Large-Signal Stability Analysis of Low-Voltage Power Distribution System Considering Random Disturbance Intensity

The low-voltage power distribution system (LVPDS) may experience large-signal instability issues due to random power disturbances from distributed renewable energy sources and constant power loads. Firstly, a small-signal model of the LVPDS is established, which can be used to analyze changes in eigenvalues under different load powers. Secondly, a large-signal model of the LVPDS considering random disturbances is established using the Takagi-Sugeno modeling method. This large-signal model can be used to effectively evaluate changes in the largest estimated domain of attraction under different intensities of random disturbances. By comparing the eigenvalue trajectories and the largest estimated domains of attraction under different random disturbance intensities, an applicability criterion for small-signal models based on the maximum random disturbance intensity is proposed. Additionally, a method for solving the maximum random disturbance intensity based on the largest estimated domain of attraction is presented in this paper. Finally, the switching models of the LVPDS are constructed using PLECS software and the RT-box hardware-in-the-loop (HIL) experimental platform, respectively. The validity of the constructed models and the proposed criterion is verified by multiple sets of simulation and experimental waveforms.