Estimating the Hydroelectric Power Plant Performance Indicators Subject to Grid-Related Constraints on the Power Output

Abstract

The aim of the study is to evaluate the extent to which the generating capacities of hydroelectric power plants (HPPs) are underutilized during their joint operation with thermal power plants (TPPs) in a grid under high water conditions.

The data on constraints imposed on the operation of power plants in different periods of time for determining their operation intervals were studied based on reported information on the market operation modes for a day ahead.

The analysis was carried out for joint operation of HPPs and TPPs in years characterized by different abundance of water resources. Data for the Interconnected Power System of Siberia and two typical periods, namely, an average working day in January and an average working day in June were taken as an analysis example.

For each of the considered HPPs, their initial participation was made in the grid load curve: in the load curve base part according to the above-mentioned base part and the HPP monthly average power, and in the load curve peak part according to monthly average and working power (minus their operation in the load curve base part). The participation of the HPPs was determined taking into account the technical and technological minimums of TPP operation.

The procedure of determining the participation of power plants is iterative in nature and uses the method of golden section for selecting the parameters characterizing the power plant participation in the load curve and the power capacity margin.

It follows from the obtained results that in January, the limitations relating to the TPP operation mode impose no constraints on the operation of HPPs. However, in the June load curve, in which the influence of water abundance on the HPP operation mode is much more significant due to the HPP operational requirements, the HPSs cannot operate at their full capacity; that is, the extent to which the HPP capacity is underutilized depends on the water abundance in a year.

By using the developed algorithm, it is possible to estimate the amount of HPP generating capacity underutilized in an interconnected power system. The underutilized power generation capacity of the Angara-Yenisei HPP chain in the Interconnected Power System of Siberia can be used for generating and transmitting power to the European part of the UES of Russia, e.g, to compensate the insufficient output of HPPs in the Volga-Kama chain during low water periods.