基于临界转变理论的电力系统电压稳定分析与预警

Research on Power Systems Voltage Stability Assessment and Prediction Based on Critical Transition

针对电力系统中面临的电压稳定问题,提出一种基于临界转变理论的电压失稳评估与预警方法。通过数学推导,证明了系统在接近电压失稳的过程中,系统的非线性度不断增强,系统变量由于随机扰动导致与稳态量的偏差离散度逐渐增大,外在表现为系统变量方差的单调增大。同时,推导出系统变量方差与驱动参数之间的标度律关系。实际应用时,利用实测数据对标度律进行简单的非线性拟合,即可快速估算出电压失稳点,为调度人员提供辅助决策信息。该文还分析所提方法与传统特征分析法的一致性。在2机3节点仿真系统中的仿真结果验证了提出方法的有效性。在没有详细系统模型或模型参数不准确时,常规基于模型的方法适用性有限。而该文提出的方法基于量测数据,能时刻跟踪系统当前状态,具有广阔的应用前景。

In order to address the long-term voltage instability problems in power systems, this paper proposed a voltage stability assessment and prediction method based on the critical transition theory. In this paper, it is proven rigorously that as the system approaches the collapse point, the system nonlinearity will dominate so that the variance of the deviation will increase dramatically. In addition, this paper has derived the relationship between the variance and the bifurcation parameter to make the collapse point forecasting possible. This paper has also found the consistency between the proposed method and the largely used eigen-analysis method. The simulation results on a two machines three buses and a ten machines thirty-nine buses power system model have verified the derivation. The method is totally based on measured data so that it is relatively quick and has the potential to be implemented in real world applications since the real power system model is unavailable or the parameter is inaccurate.