摘要
光伏电站通过构网型柔性直流输电系统传输功率时存在引发振荡的风险。现有小信号稳定性分析方法通常忽略光伏电站内部各机组间的动态差异以简化计算,然而在实际运行中,由于光伏机组输出有功功率或控制参数存在差异,这种简化可能导致分析结果出现误差。为此,针对次同步频段下光伏机组锁相环主导振荡特性,研究了光伏机组输出有功功率及锁相环控制参数差异对系统小信号稳定性的影响。研究发现,光伏机组输出有功功率和锁相环控制参数的差异会改变复平面上主导振荡模式的位置,而系统稳定边界仅由电站内所有机组对应参数的最小值与最大值决定。基于此,提出了一种区间估计方法,可预测不同输出有功功率或控制参数下主导振荡模式的分布范围,从而在考虑光伏机组动态差异的情况下实现了系统小信号稳定性的快速评估,为实际系统的振荡预警提供了参考。仿真结果验证了所提方法的正确性和有效性。
The photovoltaic(PV)power station connected to the voltage source converter-based high voltage direct current(VSC-HVDC)system not only transmits power but also introduces the risk of oscillations.The existing small-signal stability(SSS)analysis methods typically simplify computational complexity by neglecting the dynamic differences between individual PV units in PV power stations.However,in practical systems,there are differences in active power output or control parameters of PV units,which may lead to errors in small-signal stability analysis results.Therefore,the impact of differences in active power output or phase-locked loop(PLL)control parameters of PV units,which are PLL-dominated,on SSS of the system is analyzed in the sub-synchronous frequency range.The results show that the differences in active power output or PLL control parameters of PV units may affect the position of dominant oscillation mode in complex plane,while the stability boundary is determined solely by the minimum and maximum values of corresponding parameters of all PV units.Therefore,an interval estimation method is proposed to predict the range of dominant oscillation modes of PV units under different active power outputs or control parameters,which enables rapid SSS assessment while considering the dynamic differences of PV units,and provides a reference for oscillation warning in practical systems.Finally,the effectiveness of the proposed method is validated through simulation examples.
作者
韩翔宇
HAN Xiangyu(State Grid Chengdu Electric Power Supply Company,Chengdu 610041,Sichuan,China)
出处
《四川电力技术》
2025年第5期23-31,39,共10页
Sichuan Electric Power Technology
基金
国家自然科学基金项目(62403340)。
关键词
光伏电站
柔性直流输电
小信号稳定性
区间估计
photovoltaic power station
VSC-HVDC
small-signal stability
interval estimation
