Discrete Wavelet Transform based Transient Voltage Vulnerable Node Assessment for Renewable Energy Integrated Power System

Due to the transformation of the essential characteristic, the power system voltage issue in China shifts sharply from the static optimization to transient stability assessment and control problems with regard to predefined faults. That is attributable to the large-scale renewable energy integrated into power systems, together with long distance inter-area transmission and consumption. Amongst these problems, the fundamental process is to select the vulnerable nodes for sake of post-fault transient voltage. The well-known practical assessment index for transient voltage utilizes the long-period integral value of the post-fault transient voltage dip and recovery curves, which is originally designed for the traditional power system, In this paper, a novel multi-resolution analysis (MRA) method is proposed for renewable energy involved power system transient voltage disturbed curves decomposing, using the discrete wavelet transform (DWT) analysis. Furthermore, a new post-fault transient voltage vulnerable node screening method is proposed based on these decomposition coefficients. A 50% photovoltaic (PV) source integrated power system (36-bus model) is adopted for the proposed method validation.