Research on second-order cone relaxation algorithm for multi-time linearization of distribution networks with distributed power sources

Abstract

Distributed power supply connected to distribution network brings impact on system voltage distribution as well as tidal current analysis, which causes degradation of system power quality. For this reason, a system optimization model is needed to analyze and optimize system voltage and tidal current. The linearized second-order cone relaxation optimization algorithm for distribution networks with distributed power sources is proposed. First, the distribution network branch tide model is introduced to analyze the tide of the distribution network with distributed power supply access; based on this, the distributed distribution network tide optimization model is established. Secondly, the distributed distribution network tidal optimization model is simplified, and the multi-time second-order cone relaxation optimization algorithm is proposed for the non-convex nonlinearity in tidal analysis, and the segmental linearization is performed for the non-convex nonlinearity of capacitor bank and on-load regulator transformer. Finally, a modified IEEE33 node test system is used on the MATLAB simulation platform to verify the tidal optimization of this distributed distribution network tidal optimization system. The simulation results show that the tidal optimization algorithm can reasonably dispatch the output of on-load regulating transformers, capacitor banks and distributed power sources, effectively reduce the network loss and the voltage deviation of the grid.

Distributed photovoltaic hosting capacity assessment technology considering stable operation of distribution network

“…The national standard "Technical Requirements for Grid-connected Distributed Power Supply" stipulates that the distributed photovoltaic power factor adjustment range is 0.98 (lead) ~ 0.98 (lag), according to which the maximum positive and negative reactive power injection Q ' can be estimated. The allowable positive and negative voltage deviations caused by distributed PV access are estimated U ' and U ' according to the voltage timing of all bus levels during the evaluation period and the voltage deviation limits specified in the national standard "Voltage Deviation of Power Quality Supply" [5] . Then, it is checked according to the following equation.…”