Path matrix based three-phase distribution power flow algorithm with multiple distribution transformer branches

Abstract EN

In order to analyze the power flow in the distribution systems with multiple distribution transformer (DT) branches, a three-phase power flow algorithm was developed based on the path matrix.

By studying the special topological structure of distribution system, an incident matrix between node voltages and injection currents was established, which could make direct solution possible.

In the algorithm, a detailed DT model was developed, considering winding connections, phase shifting and off-nominal tap ratio.

The model solved the problem of singularity of DT admittance matrix also.

And then, an equivalent model for the branch with DT was constructed based on the proposed DT model.

Through correcting path matrix, the proposed algorithm could handle the branches with various winding connection DTs in an unbalanced system with multi-voltage levels.

Because the branch with DT was treated as a normal line branch, the algorithm had faster computational speed, simple calculation process.

The results of IEEE 4-bus test system and the modified IEEE 34-bus test system verified the correctness and good convergence of the proposed algorithm.