Voltage Stability Analysis Strategy for Wind Power Grid Connected Systems Based on Multi Binary Table Criteria

Accurately and quantitatively assessing the voltage stability margin of each node in a power system following a fault disturbance is crucial for ensuring the safe operation of the power grid. Currently, engineering experience criteria are commonly applied both domestically and internationally to address transient voltage instability in systems. These criteria generally evaluate whether the system voltage remains stable by examining the depth and duration of voltage drops at each bus post-disturbance. However, practical criteria are limited in their ability to quantify the voltage stability margin of individual nodes, allowing them only to determine if the voltage is in a stable state. The multi- binary table criterion offers a precise method to ascertain the transient voltage stability margin by quantifying the deviation depth and duration of state variables from a set threshold. This paper utilizes the low voltage ride-through curve of wind turbines to assess the transient voltage stability of wind power grid-connected busbars using the multi-binary table approach. By integrating voltage disturbance trajectories and applying the principle of curve integration, different weights are assigned to state variables based on their drop depths. The impact of varying drop levels on the system's transient voltage stability is evaluated through the area of the integration region. The degree of voltage drop varies according to different integration intervals.