A piecewise parallel solution of current mismatch based Newton-Raphson power flow

This paper proposes a piecewise parallel solution to the Newton-Raphson power flow problem using the concept of current mismatches, instead of power mismatches. The given large network is divided into a number of smaller sub-networks. Computations are performed upon the individual sub-networks. Then the sub-network solutions are consolidated to obtain the solution of the original network using the Large Change Sensitivity concept. No restrictions are imposed on the number and size of the sub-networks in this method. Also, complications such as temporary slack bus assignment for each sub-network and bus reordering do not arise. The number of iterations required for convergence remains exactly the same as that for the original undivided network. The proposed algorithm is tested on 118, 300, 2383, 6515, 9241 and 13659 bus test systems. For large systems, a speed up of 5 to 6 times is obtained compared to the sequential current mismatch based solution.