Simplified Newton–Raphson power-flow solution method

This paper presents a simplified version of the well-known Newton–Raphson power-flow solution method, which is based on the current balance principle to formulate a set of nonlinear equations. Although there exist several powerful power flow solvers based on the standard Newton–Raphson (NR) method, their corresponding problem formulation is not simple due to the need for calculation of derivatives in their Jacobian matrix. The proposed method employs nonlinear current mismatch equations instead of the commonly-used power mismatches to simplify overall equation complexity. Derivation of Jacobian matrix’s updating formulae is illustrated in comparison with those of the standard Newton–Raphson method. To demonstrate its use, a simple 3-bus power system was selected as a numerical example. The effectiveness of the proposed method was examined by computer simulations through five test systems: (1) 5-bus test system, (2) 6-bus test system, (3) 24-bus IEEE test system, (4) 30-bus IEEE test system and (5) 57-bus IEEE test system. Its convergence and calculation time were observed carefully and compared with solutions obtained by the standard NR power flow method. The results show that the proposed NR method spends less execution time than the standard method does with similar convergence characteristics.