A successive approximations method for power flow analysis in bipolar DC networks with asymmetric constant power terminals.

This paper deals with the power flow problem in bipolar direct current distribution networks with unbalanced constant power loads. The effect of the neutral wire is considered in two prominent cases: (i) when the system is solidly grounded at each load point and (ii) when the neutral terminal is only grounded at the substation bus. The problem is solved using the successive approximation power flow method. Numerical results in two test feeders composed of 4 and 25 nodes demonstrate that the successive approximation power flow approach is adequate to solve the problem. It is also demonstrated that it is equivalent to the backward/forward power flow in matrix form. The main advantage of both power flow approaches is that they can work with radial and meshed distribution networks. Additionally, they do not require inverting matrices at each iteration, making them efficient in terms of computational processing times requirements. All the simulations are carried out in the MATLAB programming environment. • Bipolar DC networks have the double transference capability of their monopolar DC networks. • Convergence of the successive approximation power is ensured through the application of the Banach fixed point theorem. • Power losses increase for the topology with non-grounded neutral wire. • Monopolar unbalanced loads produce voltage imbalances between the positive and negative poles. [ABSTRACT FROM AUTHOR]