Study On The Real-time Optimal Dispatch In Deregulated Environment

Dispatch of power systems is a large-scale optimization with many control variables and constraints. This problem is traditionally decomposed into several sub-problems which can be solved one by one respectively by existing methods. Recently, the operators must face with a large amount of measurement data and economic information, so an automatic system is needed to help them operate the power system. For this requirement, systematic analysis of a real-time optimal dispatch system (RTODS) has been carried out in this dissertation.In the deregulated environment, the dispatch of power systems has two primary specialties: splitting of plants and network and unbundling of energy services. By analysis of ancillary services'trading mode and dispatch procedure, the active-reactive power joint trading model is presented.In order to make the trading results dispatchable and controllable, several functions are integrated to build a practical dispatch system, whole framework of which is presented in this dissertation. By the analysis in a three-dimensional space formed by time scale, optimization objective and control measure, the relationship among the three dimensions are analyzed. The vertical harmonicity considers the coordination between RTODS and short-term scheduling system, and as well between RTODS and online close-loop control systems. In time dimension, multi-level coordinating, level-by-level adjustment is presented. In optimization objective dimension, transit from economy-oriented optimization to security-oriented dispatch is presented. The horizontal harmonicity considers the treatment of the strong coupling constraints in the de-coupled algorithm. The deficiency of several traditional methods is analyzed and the coordinating optimization is presented.More attention is paid to the weak subject and the lacking term in the RTODS framework. Because AGC hasn't considered the constraint of branch limitation, as an improvement, the method of RTODS keeping some transmission capacity for AGC is presented. The concrete transmission capacity is deduced and the practical algorithm is presented. The relationship between preventive control and corrective control is analyzed and the...