Distribution load flow methods for shipboard power systems

With the initiatives to modernize large ship power systems, ship builders are integrating technologies with the aim of an all-electric energy system. Integrated power systems provide total ship power including motor-drive propulsion, service and hospitality loads, and mission-defined load configurations. New control strategies permit distribution automation and network reconfiguration. The system objective is to provide flexibility and control in directing where power is needed with a high level of reliability and quality. The automated controls require efficient and accurate load flow solutions in monitoring and regulate the power system. A critique of classical and distribution power flow methods is conducted for shipboard distribution automation. Three classical radial-network power-flow methods are reviewed. Modification of a forward-backward sweep method, enhancing the computation time and solution convergence is presented. Comparative tests are conducted on a new benchmark test system of a ship´s distribution network. The results demonstrate that the modified forward-backward sweep method succeeds in being the fastest methods with good convergence on networks with high R/X ratios.