DISTRIBUTION LOAD FLOW AUTOMATION

Distribution load flow analysis is traditionally developed in a narrow and statical sense and is extremely inflexible from practical viewpoints. These deficiencies, coupled with the recent trend of incorporating new technologies into the distribution level, have in terms justified the necessity of searching for a more extensive and dynamic scope for distribution load flow automation scheme based upon two representative and generalized methods--balanced load flow and three-phase load flow.;For the purpose of extending the distribution load flow analysis to a broader frame of applications, two pertinent and advanced methodologies which constitute the predominant part of distribution analysis are also developed and incorporated into the data base as an integrated automation package--inter-feeder switching and capacitor allocation.;The problem of optimally determining the inter-feeder switching schedule under short-term contingency operation has been solved by simulating the overloading system into a network graph. The essence of this approach is to reflect the actual network structure through a proper construction of arc characteristics. A series of switching steps is generated to optimally change the overloading system into a safe-operation system.;A modular approach composed of three stages has been developed to solve the problem of optimal capacitor allocation on distribution primary feeders. Specifically, all the benefits rendered by the capacitor applications are properly considered and many simplifying assumptions contained in the existing techniques are discarded. The reduced dimensionality and complexity of each subproblem as allowed greater use of existing optimizing techniques and also permitted the solution procedure to adapt to voltage constraints effectively.;A compatible distribution line segment data base has been developed to directly support the complicated data requirements for load flow analysis and also to eliminate the necessary maintenance of linkage between the transformer data base and the line segment data base. In conjunction with a versatile subschema transformation in its corresponding management software, a dynamic environment for distribution load flow analysis has been further realized.;The methodologies and computer program developed in this research have been successfully tested on actual systems of Taiwan Power Company.