Topology optimization strategy of flexible interconnected lowvoltage distribution network based on mathematical analysis

The traditional distribution network structure is solidified and lacks flexibility, which is difficult to adapt to the new situation of large-scale access of distributed energy and rapid growth of electric load.This study proposes a topology optimization strategy for flexible interconnected low-voltage distribution network based on BTB-VSC, and constructs a mathematical model of distribution network with embedded DC and a VSC converter control system.In the methodology, a two-level voltage source converter is used to realize flexible interconnection between feeders, AC circuit equations and DC circuit equations are established, voltage deviation control and voltage sag control strategies are designed, and BTB-VSC optimization algorithm is developed for topology identification.The feasibility of the algorithm is verified by a 12-node network model and simulated in a large distribution network with 120 users connected to 4 stations.The results show that in a Gaussian noise environment with a signal-to-noise ratio of 20 dB, the BTB-VSC optimization algorithm reduces the number of time sampling points required to achieve 100% accuracy in topology identification from 235 to 200, which provides higher identification accuracy and faster convergence speed than the PCA algorithm.The strategy effectively solves the distribution feeder load imbalance problem, improves the terminal voltage quality, enhances the power supply reliability of the distribution network, and provides technical support for the friendly grid-connection of distributed power sources and the intelligent development of the distribution network.