Improved Power Flow Methods for DC Grids

This paper presents a steady-state model and associated power flow equations that can be applied to any dc grid. State-of-art power flow methods and two newly proposed methods are discussed and applied to the proposed steady-state model. A standardized IEEE test feeder is used to benchmark the power flow methods with respect to accuracy, convergence and computational efficiency. It is shown that the two new methods have a superior performance compared to the existing techniques for the steady-state analysis of most common dc grids, providing up to a 93 % increase in computational efficiency for the system that was analyzed in this paper. Therefore, it is demonstrated in this paper that these power flow techniques can be used for the operation, planning, optimization, market simulation, and security assessment of practical dc grids.