Application Study Of Reactive Power Optimization For Foshan Power Grid

Reactive-power optimization of power systems is a sophisticated problem of nonlinear programming. Primal-dual interior point algorithm takes advantage of outstanding convergence performance, fast speed, and dealing inequality constraints, so that it is used to solve various optimization problems of power systems. Meanwhile, the algorithm is not sensitive to system scale, and its iterations cannot increase sharply as system scale increases. Thus, primal-dual interior point algorithm is appropriate to reactive-power optimization of large-scale power systemsThis primal-dual interior point in detail, introduced the basic thinking and model of reactive-power optimization of power systems. According to the character that the model includes the discrete variables, e.g. tap position of transformer and switching of complement capacitor, successive discretization of the discrete control variables in optimization process by incorporating penalty function into nonlinear primal-dual interior-point algorithm is introduced. The numeral results demonstrated the reactive-power optimization efficiently.The primal-dual interior-point algorithm with penalty function was applied reactive-power optimization of Foshan power grid. Comparison of power flow before and after optimization showed that the algorithm cannot also limit the voltage to a reasonable level, improve the overload of line and transformer markedly, but also decrease power loss. On the basis, the selection of condenser capacity and economic operation of transformers were analyzed. In terms of the above results, from the views of technology and management, the optimizing measures and operation advice are proposed, and the index of energy saving and loss reduction was calculated.