Three very different methods of accomplishing the same task-managing the operation of the transmission system in the deregulated power system operating environment-have been implemented as deregulated market structures have been created around the world. They are first, the optimal power flow (OPF) model found in various implementations in the United Kingdom, parts of the United States, and in Australia and New Zealand. Second, the point tariff, price area congestion control model used in the Nordpool market area in Norway and Sweden. Third, the US transaction-based model. All are pragmatic solutions implemented in advance of complete theoretical understanding. Each has strengths and flaws, and there are some surprising inter-relationships. Each maintains power system security but differs in its impact on the economics of the energy market. No clearly superior method has so far emerged. In the future, methods of combining decentralized market solutions with operational use of optimal power flow may provide better solutions to existing and emerging problems.

Visualization techniques are applied to an electric power system transmission network to create a graphical picture of network power flows and voltages. A geographic data map is used. Apparent power flow is encoded as the width of an arrow, with direction from real power flow. Flows are superposed on flow limits. Contour plots and color coding failed for representing bus voltages. A two-color thermometer encoding worked well. The resulting visualization is a significant improvement over current user interface practice in the power industry.>