Visually integrated modeling for distribution network operation and planning

Abstract

Load flow, fault current calculation and protective relay grading are usually individual programs, which are normally run one at a time. A versatile distribution system simulation known as VIPCROP, which integrates load flow, fault current calculation and modeling of overcurrent relays and breaker operation, is proposed and developed. It is aimed to provide a visually integrated tool for operational planning, assessment of overcurrent relay settings, evaluating network proposals and for real-time fault diagnosis and supply restoration. The simulator implements the SCADA type of full graphic display of the single-line diagram superimposed with the calculated line current flow during normal condition, and the calculated fault current distribution and breaker tripping time during fault conditions. In contrast with the conventional load flow and fault current calculation programs, the proposed simulator-type of approach enables the user to operate a circuit breaker, activate a fault at a particular location, start a large motor at a particular bus, or change a transformer's tap-ratio. The immediate effects of the user's operation are modeled and the results are visually displayed on the single-line diagram similar to the real time display of operating a network in a control center. In addition, while operating the system, the user can visually modify the network such as adding a new bus, a new line or changing the settings of a particular relay. Thus, it serves as a very useful tool for both network operation and network planning.