An Integrated Sensitivity Calculation Method for Cross Voltage Levels of Unbalanced Medium- and Low-voltage Distribution Network

Voltage-power sensitivity reflects the relationship between the voltage and load power at each node of the grid, and is one of the important indicators for voltage control in the distribution network. In order to effectively predict the variation of grid node voltages and develop corresponding voltage control strategies, this paper proposes an integrated sensitivity calculation method for cross voltage levels of unbalanced medium- and low-voltage distribution network (MV-LV distribution network). Firstly, the equivalent model of the transformer under Dynll wiring is analyzed. Secondly, the correlation between voltage, current, and power on the primary and secondary sides of the transformer is established and quantitatively analyzed. Thirdly, the integrated sensitivity calculation method of MV-LV distribution network is derived based on the correlation relations. This method allows for the calculation of inter-voltage and inter-phase sensitivities for MV-LV distribution network. Finally, the Dynll transformer is selected to carry out the case study to analyze the propagation mechanism of power quality and inter-phase power propagation mechanism in the MV-LV distribution network.