Modified power flow calculation method of distribution grid with DGs

The distributed generations (DG) result in some problems in power flow calculation when more and more DGs are connected into power system. The algorithm of solving PV nodes in back/forward sweep calculation is improved based on the existing power flow algorithm. The next iterative current value can be obtained via the directly renewed voltage variables, and it does not need to update the reactive flow. The admittance matrix is derived to adapt small load and accurately handle the power flow in small load with DGs. Plenty of simulations are carried out on the IEEE33 bus test system. The results prove that the algorithm can effectively solve the grid connecting problem in PV nodes and small load situation.