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Load-Flow Analysis

Load-flow analysis examines steady-state equations based on the positive definite network admittance matrix that represents the power system distribution network. Load-flow analysis is used for identifying potential network problems in contingency analyses, for examining steady-state operations in network planning and optimization, and also for determining initial system state in transient stability calculations [44]. Load flow analysis entails the solution of non-linear systems of simultaneous equations, which are performed by repeatedly solving sparse linear equations. Load flow is calculated using the network admittance matrices, which are symmetric positive definite and have sparsity defined by the power system distribution network. The size of these matrices is limited because individual power systems generally use networks with less than 2,000 sparse complex equations in their operations centers, while regional power authority operations centers would also be limited to sparse load-flow matrices with less than 10,000 sparse complex equations. Power systems planning studies often incorporate larger networks as lower voltage distribution lines are included in these studies. Sparse matrices employed in planning studies can have from 10,000 to 50,000 sparse equations. This paper presents data for power system networks with 1,723, 5,300, 6,692, 1,766, and 9,430 nodes.



David P. Koester
Sun Oct 22 15:31:10 EDT 1995