摘要
针对变速风电机组控制环节间交互作用对系统稳定性影响,该文构建了由两个开环子系统组成的闭环互联系统模型。基于所构建模型,从开环模式谐振角度揭示含变速风电机组电力系统的振荡机理。当两个开环子系统对应的开环模式在复平面分布位置接近时将引发开环模式谐振,此时控制环节间将呈现强动态交互作用,使子系统开环模式对应的闭环特征根朝相反方向移动,其中一谐振特征根朝复平面虚轴方向移动,导致系统阻尼水平的降低。提出一种估计开环模式谐振条件下闭环特征根在复平面分布位置的方法,进而评估系统阻尼水平。此外,分析了变速风电机组与电网的连接强度、系统运行点对开环模式谐振的影响。最后,通过直驱和双馈风电系统仿真算例对所提分析方法和结论进行了验证。
A closed-loop interconnected model of a power system with variable speed wind generator was established to investigate the impact of dynamic interactions between converter control loops on system stability, wherein, the system was decomposed into two separate but interconnected openloop subsystems. Based on the established model, oscillations mechanism was revealed from the perspective of open-loop modal resonance（OLMR）. Under the condition of OLMR, i.e., two open-loop subsystem modes are close to each other on the complex plane, strong dynamic interactions between converter control loops are caused which will make the coupled modes repulse each other to move towards opposite directions. It is very likely that OLMR may lead one of the resonant modes to move along the imaginary axis, and degrade the system damping. An estimation method is proposed in this paper to predict the distribution positions of closed-loop resonant modes on the complex plane under the condition of OLMR, and thus estimate the damping degradation. In addition, the effects of the connection strength, operation points on OLMR are also analyzed. Finally, study cases of example power system with the permanent magnet synchronous generator（PMSG） or double fed induction generator（DFIG） are presented to demonstrate and evaluate the analysis and conclusions made.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第22期6481-6491,共11页
Proceedings of the CSEE
基金
国家重点研发计划项目(2016YFB0900602)~~
关键词
变速风电机组
开环模式谐振
动态交互
直驱型风电机组
双馈型风电机组
variable-speed wind generator
open-loop modal resonance（OLMR）
dynamic interaction
permanent magnet synchronous generator（PMSG）
double fed induction generator（DFIG）
