摘要
接入电网的新能源故障低电压穿越稳态期间不合适的有功电流和无功电流注入会导致系统失稳,引发静态电压稳定问题。该文将正常稳态下的静态电压稳定分析方法扩展应用于新能源低电压穿越期间,分析其机理,定义短路故障的静态电压稳定指标。首先在考虑新能源低电压穿越控制策略下,得到单新能源接入电网低电压穿越期间电压解存在的临界电流值,定义短路故障稳态期间的低电压穿越静态电压稳定裕度指标(low-voltage ride-through static voltage stability margin index,LTSVSMI)。对比新能源低电压穿越期间和正常稳态的静态稳定特性的不同,两种稳定极限也存在明显差异;其次,为计算不对称故障下单新能源接入电网的稳定指标,将负序和零序网络作为故障附加阻抗接入故障点,分析不对称故障的影响;在多新能源电网中对故障端口按照对称故障和不对称故障进行特殊处理,并将其他新能源的影响纳入虚拟阻抗中,实现方法在多新能源接入电网中的应用;最后,以IEEE33节点配电网为例进行单新能源场站并网系统、多新能源场站并网系统仿真,验证方法正确性。
During the steady-state period of low-voltage ride-through in renewable energy integrated power grid with faults,inappropriate active and reactive current injections can lead to system instability,causing static voltage stability issues.This paper extends the normal steady-state static voltage stability analysis method to the low-voltage ride-through period of new energy generator,analyzes its mechanism,and defines the static stability index for short circuit faults.Firstly,considering the low-voltage ride-through control strategy of the renewable energy generator,the critical current value for voltage stability during the low-voltage ride-through period of a single renewable energy source integrated power grid is obtained.A low-voltage ride-through static voltage stability margin index(LTSVSMI)is defined.Difference is compared in static stability characteristics between new energy generators during low-voltage ride-through period and in the normal steady state,and there are significant differences between the two stability limits.Secondly,to calculate the stability index for an asymmetric fault in a single renewable energy integrated power grid,the negative-sequence and zero-sequence networks are treated as additional impedances connected to the fault point,and the impact of asymmetric faults is analyzed.In a multi-source renewable energy power grid,the fault ports are specially treated according to symmetric and asymmetric fault types,and the influence of other renewable energy sources is incorporated into virtual impedances,extending the application of the method to multi-source renewable energy integrated power grids.Finally,a single renewable energy source grid-connected system and a multi-source renewable energy grid-connected system are simulated based on the IEEE 33-node distribution network to validate the correctness of the derived results.
作者
谢德兴
肖仕武
XIE Dexing;XIAO Shiwu(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
北大核心
2025年第17期6777-6789,I0014,共14页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国网冀北电力公司科技项目(SGTYHT/23-JS-001)。
关键词
新能源电力系统
低电压穿越
静态电压稳定性
renewable energy power system
low-voltage ride-through
static voltage stability
作者简介
谢德兴(2000),男,硕士研究生,研究方向为新能源电力系统故障分析,1319226076@qq.com;通信作者:肖仕武(1974),男,副教授,研究方向为新能源电力系统故障分析与继电保护、电力系统分析与控制,xsw@ncepu.edu.cn。
