A Passive Calculation Method for Loop-Closing Current in Distribution Networks Based on Thevenin Theorem

In the operation and planning of active distribution networks, loop-closing operations involve complex current calculations. To avoid introducing additional disturbances to the power system, this paper proposes a passive calculation method for loop-closing current in distribution networks based on Thevenin theorem. Initially, through the system's inherent small disturbances and applying Thevenin theorem, the equivalent impedance and open-circuit voltage of the distribution network are calculated. This process simplifies the complex distribution network into a single-port network model consisting of an independent voltage source in series with an impedance. Subsequently, using this equivalent model and the open-circuit voltages and equivalent impedance at the loop-closing points, the loop-closing current is calculated. Finally, the accuracy of the equivalent impedance and open-circuit voltage calculations is validated through comparisons of different disturbance methods. Loop-closing currents are then computed for various distribution network scenarios, demonstrating that this method, which does not require additional disturbance testing, can accurately calculate loop-closing currents while ensuring system stability. This provides reliable technical support for the safe operation of distribution networks.