Irina Golub

A technique for calculation of nodal gas prices and analysis of their components

Consideration is given to the technique for calculation of nodal gas price and all its components on the basis of a two-stage approach, i.e. calculation of the optimal gas distribution in gas supply system (a direct solution of the linear programming problem), marginal prices (a dual solution) and their decomposition into components by the graph-based cost allocation method. It is shown that the price components are determined by the gas production and transportation costs as well as by the marginal markups for reaching the limit values in gas production and transportation. Simultaneously, the similar price components related to gas losses are found. The technique of the nodal price calculation is illustrated by the example of the Unified gas supply system in Russia. The nodal gas price components were studied on the basis of the retrospective information on gas production and consumption in the constituent entities of the Russian Federation (RF) in 2005. The paper shows the relationship among different components of the nodal price.

Approach to choice of controls for probabilistic constrained load flow in the electric power system

In the paper the methods of probabilistic load flow, including linear method of generalized disturbance, are used to detect sensor variables in an electric power system, identify their probabilistic characteristics, detect critical variables, for which the probability that they lie in the feasible range is lower than the required one, and select the control actions to increase this probability. The controls are selected by the method similar to the method of deterministic equivalent by subsequently and iteratively solving deterministic and probabilistic problems. The tracing method makes it possible to choose from a set of possible controls a vector of control that contains the minimum number of components. The presented numerical results on the example of real network demonstrate the efficiency of the proposed approaches to the electric power system operation control.