Procedure for scheduling power generation at HPP in the second quarter with allowance for run-off-forming and climatic factors

Abstract

A procedure is developed for analysis of scheduled generation at HPP using run-off-forming data relative to water reserves.To organize reliable fuel and energy supply, it is necessary to schedule power generation at hydroelectric plants (HPP) with maximum lead time [9]. The procedures currently used for the scheduling of power generation at HPP are based on data relative to the forecasting of water flow in river basins, or on scheduled generation normally adopted as the average-multiyear value. These forecasts are short-range, since the volume of inflow becomes known with little lead time.The scheduling of power generation in the second quarter for HPP is critical, since scheduling errors will make themselves felt during subsequent operation of the HPP throughout the reminder of the year. Fulfillment of scheduling indicators on the high side for power generation at HPP will result in excessive drawdown of the reservoirs, and inevitable significant losses in generation in subsequent months of the year. In isolated power systems with a predominance of hydraulic capacities, such overestimation is also fraught with disruption in power supply to consumers.Underestimation of power generation at HPP will result in the need to off-load its surpluses to the wholesale market, which cannot always be done considering constraints placed on the regimes of other generating sources.Of the basic factors affecting power generation at HPP in the second quarter, it is proposed that run-off-forming (water locked in snow that has fallen over the entire watershed for site in question) and climatic (characteristic features of atmospheric circulation) factors be utilized.We examined three alternative models: consideration of the individual effect of each of the above-indicated factors on power generation at HPP in the second quarter, and consideration of their combined effect.The goal of this study was to develop a procedure ensuring maximum timeliness in the prediction of power generation with observance of its accuracy requirements.Testing of the procedure was approved for the Rybinsk HPP on the Volga River, and the Votkinsk HPP on the Kama River. Here, annual data on water locked in snow during the period of observance from 1980 through 1998 with a ten-day measurement frequency from January through March, and indicators of characteristic features of atmospheric circulation over the northern hemisphere (from 40°N and higher) from 1980 through 1998 with a monthly measurement frequency were used.The period from 1980 through 1998 was adopted for derivation of a computational model. Estimates of the quality of values forecast for power generation at the HPP in the second quarter were made on the basis of statistical methods for the period from 2002 through 2006.The influence exerted on power generation at the HPP only by the water locked in snow that had fallen over the entire watershed of the HPP sites under consideration was considered in the first alternate structural scheme of the model.Analysis of scheduled power generation was based ...