A Three-Phase Distribution Power Flow with Neutral Voltage Variables Considering

In ungrounded distribution systems, the constraint condition that the neutral current is 0 should be considered. To meet this constraint, the active power of PQ nodes and PV nodes is taken as variables in the existing power flow calculation, which leads to the difference between the calculated value and the specified value for active power of PQ nodes and PV nodes. To solve this problem, a distribution power flow method with neutral voltage variables is proposed. In the proposed method, the injection current Newton method is used to solve the three-phase power flow problem, the real and imaginary parts of the node voltage and the neutral voltage are selected as variables, the admittance matrix and Jacobian matrix including the neutral node are formed, and the node current mismatch equations including zero neutral current are established; The voltage correction is obtained by solving the mismatch equations. The results of the IEEE-4 node test system and 292 node system verify the accuracy and rationality of the proposed method.