P-V的响应特性对比得出两类系统的失稳电压、无功/电压裕度和电压降落等典型指标。结果表明光伏采用MGP系统并网后,系统的静态电压稳定性得到了显著提升。
The traditional synchronous power supply has been replaced by a large numbers of power electronic based grid-connected converters,resulting in insufficient reactive power margin of new energy power grid,reduced static voltage stability,and more and more obvious voltage instability or even collapse at the grid-connected point.Aiming at the above problems,the photovoltaic power generation system is used as an example in this paper to study the improvement of the static voltage stability of the system by using the new energy synchronous machine(motor-generator pair,MGP)grid-connected method.Firstly,the principle of MGP system is introduced and its power transmission characteristics are analyzed.Then,based on the V-Q and P-V curve methods that can reflect the relationship between node voltage and power flow,it is theoretically revealed that MGP can increase the reactive power margin to improve the static voltage stability.Finally,the electromagnetic transient simulation models of photovoltaic with load directly and via MGP were established respectively in the PDCSA/EMTDC software.By setting the load variation of different typical power factors with the similar system structure and combining with the V-Q/P-V response characteristics comparison,such typical indicators as unstable voltage,reactive power/voltage margin and voltage drop of the two systems are obtained.The results show that the static voltage stability of the original system can be significantly improved after the photovoltaic is integrated to the grid via MGP.
作者
邓宏远
黄永章
王哲凡
钟威凯
李晨阳
赵海森
DENG Hongyuan;HUANG Yongzhang;WANG Zhefan;ZHONG Weikai;LI Chenyang;ZHAO Haisen(School of Electrical and Electronic Engineering,North China Electric Power University,Beijing 102206,China;NCEPU(Yantai)Power Semiconductor Technology Research Institute Co.,Ltd.,Shandong Yantai 264006,China)
出处
《电力电容器与无功补偿》
2024年第2期117-125,共9页
Power Capacitor & Reactive Power Compensation
基金
国家自然科学基金项目(52177041)。
