Mid-term power system planning based on daily simulation model

January 2002

Abstract

Planning the operation of the electric power system (EES) represents a very complex problem conditioned by numerous techno-economic parameters, largely stochastic in nature, and aims to create an EES operation plan in the observed period that will result in the lowest costs in the system while meeting the required level of operational safety system. Medium-term planning of EES work, which in this work implies a time period of at least one month to a maximum of several months, is conditioned primarily by the size and structure of production capacities in EES, but also by the organizational conditions in which it takes place. Medium-term planning must always be a variant, in such a way as to determine the optimal plan with regard to a wide range of possibilities conditioned both by stochastic parameters (hydrology, thermal power plant outages, changes in consumption) and by planning decisions at the medium-term level (use of reservoirs, engagement of thermal power plants, import contracting /electricity export, etc.). Through the research in this paper, a simulation-optimization model of EES work planning at the daily level was conceived and realized, on the basis of which different synthesis models of the medium-term work plan of EES were defined. The medium-term work plan provides variant work balances of the EES, which are the basic basis for important planning decisions such as import/export of electricity, fuel procurement, changes in the planned regime of use of reservoirs, etc. The medium-term planning models of the EES work are elaborated on three levels: a pure deterministic model with the possibility of variant analysis, an upgrade with a probabilistic model for the calculation of expected production, variable costs and safety parameters of the EES operation, and finally an upgrade with a Monte-Carlo simulation model that provides the greatest possibilities for creating a medium-term EES work plan for an arbitrarily selected set of input parameters given by appropriate probability density functions. All levels are accompanied by appropriate examples that show part of the results of the medium-term work plan for a concrete example of the work planning of the EES of Croatia. The fundamental area of application of the conducted research primarily refers to the operational medium-term planning of the operation of a smaller-sized mixed hydro-thermo system, as a basic tool for the decision-making model and energy-economic-security valorization of decisions about the way to use available production facilities, water from reservoirs and decision-making on the medium-term purchase or sale of electricity, which includes an appropriate analysis of possible economic risks that follow from planning decisions. The proposed methods of medium-term planning of EES work can be equally well used in the centralized-monopolistically organized electricity industry, as well as in the deregulated one. to the market-organized EES, clearly with a corresponding extension that includes models for forecasting electricity prices in the observed planning period. In addition, the results of the conducted research showed additional possibilities of application in areas of EES operation planning that are not primarily related to medium-term planning, such as daily EES operation planning, planning of the construction of new production facilities, testing and operation planning of individual power plants/ hydropower subsystems, etc.

Type

Thesis