A loop-analysis theory based power flow method and its linear formulation for low-voltage DC grid

Abstract

As in alternative-current (AC) networks, the power flow (PF) task is the backbone of direct-current (DC) networks with the development of DC power system. In this paper, it proposes a loop-analysis theory based iterative power flow method for the low-voltage DC (LVDC) power grids. And further the linear power flow model via Taylor's series expansion has also been developed. Based on the node-branch incidence matrix, the relationship between the branch powers and node injection powers has been established. The formation of the proposed iterative method and its linear approximation are derived based on the branch powers rather than the injected currents. ZIP loads and V buses (multi-slack buses) have been taken into account. Simulation results verified the accuracy and speed of the proposed methods in comparison with the classical Newton-Raphson method and two other existing linear methods for both radial and meshed networks.